Clinical Neuropsychology_Kessels_1st_Chapter_1-3

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How has clinical neuropsychology evolved? - Chapter 1

Where does clinical neuropsychology come from?

A clinical neuropsychologist (in health care) focuses on the diagnosis and / or treatment of problems that are related to brain damage. Clinical neuropsychology used to be - and in some countries still is - the field of psychiatrists and neurologists. Over time, clinical neuropsychology has expanded to an independent discipline. More than 2,400 years ago, Hippocrates was convinced that behavior and feeling are the result of brain functioning. Nobody believed him and for centuries the Greeks and Romans believed that the body knew a balance between the elements of water, fire, blood and mucus. A disruption of this balance would lead to illness or abnormal behavior. Only from the 14th century (the Renaissance) did the people start to think critically. Two notable scientists / philosophers in history:

René Descartes (1596-1650)

Descartes. The soul is an independently functioning intangible unit.

Franz Joseph Gall (1758-1828)

Gall introduced the notion that there are many mental organs in our brains. His views were tested using the clinico-anatomical method: the cognitive loss of function as a result of brain damage (in the language area, for example) was studied in patients, and subsequently the brains of patients were analyzed after their death, after which the location of the lesion was related to the type of functional impairment. Gall formed the very first foundation of clinical neuropsychology as we know it today.

What is cell theory?

The ancient Greeks distinguished between three different forms of soul. According to the ancient Greeks, man was the only one who had all three forms of the soul: a soul to survive, a soul to engage in activities, and a higher-order soul that knows the difference between good and bad. This higher-order soul - the mind - is said to be located in the empty cavities of the brain (the brain ventricles) that were called cells at the time. The first cell (sensus communis) collects all sensory information and forms an image; in the second cell the image (the psychological representation) would be interpreted: what does the image mean? The image is stored in the third cell (memoria). Cell theory has been important for the contemporary cognitive psychology. It is a general system of information processing (our mind can process all types of information) and is the same for everyone. The physiognomy, on the other hand, is about the individual differences in personality or character. Physiognomy means that someone's appearance says something about his or her personality and is attributed to Aristotle.

What did Descartes think?

Descartes renounced all the new insights that developed within the Renaissance and went alone or on what was indisputably true ("I think, so I am."). He stated that people are composed of two substances: the body (res extensa) and the mind (res cogitans), whereby the res cogitans can be seen as a kind of driver. Although the mind would be immaterial, it did place it inside a cavity in the middle of the brain: the epiphysis or the pineal gland.

What did Gall think?

Gall drew up plans for a new psychology, which he called phrenology. He assumed that all psychological functions (including knowledge and affect) are innate. He stated that the mind is not a general information processing system, but that there are specific, separate organs for music, arithmetic and even motherly love. Someone who is better at music has a larger "music organ". The organization is the same for all people (and animals): only the size can vary. His localization was based, among other things, on research into brain damage: for example, he correctly located the language in the front part right behind the eyes. His localization ideas broke with the idea of ​​one soul and Descartes' undivided mind and formed the very first basis of our neuroscience. In addition, Gall argued that the mind is not in the center of the brain, but on the outside: the cortex. Until then the cortex was only seen as a dried-up crust with no specific function. According to Gall, the brain had independent functions, which at the time was a revolutionary idea.

What is the clinic-anatomical method?

The clinico-anatomical method was used to test Gall's localization ideas by mapping the specific loss of function and later relating them to the site of the lesion. This method was widely used in the 19th century. Paul Broca showed that patient Tan's lesion (sir could only say "tan") was not in the language area as designated by Gall, but more on the side in the left frontal lobe (Broca's area). He noticed that the lesions were almost always in the left hemisphere and he was the first to prove that we use our left hemisphere to speak. This was also the first time that an inequality of the brain halves was demonstrated. His work was universally accepted virtually without challenge. Subsequently the idea arose that the language function could be divided into sub-functions (until now, only speech production had been considered). Carl Wernicke argued that there was a separate center in the temporal lobe for recognizing (only spoken) words. From this dichotomy the distinction arose between Broca's aphasia and Wernicke's aphasia.

What is associationism?

