Adolescence: Developmental, Clinical, and School Psychology – Lecture 3 (UNIVERSITY OF AMSTERDAM)

In adolescence, there are three main biological changes:

• Influx of pubertal hormones.
• Growth spurt.
• Change in circadian rhythm.

Adolescence is characterized by more advanced moral reasoning due to more advanced perspective taking and more risk and impulsive behaviour. There are large structural changes in the brain during adolescence. This occurs through two important processes:

1. Synaptogenesis
   This refers to the formation of new synapses and occurs both during prenatal development and after birth. In adolescence, the connections between neurons change as most of the neurons are in place. This allows for plasticity.
2. Pruning
   This refers to the elimination of the synapses and is experience-based fine-tuning of functional networks (i.e. ‘use it or lose it’). Synapses that are not used will be eliminated. This allows for a more functionally connected and specialized brain.

Overproduction (i.e. exuberance) refers to the thickening of synaptic connection and this mainly occurs around the time puberty begins. The disadvantage of pruning is that the brain becomes less plastic.

There are regional differences in grey matter as brain development occurs at different rates for different brain areas (e.g. prefrontal cortex develops later into life). There are also regional differences in myelination. Myelination is believed to be relatively experience-independent. White matter is mainly involved in structural connectivity.

Brain development is influenced by the social environment and by pubertal hormones as they are able to pass the blood-brain barrier. An enriched environment can lead to increased brain development. This may mean that people with a lower socio-economic status have a different brain development (e.g. slower; poorer). It may specifically influence the anterior cingulate cortex (i.e. more activity with a more enriched environment) and the amygdala, striatum and hippocampus (i.e. more activity with medium family income).

The relative size of the neocortex is associated with the size of the social group. There are several systems in the brain:

• Cognitive control (i.e. self-regulation)
  This includes the lateral parietal cortex (1), lateral prefrontal cortex (2) and the anterior cingulate cortex (3).
• Valuation and emotion
  This includes the amygdala (1), ventral striatum (2) and ventromedial prefrontal cortex (3).
• Social cognition
  This includes the posterior superior temporal sulcus (1), temporal parietal junction (2) and the medial prefrontal cortex (3).

The medial prefrontal cortex is associated with thinking about social contact and how one is perceived. The systems together make up the social brain (i.e. social information processing network), the network which is active with social contact. It is associated with shame (1), guilt (2), self-focus (3), mental state attribution (4), shifting of attention to others (5), perspective taking (6), face recognition (7) and biological motion (8).

The valuation and emotion network is also dubbed the socioaffective circuitry. It is critical for detection of salient information (1), assignment of hedonic, aversive or emotional value to that information (2), social cognition (3 and the use of that information to guide learning and behaviour (4). The socioaffective circuitry may be especially important in adolescence for several reasons:

• The prefrontal cortex continues to develop.
• The influx of hormones during puberty may sensitize functional properties of certain brain circuits.
• The connections between subcortical and cortical brain regions continue to strengthen.

The growing connections and the sensitization may reduce the capacity to exert cognitive or emotional regulation, especially in emotionally salient contexts. Sensitized socioaffective circuits which are not optimally regulated (i.e. due to an immature prefrontal cortex) could sharpen the detection of and response to salient cues during adolescence.

The affective networks develop sooner than the regulation networks meaning that there is more emotion than regulation in early adolescence. This may lead to risk-taking behaviour. This decreases with age (i.e. later adolescence). Changes in cognitive, social and affective processes in adolescence is linked to the changes in brain structure and function that can be observed during adolescence. There is thus a discrepancy between the matured emotional processing network and the control network.

The dual system model states that there is a motivational limbic (i.e. hot) system and the prefrontal control (i.e. cool) system. In adolescence, the motivational system cannot be fully controlled by the control system yet. The triadic model states that there is a difference between positive and negative affect and this is controlled by the prefrontal cortex. However, in adolescence, this balance is not fully there yet due to the prefrontal cortex not being fully developed yet.

In adolescence, there is a heightened reward sensitivity as demonstrated by an emotional go-no-go task. Adolescents show heightened activity in the ventral striatum and amygdala during this task.

Adolescents show increased attention and neural activation in response to peer acceptance. Social contexts are more salient to adolescents and this can lead to different decision-making abilities around peers (e.g. presence of peers increases risky decision making). Adolescents who feel rejected are more likely to engage in risky behaviour to fit in with the group.

