Samenvattingen bij de voorgeschreven artikelen van Brein en omgeving (UU) 21/22

Why is the ability to realize the fullest potential of scientific knowledge paradoxically limited by the disciplinary paradigms that have led to the growth of scientific knowledge?

Recent scientific advantages have caused an explosion of knowledge about how children develop and how contextual factors influence their development. At the same time, the particular disciplinary structures and paradigms often reflect and cause delimited questions, measures, and frameworks. Research teams often lack disciplinary and cultural diversity and publish mostly in their own disciplinary journal. The existence of lots of field-specific knowledge from biology, neuroscience, psychology, and the social sciences is therefore hard to synthesize.

What is developmental systems theory?

Developmental systems theory (DST) is a theoretical perspective on development, heredity, and evolution. It emphasizes the shared contributions of genes, environment, and epigenetic factors on developmental processes. It views development as an ongoing, constructive enterprise between the individual and multiple biological, psychological, and sociocultural systems and agents over time.

What are the two basic principles of DST?

Developmental systems theory is based around two basic principles:

• Multiple characteristics of individuals and context collaborate to produce all aspects of behavior.
• Variability as well as stability in performance provide important information for understanding human development.

How can DST help integrate the vast amount of scientific knowledge about human development?

DST provides a framework for seeing how factors within an individual and his/her micro- and macro-environments act together to shape how children learn, change, and systematically grow across the developmental continuum. It helps in reviewing the variability in behavior and performance of children and adults. DST offers a means to organize and explain complex relations involving biological and physiological systems, social environments, and appraisals, interpretations, and internalizations of our experiences shape pathways across life and provide opportunities to optimize development.

Which important themes can be found when integrating knowledge from multiple scientific disciplines about human development?

• Human development depends on the ongoing, reciprocal relations between individuals´ genetics, biology, relationships, and cultural and contextual influences.
• Each individual´s development is a dynamic progression over time.
• The human relationship is a primary process through which biological and contextual factors mutually reinforce each other.
• All children are vulnerable. In addition to risks and adversities, micro- and macro-ecologies provide assets that foster resilience and accelerate healthy development and learning.
• Students are active agents in their own learning with multiple neural, relational, experiential, and contextual processes converging to produce their unique developmental range and performance.

What is epigenetic adaptation?

Epigenetic adaptation is the biological process through which the ecology of relationships, experiences, perceptions, and physical and chemical toxins influence lifelong learning, behavior, neural integration, and health. Epigenetic signatures are chemical signals derived from environmental influence. They affect when and how genes are switched on and off, and whether the change is temporary or permanent. This is a process that begins before conception and contributes to the transmission of behaviors and experiences to future generations, as well as to qualitative changes in our genetic makeup.

What are foundational skills?

Foundational skills are skills that all children need for healthy development and learning, including the bonds that children make with adults (which provide emotional security), the skills to cope with and manage stressful situations, and the regulation of emotion and attention to effectively engage and accomplish goals.

What is dynamic skill development?

Dynamic skill development refers to the human brain´s capacity to act in an organized way in a specific context. Skills do not emerge fully formed, but are built up through practice in context in a constructive process over time. Skill construction is an active process with an interdependent, hierarchical character: complex skills emerge as earlier skills are integrated into an inclusive whole. Skills vary within individuals based on goals, emotional states, and contextual supports. A child´s performance can be optimized under conditions of high, personalized support.

How does relational integration influence human development?

Relational integration is found in strong interpersonal connections that respect each other´s autonomy and individuality while linking him/her in empathic communication with others. It promotes neural integration and leads to strengthened links between existing synapses, regions, and functions that are critical for the development of more intricate brain processes and skills. Positive developmental relationships are characterized by warmth, consistency, attunement, reciprocity, and joint activity. These relationships are necessary for developing the affective, cognitive, social, emotional, and behavioral competencies that are foundational for developing and learning.

Why is relational integration especially important in the first year of life?

Sensory, social, and emotional experiences offer opportunities to optimize foundational brain circuits. Early attunement balances excitatory and inhibitory systems in the brain and establishes templates for coordinated interpersonal behaviors, attitudes, and expectations about the self, others, and relationships. It makes a healthy development of the neurobiological systems involved in cognition, stress modulation, and self- and emotional regulation possible.

Which developmental patterns characterize variation in infants´ attachment?

Children develop a working model of close relationships grounded in early experiences. Three developmental patterns can be distinguished:

• Secure attachment with caregivers supports development through opportunities to explore surroundings, build language skills through language-rich and responsive interactions, and build social competence through successful social interactions.
• Insecure avoidant
• Insecure anxious/ambivalent

Sometimes a fourth pattern is added, namely disorganized attachment, which is associated with abuse and trauma.

What is self-regulation?

Self-regulation skills and attributes are a foundational set of competencies that help with managing cognition, emotion, attention, and action, and support goal-directed behavior. They involve multiple regulatory-related processes that range from automated physiological functions to effortful, complex cognitive processes. Self-regulation is a complex dynamic skill and is formed through many interrelationships between and among various subskills and collaborating internal systems.

What is the role of self-regulation in human development?

By stimulating the brain´s self-organizing and reorganizing properties and integrating subsystems of skills, the continuous feedback loop between emotion regulation, executive functions, motivation, and stress management creates the capacity to self-regulate. Self-regulation skills are important for higher-order learning (e.g. decision making, problem solving), metacognition, conflict resolution, perseverance, and resilience, and contribute to short- and long-term social, emotional, cognitive, academic, financial, and health outcomes.

What is intentional self-regulation?

Intentional self-regulation occurs when a person consciously sets out to attain a goal and/or when routine activities are impeded. It is a constructive process whereby children set goals for their learning and then continue to monitor and control their cognition, metacognition, motivation, and behavior based on the assessment of their goal attainment. Intentional self-regulation skills include effortful control, the ability to implement goal-related strategies, and the ability to optimize goals to align with personal and social values and desired abilities.

What are executive functions?

Executive functions are a set of neurocognitive attention-regulation skills involved in the conscious, goal-directed modulation of thought, emotion, and action. They involve both top-down, intentional control of behavior as well as bottom-up, automatic reactions. Commonly the executive functions consist of attention control, cognitive flexibility/attention shifting, working memory, and inhibitory control.

What is the role of the executive functions in human development?

The development of executive functions begins early and can be intentionally nurtured, for example by preparing children to pay attention, follow rules, and actively engage in learning. They are necessary for more complex self-regulation-related skills, such as focus, self-control, communication, and engaged learning. The executive functions are very important for learning readiness and school success.

What is the science of individuality?

Science of individuality is a framework that believes that individuals vary in how they learn, behave, and develop, that these processes vary according to context, and that there are patterns within that variability. It doesn´t believe in the existence of one ideal developmental pathway for everyone, but instead strives to understand patterns in individual variation across contexts to be able to build toward generalizable models of growth and learning.

What is the Specificity Principle?

The Specificity Principle views development as multidimensional, modular, and reflective of the interactive context of a child´s life, producing distinctive pathways across time and at specific points in time. It looks at the moderating influence of practices and interventions to produce a specific set of competencies, behaviors, performances, or growth. Researchers, according to the science of individuality, should assess developmental pathways of different individuals through this principle, to be able to capture the range of variability in human development and skill acquisition.

What is the “constructive web” when applied to learning processes?

The constructive web is a framework through which to understand the dynamic interrelationships between children’s development, knowledge, complex skill constructions, and environmental supports. When applied to learning processes it:

• Acknowledges the many relational, curricular, instructional, and environmental factors that support or undermine learning.
• Recognizes that skills do not emerge in isolation or a complete form, but codevelop hierarchically through multiple domain-specific practices in context.
• Assumes the need for effective scaffolding, sequencing, and pacing within a child´s unique developmental range.
• Characterizes students´ learning trajectories as joint products of their individual attributes and the dynamic web of contextual supports that surrounds them.

How do prior knowledge and experiences influence the learning process?

The prior knowledge that children have before they come to school is what formed their automated beliefs, attributions, conscious and unconscious knowledge, and metacognitive and cognitive skills. It affects how children receive and process new information. Teachers should try to connect to this prior knowledge to engage the children in the learning process and to increase their neural integration and learning of new information. 

How does motivation influence the learning process?

Motivation is a psychological process that determines whether students begin a task, persist at it, and invest mental effort to succeed. Intrinsic motivation is associated with deeper focus, confidence, creativity, and achievement. Research shows that motivation accounts for a large part of learning, as well as the transfer and application of what has been learned.

How do competency-related beliefs influence the learning process?

Competency-related beliefs are beliefs about what one is capable of with regard to a particular task or situation. When students feel competent and believe that their intelligence and ability can be improved through effort, and when they feel in control of their learning, they are more motivated to learn and are more effective learners.

What is the Belief-Control-Expectancy Framework?

The Belief-Control-Expectancy Framework suggests that student beliefs about themselves and their learning goals influence expectations about what they are able to control. There are four factors in the framework, namely values, self-efficacy, emotions, and attribution errors. These factors influence beliefs about control and expectancies for success, and influence a student´s ability to start, persist, and apply sufficient mental effort to complete and succeed at a task.

How does metacognition influence the learning process?

Metacognition is the awareness of one´s own thinking and learning. Metacognitive skills enable students to process, manipulate and refine information, to organize and recognize patterns in information, to evaluate their thinking and learning strategies, to intentionally transfer knowledge to new situations, and to apply knowledge to solve complex problems. Metacognitive processes support neural integration and enables students to learn from their mistakes. Finally, metacognitive abilities can enhance motivation.

What are the conditions for learning?

The conditions for learning (CFL) refer to the relational dimensions of learning, physical and emotional safety, and a sense of belonging and purpose. CFL have direct and indirect effects on learning, and can be positive or negative. Students learn best when the conditions for learning:

• Promote motivation, engagement, and purpose.
• Ensure emotional, physical, and identity safety.
• Foster connection, respect, support, and challenge.

Very important within the conditions for learning is the presence of positive developmental relationships between students and teachers.

How can cultural responsiveness and competence create positive conditions for learning?

Cultural incompetence heightens anxiety and stress, and places extra demands on working memory and cognitive resources. Cultural competence contributes to effective learning by addressing or preventing factors that directly interfere with student´s learning and by creating supportive environments and personal readiness in adults to address cultural disconnects and disabling conditions. Through context-sensitive communication between the teacher and the student, the relational and neurobiological conditions for learning can be enhanced (for example by using cultural knowledge as a scaffold to connect existing knowledge to new concepts and content).

How can stress influence learning?

During a stress response the hormonal and neurochemical systems in the body are activated. The body produces cortisol and adrenaline, two hormones that increase heart rate, blood pressure, inflammatory reactivity, and blood sugar levels. This heightens vigilance and alertness, but reduces nonessential functions such as complex thinking. Also, exposure to chronic stress is associated with changes in brain architecture and the development of the brain structures and their integration.

Which types of stress responses have been identified by the American Academy of Pediatrics?

Three types of stress responses have been distinguished:

• A positive stress response is characterized by mild and/or brief elevations in stress hormones, heart rate, and blood pressure. It is part of a healthy child development.
• A tolerable stress response activates the body´s alarm systems to a greater degree due to more severe or longer-lasting threats. But, in the presence of supportive relationships, long-term physiological effects can be prevented.
• Toxic stress responses occur when stress exposure is frequent, prolonged, and without the presence of adequate adult support. The chronic elevation of stress hormones can disrupt the maturation of the developing brain and physiological systems, with negative implications for learning.

What is resilience?

When referring to individuals, resilience can be defined as the potential or manifested capacity of an individual to adapt successfully through multiple processes to challenges that threaten the function, survival, or positive development. Resilience is not a trait, but best characterized by substantial heterogeneity, dependence on contextual supports, and equifinality. Children´s resilience varies as a function of individual sensitivities and dispositions, socialization practices, the type, timing, and intensity of adversities, and the support they have available to them.

What are the principles of the developmental systems perspective on resilience?

• Human adaptation and development in continuous, multilevel coactions with the environment.
• Multiple interacting systems.
• A capacity for adaptation conceptualized at multiple levels.
• Manifestations of resilience reflecting current and historical contexts.
• A capacity for adaptation in challenging circumstances involving multiple interacting systems.
• Constant change and adaptation.
• Self-organizing properties.
• A recognition that resilience is not a fixed trait, but emerges through coaction with contextual, supportive, and relational factors.

What general principles are essential for understanding the developmental dynamics of fetal and baby brain?

• Developmental events occur in specific architectonic compartments, such as embryonic and fetal zones. 
• The compartments are transient, but can be visualized in historical sections and MR images.
• To be able to understand the development of functional connectivity, the nature and timing of development of basic connectivity elements and their molecular properties need to be analyzed. 

What are important events in brain development in the early fetal period (eight to fifteen postconceptional weeks)?