Locke, a huge proponent of empiricism, did not believe in the innate functions as Gall, Broca, and Wernicke claimed. Locke stated that everything is learned: a vision that is also called associationism. John Hughlings-Jackson pointed out to Broca that the location of the lesion can lead to a specific failure, but that it should not be confused with the location of an entire function.

What is holism?

Around 1900 there was much opposition to the localization movement: according to Constantin von Monakow areas of the brain generally worked together. The Gestalt movement (the whole is greater than the parts) increased strongly and Henry Head called localizationists 'diagram makers', putting him in a bad light. Many counterparts of localizationism warned of a great simplification, but they did not have a good alternative: even holists accepted a certain degree of specialization. The Russian Aleksandr Luria offered them the solution in the mid-20th century by coming up with a good balance between localizationism and holism.

What did Luria think?

Luria clinically observed a lot of soldiers who had suffered brain damage during World War II. He was one of the first who focused on the rehabilitation of patients with cognitive disorders and was guided by neuropsychological theory and assessment. He described the brain as a single complex functional system in which multiple subsystems make their own contribution to joint activity. He stated that it is never possible to draw direct conclusions about the responsible subsystems: a holistic view. On the other hand, Luria was a localizationist because he was certain that an accurate analysis can show a specific disruptive factor. With his global model, Luria made a distinction between the following areas:

There are three units that are continually interacting with each other, these are related to the subcortical, posterior and anterior brain areas.

Within each of these units, a distinction can be made between three hierarchically organized levels of processing: the primary, secondary, and tertiary zones in the brain. The primary areas are the well-known centers for modality-specific sensory information. The secondary zones process the information and give it meaning. In the remaining tertiary zones multimodal integration, the formation of intentions, and the evaluation of one's own behavior takes place.

Although Luria emphasized that for every complex behavior intensive collaboration of both hemispheres is necessary, he denied any involvement of the non-dominant hemisphere in language and speech processes. On the other hand, he regarded the phenomenon of hemispatial neglect as one of the few symptoms exclusive to the right hemisphere.

What is a test battery?

A test battery is often used as a screening tool: cognitive functioning is systematically described in a relatively short time. 

Which two developments contributed to the independence of neuropsychology?

Around 1960 there were two major developments in the United States. This resulted in the emergence of neuropsychology as a separate scientific discipline:

After making acquaintance with Wernicke's work, Norman Geschwind encouraged many to look for specific areas and connections to better map the functioning of the brain. He wrote an influential article about disconnections, the importance of analyzing functions and double dissociations.

Roger Sperry investigated the effects of the split-brain surgery: in patients with severe epilepsy, the fiber tract that connects the two hemispheres (corpus callosum) was cut. This kind of surgery seemed to be a surprising success: epilepsy decreased and functions such as perception, language and memory seemed intact. 

In sum: neuropsychology became an independent discipline (initially in science, but later also in health care) due to the rapid development of research into the different hemispheres and language disorders. Arthur Benton (1909-2006) was one of the fathers of clinical neuropsychology and he wrote many influential articles about patients with aphasia and other types of cognitive impairment.

What are important concepts in cognitive neuropsychology?

(Modules) An example of a module is the language module. We do not have awareness of these processes, and we do not have control over them. We can hardly even influence it. According to Jerry Fodor, a module is domain-specific, innate, encapsulated and has a fixed neural architecture. David Marr also plays a major role in the theory development of cognitive neuropsychology. Marr engaged in the rules (algorithms) that are needed to convert certain information (input) to other information (output). For example, our brain translates sounds into meaning. Marr's approach is based on serial processing: information is converted to the subsequent level of representation. Not much later it became clear that information is not strictly processed serially, but that there is also parallel processing. Influenced by Fodor and Marr, researchers started looking for models of different functions and tried to explain disorders with these models. In particular, much research was done into acquired dyslexia (John Marshall and Cox Coltheart) and agnosia (Elizabeth Warrington): an inability to recognize objects. 

What are neural networks?

Computer programs - called connectionist models - can mimic certain cognitive functions because they work in the same way as the brain: there is a large network of nodes (cells) that are connected to each other (by dendrites). Certain connections are strengthened by learning processes, which can in turn result in a particular response strengthens a response. This is congruent with the association learning of the functioning of memory. There are at least three characteristics of such models that correspond to the functioning of the brain:

A model is 'economical' because a neural network also learns through trial and error.

