What is the history of neuropsychology?

The history of neuropsychology is characterized by fluctuations of periods in which the focus is on localization or on holism.  Localization refers to specific behavioral effects of several disorders in individual parts of the brain, and holism refers to the general behavioral effects of disorders in the brain as a whole. Gall’s phrenology is the best-known period of localization. After Gall, the emphasis was on holism. Later, because of the studies of Broca and Wernicke, the emphasis was on localization again. Broca and Wernicke discovered aphasia, a language disorder which is the consequence of brain damage. Around the First World War, holism started to gain the upper hand again, which was especially due to Goldstein’s search for one common and fundamental psychological disorder. This holistic period led to tests and tests batteries. The goal of these tests was to determine and measure the psychological consequences of brain damage. These tests were called ‘organic tests’.

Later, a struggle arose in the field of neuropsychology between the clinical, more qualitative approach and the methodological, statistical, quantitative approaches. The Dutch neuropsychology is currently dominated by Lurian and experimental influences. Also, insights, theories, and facts obtained through localization and lateralization research are also important. However, there is a lot of interest in ‘holistic issues’, such as ‘quality of life’. The current view is that brain dysfunctions have consequences that stem from both selective, localization-related disorders as well as more general consequences.

What are the possible misconceptions about neuropsychology?

One important misconception is that neuropsychology involves only the examination of functional cognitive disorders and intellectual deterioration. However, emotional disorders and personality changes also occur as a direct result of damage to for example the frontal lobes. It is also important to note that neuropsychologists also determine which of the patient’s functions are intact or relatively intact.

Another misconception is the idea that the explanation question (Chapter 1) requires an answer in terms of a medical diagnosis. This is not part of the job for a neuropsychologist. Instead, he draws conclusions on the basis of cognitive functional domains and their influence on the behavior.

A final misconception is the idea that the neuropsychologist should limit his or her examination entirely to the question of the initiator. This is not the case: sometimes new and more important questions can arise, which the neuropsychologist then should try to answer.

What are the types of questions?

Neuropsychological questions can be divided into three types:

The first type of question is the most general and basic: What is the cognitive profile of the patients? To answer this question, behavioral, cognitive, and emotional disorders should be identified.  An example of this type of question is: Can the memory complaints reported by the patient be attributed to underlying memory disorders and/or is there an indication of underperformance, aggravation or mood-related problems?

The second and third type of questions address the relationship between behavior and the brain. The second type refers to damage and/or abnormalities that have already been identified, while the third involves asking the question of whether there may be other brain abnormalities, and if so, which ones.

What are measurement instruments in neuropsychology?

The diagnostic methods that have been discussed in other chapters of the book are also used during neuropsychological examination: anamnesis and heteroanamnesis, the interview, observation, questionnaires, tests, and experiments. In this section, the instruments that are most frequently used and that are psychometrically the most favorable will be discussed. The current available neuropsychological tests can be classified into four groups: 1) general level tests and screening tests, 2) specific tests for cognitive functioning, divided into functional domains, 3) tests for emotional functioning, personality and attitudes, and 4) clinimetric methods.

Level tests and screening tests

The most common used intelligence tests are the WAIS (Wechsler Adult Intelligence Scale), the GIT (Groninger Intelligence test), the Raven’s Progressive Matrices, the KAIT NL (Dutch adaptation of the Kaufman Adolescent and Adult Intelligence Test), and the SON-R (Snijders-Oomen Non-verbal Intelligence Test). Intelligence tests should not be used as a screener for possible disorders in cognitive functioning.

Screening tests are tests used to screen for dementia. For example, the Mini-Mental State Examination (MMSE), the Cognitive Screening Test, the MoCA (Montreal Cognitive Assessment), and the Amsterdamse Dementie Screeningtest. It is advisable to have a low cut-off score when using these questionnaires. The goal should be to refer the client to an experienced neuropsychologist, who can then conduct a full neuropsychological examination.

During an examination of the cognitive functions, the following cognitive domains should be examined: attention, information processing speed, perception, memory, and learning, language, spatial functions, and executive functions (planning, behavioral regulation). The neuropsychologist will focus on the ‘higher’ brain functions, which means that he or she will ensure that there is no evidence of lower sensory dysfunctions, such as deafness, blindness, or dyslexia.