• There are processes of proliferation, migration, and cell aggregation. 
• All embryonic brain divisions and their major subdivisions are clearly visible on coronal sections at the end of the embryonic period.
• The formation of the cortical plate is an important cytoarchitectonic event. After its formation, the cerebral wall of the lateral neocortex consists of the marginal zone, the cortical plate, the presubplate, the intermediate zone, the subventricular zone, and the ventricular zone. 
• According to the radial unit hypothesis, the cortical neurons are generated in proliferative units of the ventricular zone, migrate along radial glial guides and settle in vertical ontogenetic columns within the cortical plate. 
• With regards to the growth of early afferents to the human cerebral cortex, thalamocortical fibers pass through the cerebral stalk, cross the diencephalo-telencephalic and subpallio-pallial border and fan out within the intermediate zone on their way to the cortical anlage. Basal forebrain fibers reach the neocortical cerebral wall through the external capsule. Corticospinal and corticopontine pathways are located medial to thalamic radiation and are partily intermingled with it. 
• The first synapses in the neocortical anlage appear. 
• There is a trilaminar pattern of organization consisting of the cortical plate, the intermediate zone, and periventricular proliferative zone. 
• Changes in cell aggregation (cytoarchitectonics), proliferation and migration, neuronal and dendritic differentiation, and axonal growth.

What are important events in brain development in the midfetal period (fifteen to twenty three postconceptional weeks)?

• Four histogenetic-neurogenetic events are most important during this period: neuronal aggregation and cytoarchitectural development, axonal outgrowth and ingrowth, dendritic differentiation, and molecular specification.
• The formation of synapses continues in the subplate and marginal zone. 
• Molecular specification of cerebral cortex can be divided in two processes, namely the areal specification and the specification of subsets of cortical neurons. 
• Major protection and commissural pathways are still growing (think of corticostriatal, corticospinal, thalamocortical, corticopontine, and corpus callosum).
• Associative pathways are not well developed, except for associative fibers connecting frontal cortex with cingulate neocortical portion of the limbic lobe.
• The presence of synapses in the subplate and the dense distribution of synapses in the marginal zone indicate circuitry development.

What are important events in brain development in the late fetal period (twenty four to thirty four postconceptional weeks)?

• Three histogenic and neurogenetic processes are most important during the beginning of the late fetal period: ingrowth of axons, synaptogenesis, and dendritic differentiation of pyramidal neurons.
• Rapid development of primary sulci and gyri. The central, precentral, and postcentral sulcus delineate the developing precentral and postcentral gyrus. Superior and inferior temporal sulcus appear in the temporal lobe. Superior and inferior frontal sulci mark the position of future superior, medial, and inferior frontal gyrus in the frontal lobe.
• On the medial hemispheric surface, there is deepening of the parieto-occipital and calcarine fissure and the appearance of the cingulate sulcus.
• Gradual decrease in the intensity of neuronal proliferation in ventricular and subventricular zone.
• At the end of the late fetal period secondary sulci develop rapidly, there is an increase in the volume of the cerebral wall, and there is a decline in proliferative zones.
• During the end of the late fetal period, the most intensive histogenetic events are neuronal aggregation, cytoarchitectonic changes in laminar pattern, axonal ingrowth and outgrowth, dendritic differentiation, and synaptogenesis in the cortical plate.

What are important events in brain development in the neonatal period?

• The main event is the formation of tertiary gyri.
• There are advances in neuronal aggregation and cytoarchitecture, with parallel establishment of tangential and radial patterns. There is gradual resolution of layer IV in the premotor cortex and the disappearance of this layer in the motor cortex, resolution of the voluminous subplate and its transformation into a characteristic thin band at the interface between layer VI and the gyral white matter, and an increase in size of pyramidal cell bodies.
• There is growth of short corticocortical fibers.
• Dendritic differentiation.
• Synaptogenesis.
• Myelination and increase in compactness of axonal pathways.
• Cell death and axonal pruning.
• The proliferation and migration of neurons have ceased, while the proliferation of astrocytes and oligodendrocytes is continuing.

What are important events in brain development in early infancy?

There is a rapid and massive increase in the total brain volume during the first year. The elaboration of cortical gyrification continues. Some histogenetic processes rapidly increase in intensity (such as synaptogenesis and dendritic differentiation), while others follow a steady pace (such as cytoarchitectonig development, neurochemical maturation, and myelination). There is a decline in the growth of axonal pathways.

What are important events in brain development in late infancy?

The cerebral hemispheres continue to grow. The most intense histogenetic and neurogenetic events during this period are morphological differentiation of neurons and dendrites, synaptogenesis, myelination, and changes in cortical cytoarchitectonics.

What does the period of brain development until the age of 2 years old entail?

The period until the age of 2 years old is characterised by the most dynamic period of brain development. From birth to 2 years of age, the overall brain size increases dramatically, reaching close to 90% of adult volume by the age of 2 years. The gray matter volume also reaches a lifetime maximum at around 2 years of age. These structural changes in the brain are accompanied by the process of brain circuit formation, as a result of neurogenesis, neuronal migration, synapse formation, dendritic arborisation, axonal growth, pruning and myelination. These processes shape the structural and functional architecture of the human brain.

Despite the significant contribution of histological studies to understanding typical and atypical brain development, these studies are relatively labor-intensive and time-consuming and may not be suitable for surveying the entire brain. Therefore, it is extremely difficult to reveal the global maturation pattern of the white matter or the cerebral cortex with histological approaches alone. Magnetic resonance imaging (MRI) techniques, on the other hand, are able to survey the entire brain in a very time-efficient way.

How are we able to image the brain using different MRI techniques?

As a consequence of recent developments, the diffusion MRI (DTI) technique has become an effective probe to qualitatively and quantitatively characterize brain tissue microstructure, white matter tract anatomy and the structural connectivity of developing human brain. T1 weighted and T2 weighted imaging, relaxometry MRI and MTI have provided other options to image the developing brain.

We distinguish different types of MRI techniques that we can use to image the brain: diffusion MRI, diffusion tensor imaging, diffusion MRI-based tractography, T1 and T2 relaxometry and approaches based on magnetization transfer.

• In the human brain, diffusion of water molecules most of the time occurs along the axons. Diffusion MRI (dMRI) is a non-invasive imaging technique that provides a unique opportunity to measure the diffusional characteristics of the human brain. It can be particularly be interesting to use in cases where the contrast from other imaging methods is not sensitive enough to resolve the boundaries between brain tissues. The diffusion sensitised signal is calculated using the formula S = S₀exp (-bD), in which D is the diffusion coefficient with units of mm2/s and S and S₀ are the diffusion sensitized and non-diffusion signals. By solving the equation of this formula in each voxel, the apparent diffusion coefficient (ADC) in biological tissues can be obtained.
• Diffusion tensor imaging (DTI) is able to display the magnitude, anisotropy and orientation of diffusion in the human brain in a 3D ellipsoid. Fractional anisotropy provides a measurement to characterise the shape of the 3D ellipsoid. In addition, axial diffusivity (AD), which provides the primary eigenvalue (λ1) of the tensor, quantifies the water diffusion parallel to the primary eigen-vector of the diffusion tensor. AD has been thought to describe the axonal integrity of the white matter fiber bundle. Radial diffusivity (RD) quantifies the magnitude of diffusion orthogonal to the principal diffusion direction. RD has been thought to reflect the extent of white matter myelination. Although AD and RD have been used to infer these microstructural changes, we need to take caution in interpretation.
• Diffusion MRI-based tractography can be used to reconstruct white matter pathways in a 3D form. In this way, the structural connections of the human brain can be mapped. More complex methods of dMRI tractography are even able to resolve complex fiber architecture in a given voxel. 
• The longitudinal relaxation time (T1) characterises the proton interactions with its environment. On the other hand, the transverse relaxation time (T2) characterises the interactions between protons. Both T1 and T2 are sensitive to local chemical and magnetic environment. Quite recently, it was proposed that computing the ratio between T1w and T2w image intensities can be used to map myelination differences across cortical areas. Nonetheless, the best approach to measure reliable differences across individuals or across brain regions within the same individual is to map T1 and T2 relaxation time constants quantitatively. Furthermore, maps of the fraction of water related to myelin, sometimes called the myelin water fraction (MWF), can be obtained using the T1 and T2 measurements as well.
• Other MR quantitative parameters relying on myelin amount have been developed and proposed in the recent years as well. The MTR technique, for example, informs about the ratio between free water and water with restricted motion bound to macromolecules.

How does the process of maturation of white matter take place from the middle fetal stage until the age of 2 years old?

Gray matter are metaphorically also thought of as information processing hubs, and white matter acts as a long-range communication and transmission systems. For several decades, the architecture of white matter has been imaged in histological studies of postmortem brains. The recent developments within the field of MRI techniques have led to the opportunity to image how certain connections emerge at the beginning of life and how the maturational trajectories of white matter tracts in typical development look like. The major white matter tracts in the human brain can be categorised into five functional categories: limbic, commissural, projection, association and brainstem tract groups. Using DTI studies, erogeneous emergence patterns of white matter across different tracts and tract groups were observed. Significant micro-structural changes of white matter tracts take place during the fetal stage. Inhomogeneous but organized myelination processes have been found to be possibly contributing to a reshuffled inter-tract correlation pattern and strengthening of the correlation of homologous tracts from neonates to children around puberty.

A variety of advanced dMRI techniques have also been used in the study of white matter maturation. T1 and T2 decrease with developmental processes, and specifically more strongly in white matter than in gray matter because of the myelination. T1 and T2 drops are particularly rapid over the two first years of life. MTR increases during white matter maturation, following an exponential time course. To better understand the cellular processes underlying white matter maturation in terms of axonal growth, organisation and myelination, biophysical models have been proposed. These models aim to link these cellular processes to the DTI-derived measurement changes during early brain development.

How does micro-structural maturation of gray matter take place from the middle fetal stage until the age of 2 years old?

Gray matter also develops rapidly in the fetal and infant stages. It has been shown in neurological research using structural MRI that the cortical gray matter volume in the human brain increases more than 4-fold in the short period of the 3rd trimester. Furthermore, gray matter volume increases 1.5-fold in the first two years of postnatal life. During cortical development, the majority of cortical neurons are generated near the cerebral ventricles and migrate towards the cortical surface along a radially arranged scaffolding of glial cells. In the fetal and preterm stage of development, the frontal lobe of the human brain appears to be relatively immature, as it displays less dendritic arborisation, synaptic formation and cellular differentiation. The maturation pattern of cortical FA and MD  is rather heterogeneous. This finding may be used to infer the complicated but precisely organised cellular and molecular processes during cortical maturation.

Marked microstructural changes are also observed in central gray nuclei throughout a young child's development. Microstructural changes that can be observed using the DTI technique suggest that membrane proliferation and fiber myelination processes are intense in the developing deep gray matter of the baby brain.

How does the baby brain develop connectivity?

Exciting developments in defining the developmental changes of whole-brain connectivity have been achieved by applying graph theory to diffusion tractography of white matter and resting state fMRI of gray matter. In network analysis of the structural connectome, the gray matter regions represent the “nodes” and the white matter connections between different nodes represent the “edges”. It is beyond the scope of this article to comprehensively review this rapidly evolving field.

What conclusions can be drawn?

On this basis of this research, several conclusions can be drawn:

• The maturational process of major white matter fiber bundles in most of the period from mid-fetal to 2-years-old is characterised by an increased FA and a decreased MD, whereas that of cortical gray matter is characterized by a decrease in both FA and MD.
• Another conclusion is that the maturation patterns of DTI-derived measurements reflect known cellular and molecular processes.
• Lastly, the early development of white and gray matter is spatiotemporally heterogeneous.

How can early childhood intervention contribute to children´s healthy development?

Children who lack social and emotional competence may experience adverse behavioral and academic consequences, and have a greater risk for long-term maladaptive health, wellbeing and vocational outcomes. Early childhood intervention aims to prevent that trajectory by fostering children´s social-emotional skills, attitudes, and behaviors. They try to encourage and nurture self-awareness, responsible decision making, social awareness, and self-management through lessons and child-centered teaching practices.

What is a response-to-intervention framework?

Response-to-intervention includes a three-tiered approach to identify and support children´s learning and behavioral needs through evidence-based intervention. It tries to align intervention to the needs of each child by increasing intensity from one tier to the next.

• The first tier offers universal curricula for all children. These programs provide a proactive and preventative approach that capitalizes on the preschool environment to promote social-emotional capabilities at the classroom scale.
• Tier two focuses on children that require more intensive support. It consists of targeted programs for children that are experiencing social, emotional, or behavioral challenges. This tier seeks to prevent escalation of more serious mental health concerns.
• Tier three interventions are presented to children requiring intensive and individualized assistance, usually children that display characteristics of mental health and developmental challenges.

How effective are Tier two intervention programs?

The effectiveness of Tier two programs in early learning settings for children experiencing social, emotional, or behavioral challenges was investigated in a meta-review. The following results were found:

• Several studies reported improvement in children´s social interactions, social skills, social-communicative behavior, and teach-child closeness following SEL intervention.
• Most interventions targeted children´s relationship skills through direct social skill instruction, teacher-child relationship building, play-based learning, or instructional practices. Early social skills have proven to be very important for children´s behavior.
• Children´s emotional and behavioral problems as a result of SEL intervention improved, but the results within and across studies were inconsistent. Children need time to rehearse and integrate newly learned behaviors. The development and maintenance of problematic behaviors and emotions are influenced by many factors, most importantly, the family context.

How does the human brain develop after birth?

The human brain changes dramatically in size and connectivity after birth. At age six, the brain will have reached about 90% of the adult volume. The growth of head circumference is largely driven by the growth of the underlying brain tissue.

What is occipitofrontal circumference?