'Graceful degradation': if certain nodes are damaged, the entire function will not be lost but part of the information will be lost.

'Content addressability': a small amount of the information (a few letters) can activate the entire memory trace (the whole word).

Nevertheless, it is clear that the anatomical and physiological properties of the brain differ in several important respects from those of neural networks. The networks offer little insight into how the process actually works. The model is mainly descriptive rather than explanatory. 

What is neuroimaging?

Computed tomography (CT) is an imaging technique that can detect brain injury. "Magnetic resonance imaging" (MRI) significantly increased the possibilities of neuroimaging. With an "electro-encephalography" (EEG) and then mainly with "event-related potentials" (ERPs), more insight was gained into the functional (rather than anatomical) properties of the brain. A consequence of the development of imaging techniques was that more attention was paid to the neural correlates and physiological processes of all kinds of cognitive processes. As a result, less attention has been given to theory development.

How does neuropsychology work in practice? - Chapter 2

When did the clinical field of neuropsychology establish?

This chapter focuses on the work of the neuropsychologist. It is a relatively young field of work: in the United States this field established itself at the beginning of the twentieth century; in the Netherlands only in the second half of the same century.

What does the Neuropsychological Examination consist of?

What does the diagnostic cycle consist of?

The diagnostic cycle consists of four stages: the complaints analysis, problem analysis, diagnosis and indication for treatment. After each step, hypotheses are formulated. These hypotheses are tested using data from the patient interview, observations, and neuropsychological tests and questionnaires. During the cycle, hypotheses can be adjusted or rejected. Sometimes the cycle is completed several times (in part), but sometimes it is also interrupted prematurely if further investigation does not prove useful.

What do referral and research questions mean?

It is of great importance that the referrer's question (often a medical specialist or fellow psychologist) is specific and clear. If it is not clear, it must be clarified. During the examination, the psychologist will add additional research questions if the examination renders this necessary.

What is a case history?

During an anamnesis the patient is always interviewed about the complaints, education, work, medication use and medical history. The patient will often spontaneously list his / her complaints, after which the psychologist will discuss the development of the complaints. A standard list of questions is often used, but is not enough. Asking further is very important (with visual hallucinations you quickly think of a psychotic disorder, but not a burnout). The psychologist also gets a general first impression of the cognitive abilities, the insight into the illness and the behavior of the patient. The patient can also be reassured or motivated if necessary.

What does an interview with the informant consist of?

A conversation with only the patient is not enough. During the interview with the informant, the partner, the parent, the children or even the neighbours, friends or the doctor are asked for information. As a rule, permission for this is requested from the patient. A clear case in which an interview with an informant is essential is in the case of a suspected frontotemporal dementia: there is no insight into illness and there is a change in personality that is often not spontaneously mentioned by the patient himself.

What is an observation?

Observations can be collected at any time during the examination. It is important that the observations are independent of interpretations (so write down: "patient is crying" and not "patient is sad"). Observations can provide information about social interaction, cognitive capacities and motivations

What are tests and questionnaires?

There are different types of tests and questionnaires: screening tests, standardized test batteries, tests that focus on one cognitive function, behavioral neurological tests, self-assessment questionnaires, informant questionnaires, and observation scales. A fixed battery of tests is often used for scientific research; in a neuropsychological examination a flexible test battery is used more often, which takes more work because it specifically focuses on complaints and questions. The reliability and validity of tests and questionnaires, the available standard data, the distinctive character, and the presence of parallel versions must always be taken into account. The paper-and-pen tasks are still used. Advantages of computerized tests are the decrease in standardization, the accurate recording of responses, and time saving. A computerized test is especially recommended when (sustained) attention and the reaction time are being measured.

What does interpretation mean?

The interpretation involves the integration of the anamnesis, the interview with the informant, the observations and the test results. Are the results reliable and valid? Are there any factors that could have influenced the test scores, such as fatigue and nervousness? How are the standard data determined, has age and education been corrected? The differential diagnosis must also be carefully examined: are there possibly other explanations for the symptoms?

What does reporting contain?