The ventral striatum supports learning from positive social feedback from peers. The most reinforcing peers have a greater influence on social preferences. Feedback from peers may reinforce behaviour due to overlapping neural circuitry for evaluating social and non-social rewards.

Positive learning rates refer to learning rates as a result of positive reinforcement. Adolescents have lower positive learning rates than children and adults. When they receive positive social reinforcement, they show greater activity in the supplementary motor cortex and the putamen. The motor cortex activation is associated with faster responses to cues of the least reinforcing peer. This may reflect a heightened motivation for peer approval.

All positive social reinforcement equally motivated adolescents (i.e. lower positive learning rate). This may be explained in three ways:

• Adolescents have increased motivation toward that which is socially the least reinforcing (i.e. wanting to be liked by everyone).
• Adolescent behaviour may not be captured by simple reinforcement learning.
• Adolescents do not learn to discriminate between the cues that are associated with different amounts of positive social feedback.

They show elevated activity in the response planning circuitry when they receive positive feedback, regardless of the expected outcome. Adolescents may thus have an overall vigilance to peer approval. Peers could thus enhance risk behaviour.

The insula plays an important role in processing emotional salience and there is heightened activity in the insula to social cues in adolescence. The heightened activity in the insular cortex and regions within response planning circuitry suggest an affective-motivational sensitivity toward any peer approval.

There are adolescent-specific increases in the motivational salience of peers. This influences neural circuitry function and this, in turn, increases sensitivity to peer approval and learning in the adolescent.

Social sensitivity refers to the heightened attention, salience and emotion relegated to processing information concerning social evaluations and social standing in adolescence. This could intensify socioemotional processes (i.e. more attuned to instances of perceived social evaluation). There is more social evaluation and focus on social evaluation in adolescence as indicated by several things:

• Embarrassment peaks in adolescence.
• There is heightened activity in the medial prefrontal cortex (i.e. self-directed thought) during exclusion in the Cyberball paradigm.
• There is a decline in mood after ostracism in the Cyberball paradigm.

Social feedback can be measured using a photograph task (1), chatroom tasks (2) or by using the Cyberball paradigm (3).

The level of activation in the MPFC predicts how resistant adolescents are to peer influence. More activation reflects more value being placed on what other people think of them, meaning that more activation is indicative of less resistance. This relationship does not hold for adults.

The ventral striatum (i.e. reward system) shows increased activation for adolescents when peers are present and adolescents take more risks in the presence of peers. This may indicate that the presence of peers is seen as rewarding. Activity in the striatum during peer presence is associated with peer influence. This suggests that the more rewarding peer presence is, the more influence peers will have. The greater emotional response to disagreement (i.e. body image paradigm) predicts more conformity.

Adolescents engage socioaffective processes and reduce recruitment of regulatory circuitry while processing emotional qualities of social feedback. They often feel like they are under constant scrutiny (i.e. imaginary audience).

Prosocial behaviour refers to actions that are intended to benefit other people. Developmental models suggest that the shift to cooperative behaviour is the result of the development of several things:

• Increased empathetic concern (i.e. Hoffman)
• Advanced perspective taking.
• Cognitive control.

The pain matrix in the brain is activated when experiencing and observing others in pain. The social brain regions are activated when the harm is intentionally inflicted. Adolescents show more activation in the affective brain regions when observing others in pain whereas adults show more activity in the prefrontal regulatory brain regions. This means that adults are better at down-regulating their emotional responses.

Social perspective taking refers to the ability to infer others’ thoughts, intentions motives and attitudes. Role taking refers to the ability to assume another person’s perspective and understanding one’s intentions, thoughts, feelings and behaviours. Perspective taking develops through several stages:

1. Egocentric or undifferentiated perspective (3 to 6 years)
2. Social-informational role taking (6 to 8 years)
3. Self-reflective role taking (8 to 10 years)
4. Mutual role taking (10 to 12 years)
5. Societal role taking (12 to 15 years and older).

Intentions become more important with age as people demonstrate that they rather have nothing than an unfair offer in an ultimatum game. There is increased temporoparietal junction activity with age and this suggests more perspective taking. Temporoparietal junction activity mediates the relationship between age and rejection rate of an unfair ultimatum. The dorsolateral prefrontal cortex activity increases with age. This suggests increased regulation.

Adolescents do not seem to change their beliefs after positive feedback. The putamen is active when receiving positive social feedback regardless of the expected outcome. Peer approval may motivate adolescents towards action.