Occipitofrontal circumference (OFC) refers to the largest circumference of the head (measure over the most prominent part on the back of the head and just above the eyebrows). OFC is a reliable predictor of brain volume in children younger than six. Clinicians can use OFC to detect brain growth abnormalities. Abnormal brain size in early postnatal years is often indicative of disorders of neurodevelopment.

What is microcephaly?

Microcephaly is a medical condition involving a shorter-than-normal head. Infants with primary microcephaly show small head circumference at birth and are often caused by genetic insults that disrupt neurogenesis. This is associated with intellectual disability at age seven. Infants with postnatal microcephaly show normal head circumference at birth, but then show subsequent attenuations in head circumference growth. This is often the result of defects in later-stage developmental mechanisms (for example with connectivity or gliogenesis). Postnatal microcephaly is associated with abnormal/absent language, social impairment, and epilepsy.

What is macrocephaly?

Macrocephaly is a condition in which head circumference is abnormally large. Postnatal macrocephaly refers to exaggerated head growth after birth, whereby infants are born with a normal head circumference, but then show abnormal head enlargement, often due to increased brain growth. This is associated with developmental delays of motor, language, and cognitive functions.

What are the potential biological mechanisms that cause postnatal brain growth?

Three biological mechanisms that underlie postnatal brain development are identified:

• Axonal and dendritic outgrowth increase during the second half of gestation. They form connections/synapses with other cells and give rise to early neural circuits. Dendrite elaboration accelerates during early childhood, followed by a gradual decline during late childhood and adolescence. Research indicates that altered axonal and dendrite formation are associated with intellectual and developmental disabilities.
• Synaptogenesis and experience-dependent synapse remodeling. Synapse formation begins prenatally, but the majority of synaptogenesis occurs in early childhood. It increases from birth until late childhood and is then followed by a gradual period of pruning that continues until early adulthood.
• Gliogenesis and myelination. The increase in number and size of glial cells are in large part responsible for early rapid and head growth. Myelination rapidly increases from six months to twenty-four months and gradually continues until late adolescence.

Which disorders are associated with abnormal postnatal brain growth?

Disorders may arise from an attenuation or an exaggeration of growth, and from monogenic of complex etiologies. Disorders with monogenic postnatal microcephalies are Angelman Syndrome, Rett Syndrome, and Christianson Syndrome. Disorders with monogenic postnatal macrocephalies are PTEN-related disorders, Tuberous Sclerosis Complex, and neurogenerative disorders.

What is the Angelman Syndrome?

The Angelman Syndrome is a postnatal microcephaly disorder that mainly affects the nervous system. Symptoms include a small head circumference, severe intellectual disability, developmental disability, speech problems, balance and movement problems, seizures, and sleep problems. Symptoms usually show after one year. The Angelman Syndrome arises from loss of expression of the maternally inherited allele of the imprinted ubiquitin protein ligase E3A gene.

What is the Rett Syndrome?

The Rett Syndrome is a progressive neurodevelopmental disorder characterized by impairments in language and coordination, repetitive movements, slower growth, difficulty walking, and a small head circumference. Other symptoms may be seizures, scoliosis, and sleeping problems. This disorder mainly affects females. Symptoms start to show after six to eighteen months. The majority of cases are the result from loss-of-function mutations in the X-linked gene MECP2. Loss of MECP2 leads to repression of several genes involved in brain development.

What is the Christianson Syndrome?

Christianson Syndrome is an X linked syndrome associated with intellectual disability, microcephaly, seizures, ataxia, and absent speech. There are also often common facial abnormalities, such as a long narrow face, large ears, open mouth, thick eyebrows, uncontrolled drooling, and abnormal eye movements. Christianson Syndrome is caused by a loss-of-function mutation in SLC9A&, which encodes for NHE6. NHE6 regulates endosomal lumen pH by allowing for electroneutral exchange of proton ions out of the endosome for monovalent cations into the endosome. Over-acidification of endosomal pH in absence of functional NHE6 may disrupt endosomal trafficking which is necessary for growth and neuronal development.

What are PTEN-related disorders?

Mutations in phosphatase and tensin homolog are implicated in various disorders with macrocephaly, including Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Proteus syndrome. These disorders have a predisposition of tumors and are collectively referred to as PHTS (meaning PTEN Hamartoma Tumor Syndrome). The brain overgrowth is likely due to abnormalities in proliferation and connectivity. The loss of PTEN protein or function disrupts neurodevelopmental events that occur prenatally (for example neurogenesis) and postnatally (for example dendritic growth and myelination).

What is Tuberous Sclerosis Complex?

Tuberous Sclerosis Complex causes non-cancerous tumors to grow in the brain and on other vital organs. Other symptoms may include seizures, intellectual disability, behavioral problems, skin abnormalities, kidney disease, and lung disease. It is caused by mutations in either TSC1 or TSC2. Tumors develop because of a disruption to the functional allele or other TSC protein that leads to uncontrolled cell growth.

What are neurodegenerative disorders?

Neurodegeneration refers to the progressive loss of structure or function of neurons. Many neurodegenerative disorders are due to neurometabolic disease related to synthesis, metabolism, transport, or storage of biochemical compounds. Many patients show microcephaly as a result of brain atrophy and cerebral white matter reduction.

What are Autism Spectrum Disorders?

Autism Spectrum Disorders refer to genetically and clinically heterogeneous disorders of atypical neurodevelopment characterized by impaired communication and social interactions and stereotyped behaviors. Some of the Autism Spectrum Disorders are associated with larger head circumference and brain volume. There are associations with defects in postnatal pruning, hyperactivated mTOR, and impaired autophagy.

What is schizophrenia and how is it related to brain development?

Schizophrenia is characterized by continuous or relapsing episodes of psychosis. It may arise in part from abnormal brain growth that begins years before symptom onset. MRI studies show reduced brain and gray matter volume, increased extracerebral spinal fluid, exaggerated typical back-to-front gray matter loss (predominantly in the prefrontal and temporal cortices).

What are the three most commonly used neuroimaging techniques?

• Electroencephalography (EEG) is a non-invasive method of measuring direct electrical activity in the brain. It is useful in researching the neural underpinnings of cognitive functions. It provides information about the size and frequency of a neuronal signal with high resolution, providing information about functional connectivity between brain regions during cognitive tasks.
• fMRI records the blood-oxygen-level-dependent response that occurs during neuronal firing. It has very good spatial resolution that enables researchers to produce images of spatially localized brain activation.
• fNIRS involves placing a cap containing sources and detectors of near-infrared light on the participant´s head. The system then records changes in light absorption levels between sources and detectors. fNIRS measures changes in concentration of oxygenated and deoxygenated haemoglobin in localized brain regions in response to a stimulus. Neuronal activity is signaled by an increase in oxygenated haemoglobin and a decrease in deoxyhaemoglobin.

What different models of executive function exist?

• According to the unity-diversity model, executive function is a hierarchical construct consisting of a domain-general unitary entity and three dissociable components, namely updating working memory, shifting, and inhibition. These elements are thought to be mediated by a fronto-parietal network.
• According to factor analytic work, there is a common executive function factor that represents the unity of the three core executive function abilities. The diversity of executive function exists in the factors that are specific to each component.
• The adaptive neural coding framework claims that executive function is a unitary, domain-general construct. This function recruits the same specialized frontal pathway in different ways depending on the task demands for a range of challenging cognitive tasks.
• The developmental model of executive function looks at changes observed in the structure of executive function and the underlying neural correlates during childhood and adolescence. The structure of executive function changes across development, from one that is largely unified and recruits a common neural network in early-to-middle childhood, to one that involves more diverse components that each recreuit specific neural networks.

What is working memory?

Working memory refers to a limited capacity cognitive system that enables the temporary storage and manipulation of information. The dorsolaterale prefrontal cortex (DL-PFC) is important in working memory development. Recent research has shown that also regions beyond the DL-PFC are important, as well as the connections between these areas.

What is inhibitory control?

Inhibitory control refers to the process of preventing an automatic response in order to achieve a behavioral or cognitive goal. Inhibitory control begins to develop towards the end of the first year of life, rapidly improving during the toddler and preschool years. It increases steadily throughout middle childhood, and reaches adult levels in early adolescence. The DL-PFC is activated in inhibitory control, but activation of the DL-PFC reduces with development. Also, during inhibitory control, there is parietal activation and striatum involvement.

How does the prefrontal cortex develop?

The prefrontal cortex is one of the last brain regions to fully mature. PFC maturation consists of both progressive (myelination, synaptogenesis, neuron proliferation) and regressive (cell death, loss in grey matter, synaptic pruning) changes. Increases in cortical volume, synapses and dendritic trees serve to facilitate information processing by forming connections between the prefrontal cortex and other cortical areas. Cortical thickness and volume develop following an inverted U-shaped trajectory, increasing in childhood and then declining during early adulthood.

What developmental changes in the prefrontal cortex underlie cognitive performance?

Research on direct links between structural prefrontal cortex development and cognitive performance is still limited, but the following results have been found:

• The structural integrity of the corpus callosum and white matter tracts that connect the prefrontal cortex to other brain regions during infancy are predictive of executive function in later childhood.
• Myelination allows for rapid and syncronised information processing that is required for many cognitive functions, including aspects of executive function.
• Performance improvements on executive function tasks indirectly parallel the structural changes in grey matter and are directly associated with the structural changes in white matter that occur in the same fronto-parietal cortices that are recruited during executive function task performance.
• Structural maturation of fronto-parietal regions is directly telated to the development of working memory (improvement in working memory was related to cortical volume reduction in the lateral prefrontal cortex and in the posterior parietal cortex).

What is the role of prefrontal dopamine during executive function development?

Prefrontal dopamine plays an important role in the development of executive functioning. Research has shown that the lack of prefrontal dopamine in children resulted in a selective deficit in tasks involving working memory and inhibition. Gene methylation, the silencing of a gene, also reflect the potential impact of dopaminergic genes on the prefrontal cortex during development. Gene mythelation falls under the umbrella-term of epigenetics. Epigenetic encompass changes in gene expression caused by biological mechanisms other than the DNA sequence itself. Environmental influences during post-natal development have an impact on methylation patterns, which can cause differences in psychological and behavioral outcomes.

What is frontal connectivity?

The prefrontal cortex develops rich connections within itself and with other cortical, subcortical and limbic brain regions, which together form a system that sub-serves executive function. Functional connectivity between the frontal and parietal cortices mediates early executive function development. Developmental improvements in executive function performance are partially due to functional integration via connectivity.

What is the refinement process of the prefrontal cortex?

Research indicated that with age there is a shift from global to local activation in the prefrontal cortex during executive function tasks. This shift may reflect the increased efficiency of the developing brain and the growing functionality of sub-regions of the prefrontal cortex for executive function. Mature executive function depends on the focalization of activity to brain regions directly linked to the related cognitive function, as well as decreased activity in supplementary brain regions.

What is the difference between effortful control and executive function?

Effortful control refers to the deliberate control of behavior and attention, which may be stimulus-driven or adult-directed. Executive function denotes a more independent, flexible, and goal-directed response to novel situations. The transition from effortful control to executive function is gradual and appears to occur over the course of the third year of life.

Why is it difficult to measure executive function in pre-schoolers?

It is difficult to establish ´pure´ measures of executive function in pre-schoolers, because their executive function is still developing, as well as their social, motor, and language skills. EF tasks require verbal comprehension and toddlers may misunderstand the requirements. Additionally, by taxing their verbal comprehension, an additional cognitive load is placed on the children, way may influence performance.

How does control of attention in infants develop?

Infants have selective attention from the first day of life, and during the first year they learn to direct and sustain that selectivity. This control of attention begins to emerge as early as four months, and undergoes a big transition around nine months, from which point individual differences in control of attention show moderate concurrent correlation and some predictive validity to measures of impulse control and cognitive flexibility within the third year of life.

What are causal and focused attention?

Focused attention, or selective sustained attention, is attention maintained on an object, event, or task for the purpose of learning more about it and/or reaching a goal. It is characterized by intense facial expression, a reduction of heart rate, minimal body movement, and a resistance to distracters. Causal attention on the other hand is characterized by engagement with stimuli in a repetitive and unfocused manner during which little to no information regarding the stimulus is processed.

What methods can be used for examining executive functioning in infants?

• The Laboratory Temperament Assessment Battery provides well-constructed tasks and coding schemes that can be used in the laboratory or at home to capture individual differences in focused attention.
• The Freeze-frame Task can be used to measure focused attention. In this task, an engaging central animation stimulus is displayed, but briefly frozen if the infant looks to peripheral distracters.
• Parental or caregiver report can be used to avoid context-specific fluctuations and can be used in many different contexts. Concerns with this approach are the potential bias due to the influence of social desirability, limited accuracy of memories of events, and unfamiliarity with the typical ranges of infant behavior. Parents or caregivers can use the Infant Behavior Questionnaire-Revised, the Early Childhood Behavior Questionnaire, or the Duration of Orienting scale.
• Effortful control can be measured by impulse control tasks and compliance tasks. Impulse control tasks involve suppressing a dominant response to reach for a desired item until permission has been granted. Compliance tasks require participants to engage in typical but mundane activities.
• Processing speed can be measured with two approaches: index processing through ocular reaction time (e.g. Gap-Overlap task and Visual Expectation Paradigm) and index processing through looking time to stimuli (e.g. visual recognition techniques).
• Response shifting can be measured with the A-not-B task.