The written report is initially drawn up for the referrer. The content and length will vary depending on personal style and on the purpose of the report. The content of a psychological report must be discussed with the patient before the findings are reported to the referrer or discussed within a multidisciplinary team. However, this is sometimes not desirable, for example when the neuropsychological examination is part of a multidisciplinary process and the diagnosis is not yet known. In such a case, the psychologist can discuss the results, but it is better not to make statements about possible causes or diagnoses: this is done in the final conclusion of the study. The patient will often ask for a copy of the report: this may only be refused in exceptional cases. The code of the Dutch professional organization for psychologists (NIP) also describes the other rights of the patient, such as the right to perusal, correction, or blocking. 

What are validity and reliability?

What is reliability?

The reliability of a test specifies the accuracy of the test. The test-retest is the extent to which a test yields the same results when it is taken at different times by the same person. This is indicated by a correlation coefficient. The inter-rater reliability measures the degree of agreement between the results of several researchers, which is presented as Cohen's kappa.

What is validity?

The validity of a tests consists of different subtypes:

Face validity: does the test seem to measure what it is supposed to measure?

Content validity: is the test is representative of the topic that is to be measured?

Example: an intelligence test that consists of several subtests has a higher content validity than an intelligence test that only consists of number series.

Construct validity: to what extent does the result of the test actually reflect the cognitive function that is measured? Example: to what extent does the score on the number series actually say something about the working memory?

Criterion validity: to what extent does the test predict the actual behavior of a patient with regard to an external criterion (predictive validity) and what is the similarity between this test and another instrument with the same measurement pretention (concurrent validity)?

Ecological validity: how does the score on a test predict the functioning of the patient in his / her own environment? This is very similar to predictive validity. There is much criticism of the predictive value of traditional tests since a structured test situation cannot be compared to a work situation.

What is a confounding factor?

A confounding factor is an element that influences performance on a test but that does not fall within the measurement objective of that test. For example, sensory limitations, cultural background, limited education, fatigue, pain, emotional absence and motivational problems.

What does underperforming mean?

Underperformance - or suboptimal performance - is a disturbance factor that makes the patient perform worse than what he / she is capable of if he / she would be able to achieve if they were to make a normal effort. This can be caused by extreme tiredness or nervousness, pain, worries or financial reasons. Non-existent symptoms can also be pretended (simulated) or existing symptoms may be exaggerated. Underperformance can be assessed by looking at inconsistencies within the test profile or by noticing a clear discrepancy between the test scores and actual behavior. In some patient groups, the prevalence of underperforming is quite high (this is often the case with a whiplash where the patient benefits from underperforming in connection with insurance and sickness law). Symptom validity tests have been developed to detect underperformance. The underlying idea of ​​symptom validity testing is that performance below the level of patients with brain injury is suspicious, since the tests appear difficult but very easy and measure a function that is still intact in almost all patients with brain damage. A reason for intentionally underperforming is for example in forensic neuropsychological examinations, with the goal of getting a sentence reduction.

What is the neuropsychological treatment?

Initially neuropsychological treatment focused on cognitive impairment, but in recent decades more attention has been given to the emotional and behavioral consequences of brain injury (such as anxiety, mourning, relationship problems, sexual problems, aggression and inhibition). The neuropsychologist not only monitors the treatment plan and the learning methods, but also the learning pace. He also advises professionals in other disciplines within the team.

What does the professional field of the neuropsychologist consist of?

What does a neuropsychologist do in a hospital?

In an academic hospital, neuropsychologists are often attached to a university and carry out more scientific research compared to neuropsychologists working in a general hospital. In the hospital the neuropsychologist collaborates closely with a number of specialties, including neurology, geriatrics, rehabilitation, neurosurgery, and internal medicine. Sometimes there is a psychiatric department with psychiatrists. The main task is to perform outpatient diagnostics. Treatment administered in a hospital is usually short term and complaint oriented. Here the emphasis is mainly on psychoeducation.

What does a neuropsychologist do in a rehabilitation center?

Within a rehabilitation center you will be part of one or more multidisciplinary teams. The emphasis is usually more on treatment than on diagnostics. Nevertheless, the diagnostics are an essential part of the work carried out in a rehabilitation center. It provides insight into neuropsychological disorders that can form an obstacle to treatment, and it also ascertains remaining abilities that can be used in treatment, such as an intact learning ability or an ability to benefit from structure. A neuropsychologist often has an important management function in the team and he / she often works closely with a cognitive trainer. The neuropsychologist focuses primarily on neurological disorders such as stroke, multiple sclerosis, and traumatic brain injury.

What does a neuropsychologist do in mental health care?

The neuropsychologist works closely with psychiatrists, psychologists, activity counselors and psychiatric nurses. The work carried out with admitted patients can be divided into acute care and chronic care. In the case of ambulatory patients, patients only come to the institution for treatment. Psychoeducation to the patient and family and friends is very important. Here the neuropsychologist will often be involved in meditative treatment, whereby he / she tries to influence the behavior of the patient positively through the environment. Diseases are mainly mood disorders, psychotic disorders, ADHD, addiction and autism spectrum disorders.

What does a neuropsychologist do in a care or nursing home or assisted living forms?

Most patients in a care home or nursing home are of an older age. The departments are often subdivided into somatic departments (physical care) and psychogeriatric departments (dementia). The neuropsychologist tests cognitive functioning, thinks about the possible causes, the prognosis and the treatment. Usually placement advice will be requested. Treatment methods can vary from cognitive rehabilitation (individually or in groups) to system therapy and drug therapy. He / she also advises on suitable living facilities and guidance of the environment.

What does a neuropsychologist do in a forensic institution?

Neuropsychologists are of importance in a forensic institution because of the is increasing evidence for the neurobiological basis of criminal behavior. The activities are always within a legal context (such as TBS, detention or imprisonment). The cognitive functions are mapped out within the legal framework. The neuropsychologist can also be asked about possible cognitive obstacles for a certain treatment. The reporting is subject to extreme requirements because of the enormous consequences that the statements of the neuropsychologist can have with regard to the deprivation of liberty.

What is the scientific approach to neuropsychology? - Chapter 3

What is this chapter about?

This chapter describes the types of questions and the importance of a dissociation and double dissociation. The recovery, course and treatment are also discussed. Often it is difficult to assess whether recovery is the result of treatment or spontaneous recovery processes. Another problem in determining this is the test-retest effect: Someone can show a better performance in the second test because he / she is already familiar with the test.

What is the difference between clinical neuropsychological examination and fundamental research?

A distinction is made between clinical neuropsychological research and fundamental research. In clinical neuropsychological examinations the focus is on further characterization of the clinical picture, examining the usability of the test instruments and test procedures and analyzing the course of a disease. Fundamental research focuses on increasing the understanding of the disorder and related brain structures.

What are clinically oriented neuropsychological issues?

The questions in clinical neuropsychological range from differential diagnostic questions to evaluating treatments and providing answers to advice questions. Diagnostic research has to be done according to the diagnostic (empirical) cycle. A major disadvantage of research on clinical questions is that the value of the conclusion is very dependent on the quality of the test, the available standard data and other psychometric properties of both tests and questionnaires. An even bigger problem is the matter of balancing between what is practically feasible on the one hand with the optimum test combinations on the other. It is impossible to offer all the tests that would measure part of the memory; moreover, the memory remains so complex that this cannot be included in all tests. A third limitation is the missing values that are the result of a test battery that is not fully completed by the patient (due to, for example, fatigue or aphasia).

What are fundamental issues?

The causes of disorders and underlying cognitive processes are investigated through experimental paradigms. It is not necessary to use standardised procedures, because the comparison is made within the experiment, as the different conditions are compared.

What does a research design look like?

What is subtraction?

Frans Donders introduced the reaction time paradigm by applying a subtraction method: in this procedure the score (for example reaction time) is subtracted from the score or a more complex task in a simpler condition. This subtraction method is often used for imaging research. In this case, not the reaction time, but the activation level represents a score. A comment on this procedure is the unreliability of the difference score: one condition has a certain unreliability just like the other condition and these are added together. Factorial designs (analysis of variance) can be used to solve this problem.

What are single and double dissociations?

In neuropsychology, a dissociation implies that there is a specific dropout but general cognitive functioning is intact. With a single dissociation there is a selective dropout for task A (complex) but not for task B (simpler), while in practice it has been shown that someone who fails in task B also fails in task A. This can be explained by the fact that task A is more complex than task B: sometimes capacities are saved for simple tasks. With a double dissociation, two independent tasks are clearly distinguished that were initially thought to be strongly interdependent. For example, one patient is not able to carry out task A but is able to carry out task B while another patient is not able to carry task B, but is able to carry out task A. An example of a double dissociation is the perception of objects and the perception of spatial relationships between objects. Only a double dissociation is not sufficient evidence.