What is the executive attention network?

Executive attention is one of three networks whereby the alerting system maintains sensitivity to incoming information (sustained attention), the orienting system drives the ability to respond to certain types of input and ignore others (selective attention) and to shift between targets. The executive attention network exerts top-down volitional control and recruits resources that are necessary for goal-directed behavior, conflict resolution, and error detection.

What are temperament, reactivity, and self-regulation?

Temperament is defined as individual differences in reactivity and self-regulation. Reactivity refers to an individual´s response to a stimulus change or alteration in the environment, which is manifested in changes in behavior and/or the physiological systems. Self-regulation refers to the set of processes used to modulate this reactivity. Individual differences in self-regulation emerge at eight months of age and have predictive validity to later executive function from the second year of life. Individual differences in self-regulation emerge in interaction with biologically-driven differences in reactivity and sex, and that relationship can be moderated by environmental factors such as parenting.

What is the difference between hot and cool executive function?

Hot tasks are those for which a proximal extrinsic reward or punishment for performance is included. Think of impulse control tasks which call for suppressing an emotionally-charged response to a desirable object. Cool tasks involve more abstract problems in which no extrinsic motivator for performance is included. Think of the selective application of a rule. Problem solving usually involves an interactive relationship between hot and cool executive function, as a rapid emotional response informs a simple approach or avoid response, which is then monitored and refined if necessary on the basis of more abstract if-then rules.

What is processing speed?

Processing speed entails both rapid assimilation of sensory input and effective encoding strategy. Processing speed accounts for much of the variability in performance of executive function tasks and is related to common executive function, updating, and shifting. Individual difference in processing speed show in early infancy and have predictive validity from five months. Infants who make shorter glances to new stimuli both process information quicker and encode global features rather than local features.

How does cognitive flexibility develop?

Cognitive flexibility goes through overlapping stages of improvement in maintaining task set, updating task set, shifting task set, and resolving conflict within or between task sets. By the end of the third year of life, each of the core elements of cognitive flexibility are present. The ability to combine and control these abilities continue to develop slowly from age three.

What is shifting?

Shifting refers to the ability of changing response behavior from using one rule to using another rule. Switch costs are task specific: tasks that demand more intensive control efforts, for example because they require an action that is not yet well rehearsed, are more difficult to suppress or shift away from. Task-specific switch costs have been explained by Parallel Distributed Processing and the Dynamic Field Theory.

What do Parallel Distributed Processing and Dynamic Field Theory in common when explaining task-specific switch costs?

Both models prioritize the importance of the memory trace in perseverative responses and state that inhibitory control in response shifting tasks is itself a behavioral product of working memory. A strong representation of the required actions for the tasks leads to execution of the action. A weak representation will enable a pre-potent response to win. This is why a U-shaped pattern of development is often observed in set shifting performance. Perseveration can only take place once the infant has developed a skill sufficiently enough to create a strong memory trace of that skill performance.

What is working memory?

Working memory is a cognitive system with a limited capacity that can hold information temporarily. It is a multi-componential system requiring the integration of domain-specific short-term memory and domain-general working memory capacity.

What is working memory capacity?

Working memory capacity refers to the maintenance or activation of information in the presence of interference or response competition. It has both an activation mechanism (organizing the holding in mind of the task goal and relevant sensory input with short term memory) and an inhibitory mechanism (inhibiting all competing information and processing).

What is early life stress?

Early life stress (ELS) is the result of adversities that produce frequent or chronic activation of stress-responsive physiological systems. These adversities deprive infants and children of the social and physical care that they need, cause homeostasis, provoke fear and anxiety, and dysregulate the function of the stress system itself. The most common forms of ELS are characterized by an accumulation of adversity. For example, poverty is a chronic, multi-dimensional stressor, and maltreated children typically experience multiple types of abuse.

What is the effect of early life stress on emotion processing?

Research shows differences in emotion processing after experiencing early life stress. There are interesting results with regards to brain function. Increased amygdala activation to emotional contexts appears to be beneficial following early life stress. And activation in prefrontal and striatal regions differ based on the type of adversity experienced.

What is the effect of early life stress on reward processing?

Differences in reward sensitivity have been observed following early life stress. There are differences between the type of ELS experienced and neural activation in the context of reward. In rewarding contexts neural activation is more consistent in maltreated and post-institutionalized individuals, while impoverished individuals show different patterns of activity. It is as of yet unclear whether altered reward sensitivity is protective and reduces the likelihood of risky behavior, or if it is a risk and leading individuals to seek larger rewards.

What is functional connectivity?

Functional connectivity refers to the connectivity between brain regions that share functional properties. In ELS literature, two main approaches have been used to investigate functional connectivity:

• Psychophysiological interaction (PPI) is used to understand the functional relationship between two regions in the context of a task. It examines the functional connectivity between two regions of interest whose activity has been convolved with task-related timing information.
• Seed-based resting-state functional connectivity (rsFC) looks at functional coherence between two regions of interest when the individual is not engaged in a task, the individual´s resting-state. In rsFC, a single region of interest is chosen as the “seed”. Then the time course of the seed´s functional activity is correlated with a set of regions or all other regions of the brain. Correlations with greater magnitude are interpreted as being more functionally connected.

What are the main findings from investigations of ELS and functional connectivity in the emotion processing system?

The main findings can be organized by ELS type:

• Poverty. Lower income-to-needs ratio is associated with diminished amygdala-prefrontal cortex connectivity. Individuals with lower family income during childhood show different patterns of frontolimbic connectivity when viewing aversive images or emotional faces, possibly causing altered emotion processing.
• Maltreatment. Maltreated individuals display lower amygdala- and hippocampus-prefrontal cortex connectivity, and lower amygdala-prefrontal cortex connectivity. These connectivity patterns are associated with poorer context memory and conflict regulation. Stronger amygdala-prefrontal cortex connectivity predicts more adaptive functioning regardless of maltreatment history. This means that high functioning individuals with a history of ELS may exhibit a compensatory neural phenotype that aids in adaptive functioning later in life, supporting the notion that adaptation may occur during the transition from adolescence into adulthood.
• Institutional care. Previously institutionalized children show more mature negative amygdala-mPFC coupling during emotion-matching, and they show significant amygdala- and hippocampus-PFC connectivity during aversive learning. The relationship between striatum-mPFC connectivity and social problems was moderated by age, in the way that functional connectivity was more likely to predict social problems in adolescents compared to children, highlighting the importance of investigating developmental trajectories after ELS.

In what sense are humans a social species?

Humans are a social species. Sociality is evolutionarily related to allostasis. Allostasis refers to the ongoing adjustment of an individual’s internal milieu that is necessary for survival, growth and reproduction. Social animals gradually learn to regulate their own and others’ allostasis using social communication. The literature indicates that across different species, higher allostatic demands are associated with more complex sociality. A caregiver’s allostatic support is rewarding, which makes social interactions a strong reinforcement for youngsters. With repeated care, the infant gradually builds an internal model of the caregiver. As the experience with the caregiver is repeatedly associated with a vigorous reward, it is hypothesized that the internal model of the caregiver is acquired as rewarding, which promotes infant attachment and motivation towards social interactions. 

It is proposed that neural systems that support human social behaviours overlap with those supporting allostasis. The neural circuitry that is needed for social affiliation is not evident in newborns, and develops throughout childhood. It is proposed that this potentiates a child's susceptibility to environmental input. Brain development and social development may be two manifestations of the same phenomenon: namely that of becoming social experts.

What do we mean when we talk about 'the social brain'?

The salience and default mode networks of the brain together make up an integrated network for implementing allostasis. The core intrinsic networks and hubs, specifically those in the default mode and salience networks, have been repeatedly demonstrated to participate in social brain processing. Examples of processes that can be described as social brain processing are maternal bonding, social cognition and social network size. These brain processes impaired in patients with social deficits such as in autistic spectrum disorder (ASD). Evidence from human neuroimaging studies suggests that there is an overlap between the neural system that supports social behaviours and the one that supports allostasis.

How does the brain develop throughout the life course of humans?

Human brain development is a protracted process that starts in utero and lasts for up to 25 years postnatal. The myelination of the long-distance axon tracts that allow for the fast, efficient information transfer throughout the networks of the brain, develops for the most part after birth. In general, sensory and motor-control networks become synchronized early in life and even during the prenatal period. However, major nodes of the default mode network continue to develop until young adulthood.

Research has established that provision of early life care shapes brain anatomy. Early social care also appears to determine the behavioural phenotype of the off-spring. Variation in maternal behaviour impacts children’s social development. It is hypothesised that infants will show facilitated network development when their allostatic needs are sensitively regulated. This hypothesis is supported by literature demonstrating that child development is optimized and even accelerated where provision of parental care is sensitively attuned to the infant needs.

What alternative framework for the social development of children is proposed?

A key feature of the predictive coding model is the interaction between the forward and backward flow of information: The backward flow delivers predictions while the forward flow computes the residual errors between prediction and sensory inputs. In early life as infants’ sensory pathways become intact, without sufficient sensory experience to form valid predictive models, most sensory input is considered ‘prediction error’, simply because the brain cannot predict it. Of special importance for the development of sociality is neural prediction within the interoceptive system, which is the sensory consequence of allostasis. A recent comparative study supports the importance of maternal care predictability by demonstrating that when infants can predict maternal sensory input, they can develop optimally.

With development, it is hypothesised that as top-down predictive models gradually govern infants’ experience, infants’ allostasis and allostatic independence will exponentially increase. This process might involve a gradual decrease in the salience of interoceptive prediction errors. It is also hypothesised that infants’ experience mostly includes bottom-up information, or prediction errors.

The amygdala, nucleus accumbens and hypothalamus are considered key regions in social processing. They also have a key role in allostasis regulation and are thought to compute prediction error and motivate behaviour. It is hypothesized that these regions’ involvement in social processing reflects an underlying process of preparing the organism for upcoming changes in allostasis.

In what way is the brain a conceptual processing system?

The mental representations of categories in the brain are referred to as concepts. It has been proposed that when the brain assembles populations of predictions, it is constructing concepts. Every event of new learning is categorised into a concept.

The first step in social development is acquisition of rudimentary social concepts. During early infancy, the infant gains experience interacting with the caretaker, and most interactions will be implicitly or explicitly aimed towards allostasis regulation. Through social regulation of allostasis, a child experientially acquires not only social concepts but also social competencies. One of the basic social competencies infants gain is synchrony. Bio-behavioural synchrony is an important aspect of mother–infant attachment, and has been shown to be important for shaping optimal developmental outcomes of physiological regulation, executive functions and social aptitude. Starting from gestation, a mother controls her foetus’s allostasis via mother–foetus physiological synchronization processes, such as synchronising heart rates and body temperature. 

In what way does culture influence social development?

Infants learn conceptual knowledge by synchronizing their attention with others. It is hypothesised that stimuli with a higher predictive value for allostasis will be learned quicker than stimuli with lower impact on allostasis. During development, infants learn social concepts and skills to prepare for allostatic needs, as caretakers introduce all the culturally relevant concepts using language. In addition to social learning, allostasis-driven learning can also shape other human features such as cognition, emotion and culture. Emotion and social concepts are environmentally constructed in each culture, and transferred between generations in social dyads during early life social training.

How does neural development of the social brain take place?

The neural trajectories of social development are not yet well-understood in neurological research. Of specific interest to social cognition is the temporal contingency between the developmental trajectories of the default mode network and of cognitive abilities such as conceptualization. The default mode network is believed to construct mental representations of concepts, including complex representations about other people’s minds. most of the core nodes of the default mode network become synchronized by six months of age. The grey matter volumes as well as functional and structural connectivity in the default mode network continue to develop during childhood, reaching full maturity in late adolescence.

Social care controls social and cognitive development via maturation of whole-brain neural networks. Parental care, which is consistently reinforced by allostasis, is necessary for the infant to build and refine a multisensory mental representation of concepts. Early life is a critical window for social learning due to the acute nature of the social dependency. The potentially crucial role of social experience during infancy in shaping brain and social development suggests that social animals do not necessarily rely on a predetermined specialized brain system to support affiliation. Instead, domain-general neural systems implement a conceptual system to regulate allostasis, and that underlies social behaviour.

Through social interactions, humans learn to link those abstract concepts to their allostasis to survive and prosper in their culture. This can potentially explain how beyond the immediate dyadic bond with the caregiver, extended social effects, including social class or economic status, may carry powerful effects on child development and even brain development.

What is affective empathy?

Affective empathy is a term for having concern for others, an emotional response consisting of tender feelings on behalf of a distressed other. It is often accompanied by attempts to cognitively comprehend the other´s state and can motivate prosocial action to alleviate the other´s distress. Empathy is the ability to feel what another is feeling. It is thought to result from overlap in brain circuits. Exposure to another´s emotion activates some of the same neural mechanisms involved when the self experiences that emotion.

What is self-distress?

When empathy is evoked by another´s distress, it can give rise to concern if the person remains focused on the other in distress. If the observer becomes overly aroused or distraught, the focus of concern can shift from the other to the self, which results in self-distress.

What is Hoffman´s stage theory of early empathy development?

This theory posits that infants are born with the capacity for empathic distress but cannot experience empathic concern until the second year of life. According to the theory, young infants lack awareness of the self as a separate physical entity from others and cannot distinguish between another person´s distress and their own. This confusion of distress states leads the infant to respond with empathic distress that is self-focused and to seek comfort for the self.

What criticism can be given to Hoffman´s theory?

Three aspects of the theory can be commented on:

• The assumption that young infants cannot distinguish between the self and others is inconsistent with research on young infant´s implicit ability to differentiate between the self and others. A basic, prereflective form of self-knowledge that is present from the beginning of life is sufficient for experiencing concern for others. This sense of self is based on the infant´s subjective experience of his or her own sensory perception and self-generated actions. Parts of the neural network do not overlap when processing similar experiences of self and others.
• The suggestion that young infants are incapable of empathic concern is not supported by empirical research. Moderate levels of affective and cognitive empathy were already present at eight and ten months, highlighting the importance of distinguishing between sybtypes of empathy.
• The idea that self-distress occurs because infants confuse the other´s distress as their own neglects the role of emotion regulation.

What is the bodily-self?

The bodily-self is a certitude which supports the ability to perceive our body as separate from other entities and provides the basis of self-perception. It involves neural representation, modulation of physiological homeostasis, and perception of body ownership. Information about the bodily-self depends on exteroceptive signals (somatosensory, visual, vestibular) and interoceptive signals (pain, hunger, itch, etc.). The information from these signals is integrated into the bodily-self representation. The processing of information from the body begins during the first year of life and possibly starts in-utero. 

How does the bodily-self develop during infancy?

The formation of the bodily-self is driven and progressively refined by learning about sensorimotor contingencies via interactions between brain-body-environment and self-generated actions. During infancy, the bodily-self is not only dependent on inherited neuro-maturational processes, but also upon relational experiences of body-to-body-interactions. From birth, an infant is engaged in body-to-body interactions with their mother. These interactions support bio-behavioral synchrony, which is the coordination of biological and behavioral signals during moments of social contact, and support the infant´s bodily-self perception

What is the importance of maternal touch for the infants development and development of the infants bodily-self?

Tactile interactions between parent and infant play a central role in the developing social, emotional, and physical needs of the infant. Touch is a multidimensional and dynamic system and has a unique role on perception of body ownership. Newborns are able to detect multisensory integration of body-related information both for the temporal and spatial properties of visual-tactile stimulation. Touch can enhance the early subjective feelings of body ownership and support multisensory integration, which improves and becomes increasingly more specialized with experience. Interpersonal tactile stimulation can integrate information between modalities and support the development of bodily self-perceptions in the infant.

What is interoception?

Interoception can be defined as the sense of the internal state of the body, and generally refers to the ability to perceive physiological changes, especially from internal organs such as the heart, lungs, and skin. Interoception plays a role in the development of perception, higher-order cognitive processes and affect. It is also associated with the ability to recognize emotion and contributes to the perception of the self.

How is early infancy interoception affected by interpersonal exchanges?

Interoceptive functioning may be associated with the quality of early interpersonal relationships. A mother´s interoceptive functioning can play a role in the early exchanges with the infant (mothers heartbeat, breathing, etc). Ventral-ventral parent-infant contact and other embodied interactions involve activation of the mother´s bodily sensations and possible modify the interoceptive sensitivity which supports moment-by-moment adaptation to interactive demands and the needs of the infant.

What is maternal sensitivity?

Maternal sensitivity is the ability to respond promptly and in an active, warm, appropriate, acceptant, and flexible way to the infant´s signals. Maternal sensitivity relies partially on perceptual processing of the infants body. A more refined maternal perception of the infant body cues is associated with higher maternal sensitivity.

What is parental embodied mentalization?

Parental embodied mentalization (PEM) is the parental capacity to comprehend the infant´s mental states from their body movement and adjust their own kinesthetic patterns accordingly. Parenting heavily relies on this nonverbal, bodily based and biological co-regulation. Greater PEM is associated with greater social competence, fewer behavioral problems, and greater cognitive functioning later in infancy.

What is the insula?

The insular cortex is a part of the brain that is believed to be involved with consciousness and the regulation of the body´s homeostasis. It has some important characteristics with regards to bodily self-perception and interoception:

• It is among the earliest cortical regions to develop and differentiate. The insular and somatosensory cortices are functional at very early stages of postnatal life.
• Insula neurons have a specific cytoarchitecture with Von Economo neurons, which are implicated in body self-perception.
• The insular cortex is strongly involved in the regulation of homeostasis, in the elaboration of interoceptive inputs, and in somatosensory perception with respect to pleasant tactile stimulations.

What are C-tactile afferents?

When we are touched, there is a specialized sub-modality of touch sensing and processing its affective properties. The dual-touch system consists of two parallel neural pathways, one for the affective touch (with the CT neurons) and one subserving discriminate touch. C-tactile (CT) neurons are a class of neurons that innervate the human skin. They are mechanosensitive unmyelinated C-fibers that respond optimally to the gentle caressing touch that are typical of nurturing care. They project primarily to the dorsal posterior insula and to brain networks involved in social perception processing. The preferred stimulus for CTs respond to specific velocities, forces and temperatures that are experienced by an infant during skin-to-skin nurturing care.

What is the Mutual Regulation Model?

According to the Mutual Regulation Model (MRM), mothers and infants (or caregivers and children) are linked subsystems of a dyadic system and each of them regulate disorganization and its costs by a bidirectional process of behavioral signaling and receiving. The model suggests that in typical interactions, mothers and their infants fluctuate between attuned and misattuned states and recovery attunement states by a process called reparation.

What is embodied reparation?

Embodied reparation describes the process by which each partner modifies their own bodily states, making it possible to shift from bodily misattunement to bodily attunement. Frequent misattunements are also called interactive ruptures and happen most of the time during face-to-face interactions between mother and infant. Dyadic reparation is critical for the development of infants´ self-regulatory capacities and scaffolding an implicit inner sense of self-efficacy in regulating the stress that is caused by socially challenging conditions.

What is the role of interoceptive experience in the embodied reparation process?

During misattunement, any discrepancy from the expected state of the body generates a physiological unbalance in the infant´s body. They start to show bodily, behavioral, and emotional signals which convey to the mother the infant´s state. The discrepancies can be minimized by performing actions to modify the bodily state of either the mother or the infant. Embodied reparation allows the infant to reduce the discrepancies within the interoceptive system using the mother´s body. Efficient embodied reparation allows the infant to recover a stable interoceptive experience, which in turn supports a positive experience of the own bodily-self.

What is the predictive processing perspective?

Predictive processing (PP) is a theory that proposes that successful navigation in the environment relies on the organism´s ability to optimize predictions about how one´s own behavior will affect proprioceptive experiences and how social and physical entities in the outer world behave. Sensory inputs provide highly incomplete and variable information about our complex environment which changes with behavioral navigation. The brain needs to improve inferences on the basis of sensory inputs and minimizing prediction errors. As prediction errors are reduced, the accuracy of internal predictive models is increased.

What is the hierarchical system in predictive processing?

According to the PP framework, the brain consists of lower and higher level areas that are organized in a hierarchical system. The different levels continuously communicate with one another. Predictions are formed at every level of the hierarchy. Mismatches between what is predicted and what is perceived are learning opportunities. The prediction errors are sent back to higher levels where the prediction was made, to update existing predictions and improve predictive models.

How can the predictive processing perspective help explain cognitive development in early infancy?

The PP perspective states that the main purpose of learning processes is to minimize prediction errors. As infants grow they need to interpret sensory information and translate their experience into appropriate behavioral responses in increasingly sophisticated ways. The PP framework may provide a perspective on several phenomena of infant development and learning. Phenomena that fit into the PP framework include infants´ statistical learning, motor learning, proprioperception, and the emerging representations and expectations about the physical world.

How can statistical learning in infants be viewed in a PP framework?

The brain constantly computes the probability of events in the environment on the basis of incoming sensory information. Statistical regularities of the environment cause the brain to form probabilistic models of its environment. There is evidence that infants generate such probabilistic models to represent statistical regularities in their environment. For example, infants learn to segment artificial language on the basis of statistical information such as transitional probabilities between elements.

How can infants´ motor learning be viewed in a PP framework?

Infants´ early motor behavior serves the generation of internal models and maps movements to consequences. These internal models can then be used to predict the consequences of their own actions as well as the goals of another person´s actions. This allows for imitation learning which seems to be at least partially fueled by infants´ drive to minimize prediction error. Infants adjust their predictive models about their novel abilities (such as walking and falling down) to interact with the environment on the basis of their prior sensory experiences.

What is a comparator model?

Infants focus their attention selectively on new events and objects with which they are not familiar. They lose interest in perceptual stimuli that they have repeatedly encountered (habituation) and their attention revives for new stimuli (dishabituation). When orienting toward a stimulus, the infant compares the sensory information with an existing neuronal representation. If the stimulus deviates from the existing representation, an orienting response leads to increased attention and the formation or update of a neuronal representation of the stimulus.

How can infants´ basic understanding about the world be viewed in a PP framework?

The main purpose of processing sensory information is not simply representing the external world, but the generation of appropriate behavioral responses by making inferences on the consequences of behavioral responses for sensory inputs. Infants learning may then be conceptualized as the formation and refinement of predictive models about animate and physical entities in relation to the infant´s own body movements and actions.

What are violation-of-expectation paradigms?

In violation-of-expectation (VOE) paradigms, infants´ orienting response is taken as an indicator of infants´ basic concepts about the environment. It is basically the idea that infants will show surprise when witnessing an impossible event. The PP perspective can offer an explanation for infants´ VOE responses. VOE responses indicate infants´ processing of prediction errors, which require them to refine prior predictions. Infants actively seek to reduce their uncertainties, which may be especially important for objects that don´t comply with their existing predictive models.

What correlations have been found that link socioeconomic inequality with brain structure?

• Socioeconomic status has been linked to cortical surface area, cortical thickness, and gray matter volume, especially in frontal and temporal regions which support the development of language, executive function, attention, memory, and emotion regulation.
• Family socioeconomic characteristics (parental education and family income) have been linked to children´s hippocampal volume, which is a structure that is important for learning and memory.
• Socioeconomic disadvantage has been linked with slower longitudinal growth of the hippocampus.
• Socioeconomic differences have been found in white matter microstructure, especially in areas that support executive functions, reading, and language.

What correlations have been found that link socioeconomic inequality with brain function?

• At six months of age, higher socioeconomic status was linked to greater high-frequency EEG power (which is associated with language development).
• At six months of age, family income and maternal education were associated with functional connectivity in the default mode network and the sensorimotor network.
• Lower family income has been linked to reduced connectivity between the hippocampus and amygdala and other cortical regions (for children).
• Connectivity partially explained the relationship between lower family income and negative mood and depression (for children).
• Functional brain development may be influenced by family level socioeconomic disadvantage as well as neighborhood socioeconomic disadvantage. Young people living in more advantaged neighborhood had a stronger positive association between age and functional connectivity than young people from more disadvantaged neighborhoods, in a pattern suggestive of faster functional brain development.

How do socioeconomic factors relate to the neural bases of language, emotion processing, and executive function?

• Inferior frontal gyrus lateralization of five-year-olds has been associated with maternal education.
• Socioeconomic differences have been linked to the neural response to learning new words.
• Neighborhood poverty has been associated with inferior frontal gyrus activation, supporting the idea that neighborhood disadvantage may account for extra variation in experience that is not caused by socioeconomic status of the family.
• Lower family income and lower socioeconomic status have been associated with increased neural activation to angry facial expressions in the fusiform gyrus, and increased amygdala responses to negative infant faces.

How can differences in experience be at least partially responsible for socioeconomic differences in brain and behavior?

Two mechanism are identified to help answer the questions whether socioeconomic status related differences in experiences and exposures lead to differences in outcomes, or whether outcome differences are the product of social selection, in which genetic underpinnings of academic achievement lead to differences in socioeconomic status:

• Cognitive/linguistic stimulation in the home may contribute to the emergence of socioeconomic disparities in the development of brain regions that contribute to higher-order language and cognitive skills.
• Exposure to chronic stress has serious effects on multiple brain and body systems, and is considered a mechanism linking socioeconomic disadvantage to neurodevelopmental differences.

What are the consequences of preterm birth?

Preterm birth is defined as a birth at less than 37 week's gestation. It is common and responsible for global child mortality. Researchers have become interested in the long-term outcomes of preterm birth and found some interesting links between preterm birth and cognitive and psychological outcomes. On average, children born preterm were found to experience poorer mental health and educational outcomes compared to their term-born peers. Pre-term birth is also associated with lower IQ scores. Difficulties with executive functioning, processing speed, verbal fluency, cognitive flexibility and working memory may underlie the poorer cognitive and academic performance of individuals who were born preterm. These cognitive outcomes appear to be rather stable over life. Especially problems with mathematics have been linked to preterm birth. Preterm birth also increases the likelihood of neurodevelopmental and certain mental health difficulties. Children born very preterm have, on average, poorer attention and more social- communication difficulties, peer problems, and internalising symptoms than their term-born peers. Links between preterm birth and depression during childhood are less clear. However, cohort study data for young adults born at extremely low birth-weights (<1,000 g) does not suggest an increased risk of psychiatric diagnoses in extremely low birth-weight children compared to matched normal birth-weight controls.

How does the brain of children who were born preterm develop?