How is a single-case study useful?

The patient Tan (Leborgne) and HM are well-known examples of single-case studies. Carmazza (1986) states that a single-case study is the only correct way to investigate cognitive impairment, due to the fact that no lesion (in form and impact) is the same for all individuals within a group study. In addition, it is often assumed that premorbid functioning is 'normal' in the heterogeneous group, whose focus is then on adaptability and functioning after a lesion. However, group studies are not useless: they offer a general framework and the possibility of generalization, and ultimately the single-case studies must also fall within this framework.

What does the design of a single-case study look like?

There are various designs for conducting a single-case study. First, the test score of the patient can be compared with the score of a normative group. Secondly, intra-individual research can be conducted: all kinds of specific tasks are performed and the conditions are compared with each other. In this case the patient's scores will have to be compared with the scores of a control group in which participants are matched to important characteristics.

What are course studies?

What is the difference between a longitudinal and a cross-sectional study?

There are two main course studies that both try to make statements about the course of a disease. A longitudinal study means that one or more patients are monitored and tested for a number of years, after which their data is analyzed. An important confound - disturbance factor - here is the test-retest effect which endangers the validity of the test. The solution to this problem is to add a control group that is also tested twice at the same interval. Cross-sectional research means that different groups of patients with the same syndrome are tested at different times. In this case, the 'average course' can only be discussed. Both designs have their advantages and limitations. That is why Salthouse advocates a combined design.

What are treatment studies?

Treatment studies look at the specific effect of treatment through pre-measurements and post-measurements. Here it is important that generalization takes place: the improvement must not only be noticeable on objective neuropsychological tasks, but also in daily life. The difference between the follow-up measurement and the pre-measurement does not necessarily have to be caused by treatment but can be the result of a non-specific effect such as improved motivation or reduced feelings of depression. If the improvement is noticeable in a wide range of cognitive functions, the improvement appears to be caused by a non-specific effect. A solution for this is the multiple baseline design in which multiple pre-measurements are made to find out whether there is already a spontaneous recovery.

What does a control task and a cross-over design entail?

To assess if a specific effect occurs after treatment, a control task can be used: if a patient is treated for function A, then there should be no improvement for function B after treatment. The placebo effect should also be considered, or the Hawthorne effect, where the extra attention for the patient can lead to improved cognitive functioning. The cross-over design is a variant of the control test: here a training is given for function A, after which the performance on function A and function B is measured. Subsequently, a training is given for function B and again the performance on function A and function B is measured. The training should only lead to an improvement in the trained function.

What does item-specific training entail?

There is a specific effect if only the specific items that are trained actually improve while the other items do not improve. With specific items you can think of naming certain pictures.

What is a randomization test used for?

A randomization test analyzes the probability of a certain pattern of scores when the test samples have been taken at random moments in time. For one patient, by chance, a different starting point is chosen than for the other patient. Subsequently, the course of the scores and the chance of a specific pattern are examined. It is also possible to look at two treatments within one person in this way.

What is the test-retest problem?

One of the problems with treatment studies is the so-called learning effect. The patient may have learned item-specific. This can be solved by working with parallel versions. A test-retest effect is not so much about item-specific learning, but about task-specific learning: the patient is familiar with the instructions, the situation and knows what is to come. This must be taken into account when drawing up the design: a control group must also be offered the repeated measurements but not the treatment.

What does generalization mean?

Within neuropsychology it is important that a certain result can be generalized. This means that a learned skill in a treatment is also useful in daily practice. For this reason, it can be useful to practice tasks that (almost) exactly match reality, such as shopping. If this is not possible, it is nevertheless important to pay attention to transfer. This means that similar exercises are done, in which the patient learns how to transfer the skill to daily life.

Which quality criteria are treatments subject to?

The SCED scale contains ten quality criteria that single-case studies must meet. This includes the adequate description of clinical data, a suitable design for establishing causal relationships and the quality of the baseline measurement. A relatively new criterion has been included under the term 'randomized controlled trial' (RCT). In an RCT, the patients are randomly placed in one of the conditions (experimental or control condition).