For individuals born preterm, brain maturation outside of the uterine milieu, common medical complications, plus separation from parents due to hospitalisation may contribute to lasting changes in brain and autonomic development. The period between the current threshold of viability (22– 24 weeks) and term (40 weeks) is a stage when the brain is developing rapidly. In infants born preterm, this part of brain development in an atypical extra-uterine biological milieu. This leads to alterations in cortical development.

The impact of preterm birth on brain development may actually persists into adulthood. Studies have identified structural differences, including reduced cortical gyrification, alterations in network connectivity and changes in the trajectory of cerebral development. Daily skin-to-skin care, during which the infant is placed unclothed on the mother’s or father’s chest, improves child autonomic and circadian development, maternal attachment behaviour, and mother-infant synchrony compared to standard incubator care. At age 10, babies who received kangaroo care show bet- ter resilience to social and emotional stress, better sleep organisation and better executive function- ing compared to incubator care controls. Facilitating parental presence in the NICU may therefore promote better long-term outcomes for preterm babies. 

How does psychosocial development across the lifespan take place for children who were born preterm?

Psychosocial factors, from socioeconomic status to parenting, peer relationships, and bullying victimisation have a significant impact on long-term outcomes for preterm-born children. Parental sensitivity appears to be a key factor linked to positive developmental outcomes. Responsive and involved parenting of babies in the NICU has also been linked to higher IQ scores in adults born very preterm. Children born preterm appear to be particularly susceptible to certain forms of psychosocial adversity. The detrimental impact of low parental sensitivity appears to be greater in preterm compared to term-born children. Cohort study data also suggest that adults born extremely preterm are more susceptible than term born adults to mental health problems when they have experienced psychosocial adversity. Children born very or extremely preterm are at least three times as likely to be chronically bullied during childhood compared to their term-born counterparts. 

Difficulties with working memory in preterm-born children may lead to problems with mental arithmetic, and deficits across a range of executive functions have been shown to mediate the relationship between preterm birth and attainment at school. Cognitive and learning difficulties may form part of a cascade leading to poorer educational outcomes.

What recommendations for the future can we distinguish?

In conclusion, preterm birth appears to have a lasting impact on child educational and mental health outcomes. Parent-led organisations have started advocating for greater recognition of and research into the ongoing impact of preterm birth. More work is needed to identify fruitful interventions or support strategies to ensure that preterm-born children achieve their potential. Affecting nearly 15 million children born annually worldwide, preterm birth deserves more attention as a significant and potentially modifiable risk factor for poorer educational and mental health outcomes.

What is the role of the prefrontal cortex in executive function?

The prefrontal cortex (PFC) is involved in multiple forms of higher-order cognition, such as working memory, inhibitory control, conflict monitoring, and shifting between rule sets. These cognitive processes are referred to as executive functions. They allow the formation and execution of future-oriented plans as well as the inhibition of behaviors that do not serve those plans. It provides the foundation for decision-making and self-regulation.

How do environmental influences affect executive function and PFC development?

Environmental experiences shape developmental processes through:

• Experience-expectant processes. The neural circuits that process sensory information are sculpted by specific environmental inputs during sensitive periods in early development. Think of the sensory system development and the processing of light and sound.
• Experience-dependent processes. These reflect emergent connections between neuronal populations in a way that reflects each person´s unique environmental experiences. Think of long-term memory and home stimulus exposure.

Recent research indicates that there is unlikely to be one set of specific environmental experiences for optimal PFC development, but instead, that PFC development reflect adaptation to the child´s changing environment.

How is socioeconomic status thought to influence executive function development?

A variety of mechanisms operating at multiple levels of influence have been suggested. Children in poverty lack rules, structure, and routines, and their environments are more chaotic, unstable, and disorganized. This is thought to produce poor executive function. Also, exposure to high levels of stress has adverse effects on PFC function and executive function development. However, these explanations are limited in their ability to explain the types of environmental influences that are required for healthy PFC and executive function development.

How can cognitive stimulation be a mechanism linking socioeconomic status and executive function?

Cognitive stimulation is characterized by access to a complex environment with developmentally appropriate learning materials, a complex linguistic environment, a rich variety of experiences, and the presence of a caregiver who interacts with the child consistently and uses strategies that promote learning. This cognitive stimulation supports development of the feed-forward and feedback loops between sensory processing regions and the PFC, laying the groundwork for executive function development.

How do caregiver interactions and linguistic experience shape early PFC development?

Two pathways have been identified:

• Attention Regulation Pathway. In environments with limited caregiver interactions, children receive less guidance to attention regulation and have less experience involving competition between sensory inputs for attention that needs to be resolved. Combined with reduced access to sensory complexity this may result in limited organized feed-forward information from the ventral visual stream to the PFC.
• Linguistic Pathway. As children learn language, which facilitates object recognition and semantic knowledge, the PFC is continually engaged in conflict resolution and performing computations that are necessary for engagement in more complex forms of competition resolution that are considered in the domain of executive function.

How does socioeconomic status influence cognitive stimulation in a child’s household?

Environmental complexity varies as a function of socioeconomic status. Children growing up in low socioeconomic status households tend to experience lower levels of cognitive stimulation, including language exposure, environmental complexity, and caregiver interactions. Children growing up in higher socioeconomic status household tend to experience more cognitively stimulation environments, through enriching experiences (such as daytrips, museums), educational information (e.g. books), greater visual complexity of the home, and greater parental involvement in learning.

How can cognitive stimulation support executive function development?

Research shows that cognitive stimulation is associated with individual differences in working memory, cognitive flexibility, and inhibitory control. Caregiver involvement plays an important role in this relationship. Parental scaffolding and a rich linguistic environment support a child´s language ability and brain systems. Finally, cognitive stimulation has been linked to the structure and function of the ventral visual stream and the PFC. Specifically, a lack of cognitive stimulation appears to influence the cortical structure and function of the ventral visual stream regions, as well as the connectivity between those regions. 

How does socioeconomic status affect the ventral and dorsal visual streams?

Variation in environmental experience is associated with development of the ventral visual stream and associated functions. Socioeconomic status appears to influence ventral visual stream-dependent processes, but not dorsal visual stream dependent processes. Several research results support this idea:

• Socioeconomic status is positively associated with feature-based attention for color and object-based attention (ventral visual stream processes).
• Socioeconomic status is not associated with attention to motion (dorsal visual stream processes).
• Cognitive stimulation in early development predicts differences in cortical thickness in the PFC and ventral visual stream, but not the dorsal stream.

Does development of the ventral visual stream scaffold PFC development and executive function?

There is no direct evidence to support this relationship, but there are research results that are consistent with this hypothesis:

• Functional changes in the ventral visual stream across development play an important role in the development of higher order cognitive function among children.
• Structural maturation of the PFC is protracted and occipital, temporal, and parietal cortex maturation precede that of the PFC.

Earlier development of more posterior regions, including the ventral and dorsal visual streams, may help support the development of the PFC by feeding the PFC information about the environment.

What is the role of self-regulation in classroom behavior and learning?

Self-regulation has important implications for classroom behavior. Students with good self-regulation show fewer behavioral problems and positive teacher-student relationships (which propels learning). Self-regulation directly influences learning as it allows students to attend to important information, stay on task, remember instructions, and process necessary information.

Which neurocognitive processes are involved in self-regulation?

• Response inhibition: the suppression of actions that are inappropriate in a given context and interfere with goal-driven behavior.
• Voluntary attention: attention that is deliberately applied and controlled by the individual.
• Working memory: a cognitive system with a limited capacity that can hold information temporarily.

What is the role of response inhibition in self-regulation?

Response inhibition creates a delay period during which one can prepare a better response to the environmental demands. Deficits in inhibition are expressed in difficulty waiting, making careless mistakes, interrupting others, and impulsivity. Early inhibition problems fail to support, or even stand in the way of, children´s abilities to develop more skills over time. In school response inhibition is an important skill, for example, children should not run in the hallway, lower their voice, control impulsive behavior, and stop an incorrect response.

What is the role of attention in self-regulation?

Attentional control is very important for learning and the regulation of emotions and behavior. Selectivity is an important feature of attention, as attention does not only allow for selecting important information, but also for ignoring irrelevant information. Children with attention problems are easily distracted, appear disengaged and forgetful, require repeated directions, and make careless errors. They also tend to have less positive relationships with peers, and in combination with negative emotions are at higher risk for behavioral problems.

Which attentional networks can be identified?

Several attentional networks are identified that have differential effects on learning and behavior:

• Alerting network provides a necessary level of arousal and prepares students to learn.
• Orienting network directs attention to a stimulus. Involuntary orienting underlies distractibility and happens when there are strong cues from the environment. Voluntary orienting involves intentional focusing attention on an object or event which is relevant to one´s goals.
• Executive attention allows resolving the conflict between competing stimuli or actions by suppressing activity in areas of the brain which process a competing response.

What is the role of working memory in self-regulation?

Self-regulation is guided by internal representations including goals, rules, and plans. These internal representations are held in working memory. In school, working memory is necessary for following rules and directions, self-monitoring, and error correction. Working memory difficulties are expressed in difficulty following instructions and keeping conversations, forgetting details or procedures, reluctance to respond, and mind wandering.

How can interventions support self-regulation?

Self-regulation skills are responsive to intervention and can be improved. In the classroom, promoting self-regulation can help to increase learning time (by decreasing time spent on student´s problem behaviors) and promote full participation in learning (by students being less dependent on the environment). Self-regulation training should be given throughout the day and progress from less cognitively demanding tasks to tasks that require greater executive control. Interventions that can support self-regulation in early childhood education classroom are organization of the classroom environment, behavioral interventions, and instructional strategies.

How can organization of the classroom environment support self-regulation?

Effective classroom management, together with teacher´s emotional and instructional support, are associated with better self-regulation and academic engagement and less off-task behavior. Consistently enforced rules and routines allows for progression from regulation provided by teachers to self-regulation. Also, environmental distractions, such as noise and visual stimuli, should be managed to prevent interference that can reduce cognitive resources allocated for learning.

Which instructional strategies can promote self-regulation?

Different strategies can be used to promote self-regulation and these strategies can focus on different aspects of self-regulation:

• Strategies to build and actively maintain mental representations. The success of self-regulation depends on the quality of mental representations that guide task performance and behavior, their active maintenance in working memory, and their fidelity. Orienting basis of an action is an externally represented schema that guides students in the execution of their actions. Teachers should also have the goals and rules readily available, repeat them, and minimize irrelevant images and words.
• Strategies to support voluntary attention. Verbal attention coaching includes securing students´ attention before introducing a task and directing children´s attention to important information. Another strategy is On-Task in a Box, an intervention that combines self-monitoring with video modeling.
• Strategies to improve inhibition control. Intentionally inserting a delay can strengthen students´ ability to stop their incorrect behavioral responses. This can be done by using signals or verbal prompts to slow down, or using response cards instead of hand raising. Another strategy is having students reflect on task performance.

Which behavioral self-regulation interventions can promote self-regulation?

Different behavioral self-regulation interventions can be used to foster self-regulation skills in the classroom:

• Movement activities are associated with better motor inhibition, fewer behavioral problems, better behavioral regulation, more mature private speech, improved attention, and improved ability to stay on task.
• Game-based interventions. Movement-based games and cognitive games can improve motor inhibition, academic skills, knowledge of rules of conduct, verbal interference control, and delayed gratification, inhibition control, and working memory.
• Mindfulness requires sustained attention on a target object or activity and disengaging from distracters. It increases connectivity between attentional networks, resulting in more efficient and flexible allocation of attentional resources in the earlier stages of stimulus processing. It can be applied in different ways, such as mindfulness practice, mindful movement, and mindful meditation.

What is child maltreatment?

Child maltreatment is defined as any interaction or lack of interaction reasonably within the control of a parent or person in a position of caregiving responsibility, that does (potential) harm to the health of the child or physical, mental, moral, spiritual, or social development in the context of the society in which the child grows up. There are different types of maltreatment, including child sexual abuse, emotional abuse, physical abuse, neglect including physical neglect, emotional neglect, educational neglect, and witnessing family violence. There exists a high degree of comorbidity, co-occurrence, and poly-victimization in child maltreatment.

What are risk factors of child maltreatment?

• From an evolutionary perspective it can be argued that humans have an innate bias to promote one´s inclusive fitness which might be accompanied by abuse and infanticide of infants that compete with procreation of one´s own offspring. Also, the distribution of scarce resources to the infant with the best chances to survive may result in neglect of less fit and passive infants.
• Intergenerational transmission of maltreatment. Parents who have been the victims of child maltreatment are at heightened risk of maltreating their offspring.
• The spillover hypothesis states that marital quality is related to parent-child relationship quality. Interpersonal or intimate partner violence is predictive of child abuse.
• Psychological and neurodevelopmental factors. Parental characteristics and psychopathology may interfere with normative caretaking of young children. Think of low inhibitory control, a low threshold for aggression, major depressive disorder, or borderline personality disorder.
• New research indicates that children with certain neurodevelopmental features such as the presence of a learning disorder and/or an autism spectrum disorder may be at increased risk of maltreatment.
• Dysregulation of the neurophysiology of perpetrating parents would make them more liable to become abusive. If the balance between the sympathetic and parasympathetic systems is dysregulated, over- or underreactivity to stressful stimuli may result in neglect or harsh parenting.
• Single parenthood.
• Lack of social support.
• Low socioeconomic status.

What are protective factors of child maltreatment?

Protective factors may act as moderators of the association between risk factors and maltreatment. They may decrease the chances of child maltreatment even when risk factors are present. The following protective factors are identified:

• A social support network.
• Intervention.
• The presence of stable, safe, and nurturing relationships with intimate partners.
• High levels of maternal warmth.

What is the umbrella synthesis approach?

An umbrella synthesis involves the systematic collection and assessment of multiple meta-analyses published on a specific topic. The results from the meta-analyses are integrated and reviewed following a uniform approach to allow their comparison. This approach leads to comparable estimates of combined meta-analytic effect sizes, a systematic stratification of the evidence, an evaluation of the heterogeneity and potential biases, and sensitivity analyses to identify potential reporting biases.

Based on the umbrella synthesis, which antecedents of child maltreatment were identified?

Five categories of antecedents of child maltreatment were identified, namely parental experience of childhood maltreatment, parental personality characteristics, parental experience of intimate partner violence, parental baseline physiology and physiological reactivity, and socioeconomic status.

Which interventions can prevent or reduce child maltreatment risks?

Effective interventions appeared to be parenting programs involving parent training, such as Multisystemic Therapy for Child Abuse and Neglect, and parent-child interaction therapy. Nurse home visitations did not reduce reports of child maltreatment, but did lead to improvements in other domains such as health and cognitive developments. The umbrella synthesis revealed that certain interventions did not manage to affect the risk of child maltreatment, including interventions providing only support to the families, promoting healthy behaviors during pregnancy and early parenthood, establishing social support networks, and screening for developmental delay.

Why should more knowledge be gathered with regards to the antecedents of child maltreatment?

From the antecedents that have been shown to relate to child maltreatment, the underlying mechanisms are still unclear. Additionally, the antecedents that have been identified only account for a small percentage of the variance in child maltreatment. Finally, there is an absence of replicable evidence on potentially divergent precursors of different types of maltreatment.

Why should future research gather more information about the neurobiological antecedents of child maltreatment?

There exists no meta-analytic evidence on parental neural or genetic antecedents of child maltreatment. Also, intergenerational transmission of maltreatment may occur due to heritable characteristics of parent and child. If parents were maltreated themselves, prevention efforts can be helpful, independently of the genetics behind transmission.

What is recommended with regards to current and future interventions aimed at reducing and preventing child maltreatment?

More effective interventions need to be developed to protect more children and support more families. Currently, interventions are barely capable of preventing or decreasing child abuse and neglect in the next generation. Research into the effects of changing the socioeconomic conditions of families in low-resource environments is necessary. Limited social and material resources for families are one of the strongest correlated of elevated maltreatment risks. Universal health care, affordable education, paid parental leave, and more and better paid jobs may lead to less stress and better parental coping with challenging child behavior, which may lead to lower basal physiological levels and lower risks of maltreatment.

How can the vicious cycle of maltreatment and the failure to develop effective interventions be broken?

Two ways are recommended. Firstly, parents should be empowered to cope more sensitively with challenging child behavior and to set gentle but consistent limits to oppositional and coercive interactions. Secondly, attention should be paid to differential susceptibility. Differential susceptibility refers to the idea that some individuals are more open to environmental influences than others. The efficacy of intervention effects on child maltreatment may be hidden in susceptible subgroups of participants, which goes unnoticed now due to the evaluation of average effects across all parents involved.

According to differential susceptibility theory, what differentiates the more susceptible from the less susceptible individuals?

Differential susceptibility theory proposes three markers on the levels of genetic, stress regulatory, and temperamental makeup.

• Genetic markers have been found in genes involved in the dopaminergic and serotonergic system. The carriers of the dopamine receptor D4 7-repeat alleles seem to be open to the environment and this genotype may be embedded in larger dopamine-related genetic pathways or polygenetic susceptibility scores.
• Individuals may have a biological sensitivity to context, involving heightened stress and immune reactivity to negative stimuli in a chaotic and stressful environment.
• Individuals may differ in temperamental difficultness. Difficultness is broadly defined as encompassing negative emotionality, surgency, and effortful control. It predicts higher levels of internalizing and externalizing behavioral problems, as well as a heightened openness to the influence of change in the environment for the better.

How does differential susceptibility theory explain why there is not always intergenerational transmission of child maltreatment?

According to this theory, resilient individuals are characterized by a lower degree of susceptibility to the environment. Less susceptible individuals can rely on their constitutional resilience which is rooted in a less reactive temperament and neurobiological makeup. More susceptible individuals on the other hand must rely more on a supportive environment as a buffer against adversities. These individuals may do very well if they grow up in a warm and sensitive caregiving scaffold, highlighting the role of social context in resilience.

Why is it necessary to investigate the relationship between executive function deficits and preterm birth and/or low birth weight?

Preterm birth and low birth weight co-occur frequently. Many children born preterm are also born with a low birth weight and vice versa. These children are at high risk of adverse cognitive, academic, and behavioral outcomes. They often show impairments in executive functions, which play a crucial role in the onset of academic and behavioral problems.

Which three core executive functions were examined in the meta-analyses of Van Houdt et al. (2019)?

• Working memory is the ability to hold information in mind and actively manipulate this information. Visual-spatial working memory was examined using the Cambridge Neuropsychological Test Automated Battery Spatial Working Memory task. Verbal working memory was examined using the Digit Span Task and the Letter Number Sequencing task.
• Inhibition is the ability to deliberately inhibit a prepotent response or stop an ongoing response or suppress disruption by competing responses. Response inhibition was examined using the Go/No-Go task and the Test of Everyday Attention for Children Opposite Worlds task. Inference control was examined using the Test of Everyday Attention for Children Sky Search task.
• Cognitive flexibility is the ability to shift between multiple tasks or mental sets. This was examined using the Trail Making Test/Trails Preschool Revised.

Based on the meta-analyses, what results were found with regards to the relationship between preterm birth/low birth weight and executive functions?

Children born preterm/low birth weight scored lower on working memory and cognitive flexibility measures, as well as inhibition measures. There were no differences between these executive functions, meaning that they were all affected to a similar degree. In previous research, executive function deficits have been described to be proportional to decreasing gestational age, but those studies featured children at the extreme ends of the gestational age range. More research is necessary, specifically including children born extremely preterm.

Do executive function deficits in children born preterm/low birth weight represent a stable deficit?

Researchers are investigating whether or not executive function deficits in children born preterm or with low birth weight represent a stable deficit, meaning a deficit that increases during development, or a delay in maturation in which children catch up over time. In the current research, the difficulties appear to be stable and do not diminish as the children grow older. However, the children examined were no older than 14 years, and it´s possible that there may be catch up in executive functions after that age.

What is child maltreatment?

Child maltreatment refers to physical, sexual, and emotional abuse, and physical and emotional neglect, or a combination of these various types of trauma. It reflects an international consensus about what constitutes unacceptable childcare and the violation of children´s human rights. The etiology of child maltreatment is complex and multidimensional and involves factors associated with perpetrators, children, the nature of maltreatment, and the immediate and broader social, economic, and cultural context in which maltreatment occurs. It is associated with adverse outcomes across the lifespan in physical health, mental health, and psychosocial adjustment.

What causes a lack of scientific clarity linking child maltreatment to adverse outcomes?

The lack of scientific clarity is largely due to the scope and methodology of systematic reviews and meta-analyses. Some reviews focused on one type of maltreatment, others on a narrow range of outcomes. Few researches link together evidence on the effects of multiple forms of maltreatment on a wide range of outcomes.

What are the main findings of reviewing the scientific data on child maltreatment and adverse outcomes?

• Child maltreatment is associated with a wide range of physical health problems, such as a pro-inflammatory state associated with reduced immune system efficiency, underpinning many other physical health problems.
• Adult survivors of child maltreatment show abnormalities in brain structure and functioning, as well as the endocrine system, underlying mental health problems.
• Child maltreatment is associated with adverse psychosocial outcomes across the life span, such as difficulties in making and maintaining relationships, managing sexual and aggressive impulses, adjustment in school and work, and maintaining a satisfying quality of life.
• The occurrence of multiple forms of severe maltreatment are associated with more adverse outcomes.
• Specific forms of maltreatment seem to be associated with specific outcomes. For example, physical abuse is linked with aggressions, sexual abuse with sexuality problems, and emotional abuse with mental health problems.

What recommendations can be made for policy, practice, and research with regards to child maltreatment?

Several recommendations can be made:

• To prevent child maltreatment, child maltreatment prevention programs as well as community-wide parent training programs should be implemented.
• For survivors of child maltreatment, a universal trauma-informed approach to the provision of health care should be provided, as well as evidence-based group therapy.
• There is a need for more longitudinal studies on the psychosocial and physiological mechanisms that link maltreatment to adverse outcomes across the lifespan.

How is poverty related to negative mental health outcomes?

Poverty is marked by economic, social, and psychological challenges. It is associated with many different stressors and disadvantages, such as issues with household noise, structure, and organization, higher rates of community violence, exposure to teratogens, differences in cognitively stimulating experiences, and inferior perceptions of the self. Research has shown that exposure to poverty in childhood is associated with increases in externalizing and internalizing problems, and that the effects of child poverty persist into adulthood.

How can neuroscience be used to understand the mechanism relating poverty to negative mental health outcomes?

Nearly any form of psychopathology represents the integrated output of multiple underlying neural systems. As the brain is especially shaped by early life experiences, it ultimately determines behavioral and physiological responses over the course of the lifespan. Research points to the important role of self-regulation as a mediator between child poverty and psychopathology. Self-regulation is important for development and may aid in integratively organizing neural circuits central to its components, such as attentional focus and emotion regulation.

What is self-regulation?

Self-regulation can be defined as the ability to adaptively modulate one´s own cognitions, emotions, and actions for the purposes of goal-director behavior. It can be separated in two categories:

• Bottom-up mechanisms involve responses that are automatic and reactive. The two bottom-up facets that are identified (and their connected central neural hubs) are salience evaluation and interpretation (amygdala and ventral striatum), and stimulus generalization (hippocampus).
• Top-down processes refer to deliberate and controlled thoughts or actions that are used to problem-solve, resolve conflict, or prepare for an expected objective. The two top-down elements of self-regulation that are distinguished (and their connected central neural hubs) are executive attention (dorsal anterior cingulate cortex, dorsolaterale prefrontal cortex, insula), and response evaluation and emotion modulation (ventromedial prefrontal cortex and lateral prefrontal cortex).

What are common neuroscientific research methods?

Each measure has different strengths and limitations:

• Magnetic resonance imaging (MRI) produces spatially rich images of brain anatomy where the volumes of regions are measured. It does not provide information about brain activity. Regions may differ in volumes but be more or less active during a cognitive process.
• Diffusion-weighted imaging (DWI) is a type of MRI that probes structural connectivity in the brain through assessment of water diffusion in brain white matter. It does not measure brain functioning.
• Fractional anisotropy (FA) is a derived measure in DWI and describes the directionality of water diffusion and is modulated by microstructural properties of white matter, including fiber density, myelination, and axonal diameter. More diffuse white matter connections, lower axonal density, or reduced myelination may impede brain functioning.
• Electroencephalography (EEG) measures electrical activity on the head that is partially reflective of activity of neurons and the brain´s other basic machinery. It offers very precise temporal resolution, but poor spatial resolution.
• Functional MRI (fMRI) measures differences in blood oxygenation, which is highly correlated with actual neuronal activity. It offers high spatial resolution, but does not clarify the specific timing of the events occurring in the brain.

What is executive attention and how is it associated with childhood poverty?

Executive attention can be viewed as the broad, top-down ability to hold and use stable representations to guide behavior, while also adapting to and incorporating important incoming information. Two brain networks act relatively independently to produce top-down control, namely the fronto-parietal network and the cingulo-opercular network. Lower socioeconomic status has been associated with worse executive functioning, including differences in attention shifting, working memory, and inhibition. Young people living in poverty show structural differences in the fronto-parietal and cingulo-opercular attention networks.

What is value-based decision-making and how does it relate to childhood poverty?

Value-based decision-making is a method for making critical organizational decisions in an informed and timely manner. If a person decides to pursue a goal, they may consider both the perceived value and costs of the goal. These subjective elements determine the behaviors pursued. The ventro-medial prefrontal cortex (vmPFC) appears to be involved in value-based decision-making. Childhood poverty is found to be linked to smaller vmPFC volumes, and lower structural and functional connectivity between the vmPFC and other brain regions. This impairment may mean that disadvantaged youth may be less effective when making value-based decisions.

What is salience evaluation and interpretation?

Salience evaluation and interpretation refers to reward and vigilance processing. The subcortical structure ventral striatum (VS) is critical to incentive motivation. It displays higher activity depending on different dimensions of reward, including magnitude, effort, probability, and delay. Research has found an association between higher levels of VS activity during different reward paradigms and a preference for smaller immediate rewards. There is also evidence of alterations in functional connectivity in the broader circuit that the VS is nested in, which may connect to aberrant use of reward signals to guide behavior.

How is the hippocampus related to poverty?

The hippocampus plays an important role in consolidating information from short-term memory to long-term memory, which may impact self-regulation. Research has linked child poverty to deviations in the function of the hippocampus at all stages of development, particularly, young people from low socioeconomic background appear to have smaller hippocampal volumes. These differences may be due to the hypothalamic-pituitary-adrenal axis (HPA-axis) and cortisol. Sustained elevated HPA axis activity may cause dendritic remodeling and neuronal death in the hippocampus and other brain regions.

How can childhood poverty lead to behavioral differences in self-regulation and subsequent psychopathology?

Challenges common to poverty may cause alterations in top-down and/or bottom-up self-regulation behavioral processes. Deficits in self-regulation could lead to an unawareness of one´s own behavior and its consequences, difficulties resolving differences between one´s actual behavior and outcomes, and an inability to detect and anticipate negative outcomes. These challenges may contribute to the development and maintenance of psychopathology.

What is self-regulation?

Self-regulation is the capacity to guide one´s own goal-directed activities over time and across changing circumstances. It involves using cognitive processes to regulate behavior and emotional responses. It includes multiple distinct and overlapping mechanisms, such as effortful control, emotion management, focusing and shifting attention, and inhibiting and activating behavior. 

How does self-regulation develop during early childhood?

Between twelve and eighteen months children become capable of self-control. From then on, self-regulation develops exponentially, with rapid non-linear growth in the preschool years. Early self-regulatory processes provide a basis for a continually evolving framework. More advanced self-regulatory processes build on mechanisms that have developed earlier, and gradually create more sophisticated behavior as children mature. Well developed self-control in early childhood predicts positive outcomes later in life, including better health and academic outcomes.

Which factors influence the development of self-regulation?

Many factors are capable of influencing the development of self-regulation, such as temperament, genetics, and the general environment in which the child is growing up. Especially important are parental factors. Parenting is a key social mechanism in the intergenerational transmission of self-regulation. It can help children whose temperament or genetics are not in favor of healthy self-regulation development. Positive parenting strategies are associated with better child self-regulation, whereas negative parenting strategies are associated with weaker child self-regulation. Also, parental modeling of self-regulatory skills influences children´s self-regulatory skills.

Which parenting interventions can be used in infancy to promote early child self-regulation?

The difficulty with identifying specific interventions that promote early child self-regulation is that parenting interventions are generally not targeted at self-regulation skills specifically. However, some self-regulatory outcomes have been measured:

• An intervention targeting responsive caregiving for infants in foster care resulted in better infant biological self-regulatory skills and better executive functioning.
• Interventions targeting parents of premature infants focusing on early parenting skills resulted in enhanced toddler emotion regulation in stressful situations.
• Skin-to-skin contact between mother and infants improve self-regulatory skills in preterm infants.
• Interventions targeting the co-parenting relationship at the transition to parenthood led to improvements in one-year-old infants´ observed self-soothing behavior.

How can parents in the toddler and preschool period promote early child self-regulation?

Parent involvement, positive and proactive guidance, and low negativity are important in supporting young children´s self-regulation in de toddler and preschool period. Parents of preschool-age children can have a positive effect on self-regulation skills. Research has uncovered the following results:

• Positive associations between parent´s use of positive control and negative associations for parent´s negative control with children´s self-regulation.
• Parental guidance and limit setting that is provided in a positive and non-intrusive manner are parenting skills that support self-regulation in young children.
• Positive behavior management led to improvement in effortful control of preschool-age children with behavioral problems.

What are the effects of parenting interventions on child self-regulation among young school-aged children?

There have not been studies done to examine this link. However, some trials of multi-component programs that include a focus on parenting interventions suggest that such programs can improve child self-regulation skills (for example by practicing staying on-task, completing tasks, expressing and managing negative emotions appropriately). One research found that effects of the Fast Track program indicated that the important preventative effects of the intervention aimed at reducing delinquency and arrests in adolescence and early adulthood were mediated by growth in emotional and behavioral self-regulation skills and social competence during childhood.

What are institutions?

Institution refers to a publicly or privately managed and staffed collective living arrangement for children that is not family based. These include orphanages, children´s institutions, group homes, children´s villages, infant homes, and similar residential settings for children. The quality of these facilities varies greatly, depending among other factors on the extent of the training that staff receive, the rate of staff turnover, the quality of food, the child-to-caregiver ratio, and the standard of hygiene and health care.

Why are institutions often not capable of proving the necessary family environment for healthy child development?

Families are essential units which can usually provide children with the care, nurture, socialization, and protection required for healthy development. In institutions, care is often provided by teams of poorly paid staff, who often have little training and not enough time to provide a basic standard of care to the children. There is also a higher occurrence of peer and staff maltreatment of children. The social and cognitive aspects of institutional care are often of low quality and inconsistently delivered.

What is the Bucharest Early Intervention Project?

The Bucharest Early Intervention Project is the only study that used a randomized controlled design to study the benefits of deinstitutionalization. Some institutionalized children were randomly assigned to a high-quality foster care programme developed by the researchers. The other children were assigned to institutional care as usual. The study provides a test of the recuperative power of family life compared with continuing institutional care.

How did child care institutions arise?

The earliest reference to the institutionalization of children was in the year 787 in response to the problem of child abandonment. Over subsequent centuries, similar institutions were established in most major European cities and the colonies of Europe. Mortality in these settings was often high because of unsanitary conditions and poor nutrition. This instigated the transition from an institution-based to a family-based social welfare system. The number of children in institutions decreased and the number of children in foster care and adopted homes increased.

Which events caused a rise in the number of children in institutions?

Over time there have been several events that have caused the number of children in institutions to rise. For example, after the Russian Revolution in 1917 and World War 2 there were many displaced and abandoned children and not enough families that could offer fostering or adoption. Also, the HIV epidemic in the eighties in Africa caused a rise in the number of institutions. Finally, the one child policy in China, introduced in 1979, led to a substantial expansion of child institutionalization.

Why is it difficult to accurately estimate the number of institutionalized children?

Reliable data on the number of institutionalized children are difficult to collect because these numbers are not captured in household surveys or administrative data. Additionally, a high proportion of institutions in the world are not officially registered. The most recent estimate is around 6 million children, but this number is likely to have increased because of the HIV crisis, humanitarian emergencies, and the increased interest of private financial donors in funding the creation and operation of institutions.

Which factors may cause children to be institutionalized?

There are many different factors that can result in the entry of children into institutions, such as poverty, disability, parental mental health problems, or parental death. Cultural factors also play a role, for example in the case when children are born outside of marriage to young mothers in some societies. Child abuse within families may also play a role, though it is not often cited as the reason for institutionalization.

What is the difference between globally depriving institutions and psychosocially depriving institutions?

Globally depriving institutions refer to institutions where there are ten to thirty children per caregiver. Psychosocially depriving institutions refer to institutions where there are three to six children per caregiver. Most institutions are psychosocially depriving. These institutions often also have high staff turnover, employ staff with little training, have poor child-caregiver interactions, and often segregate children with health problems or disabilities. Especially in the early years of development, deficits in nutrition and hormonal growth suppression contribute to psychosocial growth problems in institutions.

How many children leave institutions and for what reasons?

Children can go to different caregiving environments after deinstitutionalization, including return to birth family or family networks, foster care, adoption, and ageing out into adult society. It is difficult to accurately estimate the number of deinstitutionalized children, because some countries reduce the number of institutions or reorganize them, no longer qualifying them as institutions. One major problem with promoting deinstitutionalization and closing institutions is that institutions often have a large number of local people who are dependent on the existence of the institution for employment. These people support the continuation of the facility.

What are the effects of institutionalization on child development?

Institutionalization is associated with substantial developmental delays and deviations, though there is a large variation in delays among the developmental domains.

• Institutionalization is strongly associated with delays in physical growth, cognitive development, brain development, and attention.
• The largest delays for physical growth and cognitive development emerge in infancy and early childhood.
• Attention problems tend to increase with age, possibly because executive attention develops later and deficits are difficult to detect in early childhood.
• Boys appear to have more delays than girls after institutionalization, but girls have more delays in physical health.
• Only a few children developed a secure attachment relationship with the closest caregiver in the institution. The proportion of dysregulated attachments is much higher in institutionalized children.

What are the effects of deinstitutionalization on child development?

Children show initial signs of rapid improvement following deinstitutionalization, though this accelerated development may represent a short-term catch-up at the expense of delayed development at a later developmental stage.

• Deinstitutionalization was followed by a catch-up in physical growth and cognitive development.
• There did not appear to be a recovery in children´s socioemotional problems after deinstitutionalization, but only few studies were analyzed.
• Children who have had extended deprivation can develop secure attachments with their new parents from adoption or foster placements, even after they have been exposed to severe deprivation.

Which contextual characteristics are associated with variations in the sequelae of institutional care?

A child´s response to institutionalization and deinstitutionalization will differ between individuals. Various contextual characteristics influence these responses:

• Pre-institutional context (the prenatal and postnatal risks that the child has been exposed to before entering institutionalization).
• The duration and timing of institutional care. Longer stays in the institution is related to larger developmental delays and deviations. Also, six to twenty-four months of age appears to be an especially sensitive period for the effects of institutional care.
• Quality of care.
• Post-institutional influences, including parent and family resources, quality of post-institutional care, and individual differences in parenting.

What is the difference between sensitive period and critical period?

Sensitive period refers to a time in development when individuals are especially sensitive to adverse exposures in a way that increased the risk of negative outcomes. These adverse exposures may be necessary to an adverse outcome to occur, but not everyone exposed is necessarily affected. Critical period refers to a time in development when exposure to specific experiences leads to inevitable and permanent negative outcomes. In these periods, the adverse exposures may not be necessary for adverse outcomes, but all children exposed to these adverse exposures will be affected.

Which child characteristics are associated with variations in the sequelae of institutional care?

Characteristics specific to the child may partially explain variations in the effects of institutionalization and deinstitutionalization. For example, genetic variations may affect the susceptibility of a child to both negative effects of institutionalized care and positive responses to placement in a supportive family. Also, the developmental status of a child at the time of their placement in a family after deinstitutionalization may influence the recovery trajectory of that child. The expectation is that the more ingrained the effects of deprivation are, the less amenable to recovery and the more persistent the problems may be.

In what way are empathy and prosociality related?

Empathy involves the vicarious experience of another person’s distress, which can precipitate prosocial acts of help. Both empathy and prosociality are fundamental to moral and social behavior. Children’s empathic concern for others and displays of prosocial behavior emerge by the second year of life. Research towards deficits in these processes to explain antisocial behaviour has focused on callous-unemotional (CU) behaviours.

How can callous-unemotional behaviours develop during childhood?

Callous-unemotional behaviours in childhood are characterised by low empathy, low guilt, uncaring about others and low emotional responsively. It has been established that CU behaviours assessed as young as age 3 predict future behaviour problems. CU behaviours are characterised by homotypic continuity, which means that they remain constant over development.

A large developmental literature has linked parenting to the development of empathy and prosocial behaviour. Warm parenting is thought to encourage and scaffold emotional expression and sensitivity, and increase the likelihood that children internalize parental messages about empathy and prosociality. Negative parent-child relationships appear to amplify the risk that the development of empathy and conscience could fail. Greater parental warmth predicts decreases in CU behaviours across the preschool period, whereas parental harshness at age 2 predicts increases in CU behaviours at ages 4. However, also broader negative contexts can undermine child socioemotional development via effects on parenting. At the same time, genetically-informed studies suggest at least moderate heritability of CU behaviors in early childhood. Parenting is critical to the development of early CU behaviours. CU behaviors develop through a complex interplay between genes and environment.

What are temperament precursors of early childhood CU behaviour?

Across several recent studies, early temperamental markers of CU behaviors have been identified. For example, children with CU behaviors show lower affection and eye contact with parents. Impairments in attending to, recognizing, and responding to interpersonal emotions as early as infancy may increase risk for CU behaviors. These impairments could contribute to deficits in the development of affective empathy. Empathy is commonly divided between emotionally resonating with the feelings of another, referred to as affective empathy, versus understanding the perspective of another, referred to as cognitive empathy. Evidence suggests that children high on CU behaviours have intact cognitive but impaired affective empathy both during the preschool period and in late-childhood.

In addition to emotional responsivity, a second temperament relevant for understanding CU behaviours is low fear. Early fearlessness confers low arousal to threat, which undermines learning about the consequences of behaviour, thus increasing risk for CU behaviours.

What interactions between person and context have an influence on the development of early CU behaviour?

Drawing together research on parenting and child temperament, studies suggest that interactions between child temperament and parenting are critical in the development of moral emotions. Inherited child characteristics interact with caregiving to shape the development of empathy and prosocial behaviour and that person-context fit may be particularly important in the development of prosocial behaviours. Child temperament interacts with parental caregiving to increase or buffer risk for CU behaviours.

What developmental model of early CU behaviour can be proposed?

Based on this literature, we propose that early CU behaviours arise in the context of inherited temperament risk for both low interpersonal emotional sensitivity and fearlessness. It is hypothesized that CU behaviours arise from the interaction of two heritable pathways:

1. Inherited low interpersonal emotional sensitivity sets the foundation for failure to develop affective empathy, operationalized via low emotional contagion in infancy, and fewer facial or verbal expressions of concern for others’ distress, low positive affect, and eye contact deficits from age 2 onwards.

2. Inherited fearlessness sets the foundation for a failure to develop behavioral inhibition to threat, including non-social threat and social threat, which lead to high approach, reward dominance, and difficulty learning from punishment.