Attention

To assess selective attention, distractibility and the ability to inhibit responses, the Stroop test can be used. The Stroop test is based on the principle that reading is an automated process and that there is inference (distraction) between naming the color of the ink and the name of the color that is read aloud. An example of this is the word green, which is printed in red ink. The correct response would be ‘red’. Thus, the dominant response (‘green’) must be inhibited and selective attention must be focused on the naming of the color. This produces a delay, and the extent of the delay provides insight into the ability to selectively focus attention and to inhibit responses. Another test used to assess sustained attention is The Bourdon test. This test involves a sheet of paper that shows fifty lines with groups of dots, which contain either three, four, or five dots. The patient must cross out each group of four dots. Then, the following elements are scored: the average time that the patient spends on each line, the consistency of the time taken, and the number of errors. This test reflects how well the patient can concentrate for long periods of time (10 to 15 minutes). When a patient experiences neglect or hemineglect, the patient pays no attention to the stimuli from the contralesional side. This can be tested with tests such as the Behavioural Inattention Test, and with so-called crossing-out (cancellation) tasks.

Information processing speed

Among patients with brain damage, inertia is a common complaint. It is good to have information of the processing speed, because this may have an impact on the additional test profile of the patient. Information processing speed can be assessed in different ways. A distinction should be made between psychomotor speed, simple information processing, and complex information processing. However, a good reaction time instrument with corresponding norms is not available.

Perception and visuospatial functions

If there are doubts about the functioning of sensory organs such as the eyes and the ears, one can use The Cortical Vision Screenings Test (CORVIST). This is a short screening instrument. One can also use the Visual Object and Space Perception Battery (VOSP). When combining these tests, underlying disorders can be examined in more detail. For evaluating facial recognition abilities, one can use The Benton Facial Recognition Test. To assess visuospatial functions, one can use the Benton Line Orientation Test and maze tests. To assess auditory recognition, one can use The Seashore Test.

Memory and Learning

To assess procedural memory, one can only use experiments, because there are no normed tests. There are different tests for declarative memory, in which there is a distinction between ‘registering information’, ‘learning new information’, ‘retaining information’, and ‘recognizing information’ for both verbal and non-verbal materials. Some famous neuropsychological task for verbal memory are the 15-Woordentest (15-Word test) and the 8-Woordentest (8-Word test). Repeating the verbally or non-verbally offered sequences in reverse order shows the capacity of the working memory.

The semantic memory is often assessed using semantic fluency tests, in which the subject must recall as many examples of a category as possible (animals, fruits, words that begin with a certain letter).

Language

Tests that look at aphasia, problems in language, make a distinction between utterances (expression, production) and language comprehension (reception, comprehension) and between disorders at the word or sentence level. The test battery from the Stichting Afasie Nederland (Dutch Aphasia Foundation) is used to assess language that is both spoken and hear. The Akense Afasie (Aachen Aphasia Test) Test contains subtests for reading and writing. The Amsterdam-Nijmegen Test voor Alledaagse Taalvaardigheid (Amsterdam-Nijmegen Everyday Language Test) focuses on verbal communication skills in everyday life. The Semantische Associatie Test (Semantic Association Test) is a newcomer which focusses on the accessibility and availability of an adequate semantic network. The Token Test can also be used for screening for aphasia.

Executive functions

The term ‘executive functions’ refers to things such as coordination, controlling, and planning. Common tests to assess executive functions are the Wisconsin Card Sorting Test, the Tower of London test, the Trail Making Test and the Stroop test.

Praxis

Sometimes, practiced purposeful actions such as using a comb, putting on a coat, and waving goodbye are impaired in patients with brain damage. The most common tasks that are used for this purpose in clinical practice are the Luria tasks and the Goldberg tasks. However, there are no adequate norms for these tasks.

Emotional and personality problems

To assess emotional and personality problems, the neuropsychologist is often limited to observations, interviews and questionnaires. An example of a questionnaire is The Hospital Anxiety and Depression Scale (HADS). Tests that assess the tendency to aggravate and simulate (‘malingering’) are for example the Amsterdam Short-Term Memory test. The Test of Memory Malingering is also used.

Clinimetric methods

Clinimetrics focuses on instruments that measure the effects of illness and abnormalities. Initially, the focus was on rating scales for illness-specific and generic symptoms and general limitations in everyday life. Later, more complex concepts such as functional health and quality of life were introduced.

What are the common interpretation problems?

The most common problems in the interpretation of neuropsychological data are test conditions, premorbid functioning, multiconditionality, and the relationship between sensitivity and specificity.

Test conditions

When one carries out measurements using tests or other measurements, it is assumed that the person undergoing this test meets basic conditions. For example, we assume that the person understands and remembers the instruction, that he or she is able to respond to, etc. However, patients with brain damage sometimes do not meet the conditions. It is even the goal of diagnostics to find out whether the patient is ‘testable’ or not.

Premorbid functioning

Often, there is no data available from the time before the illness or accident. When psychologists then want to draw conclusions about acquired brain injury, they need to use reasoning and reconstructions. There are different types of reasoning. First, they can use the anamnesis and heteroanamnesis and ask the patient’s inner circle about his or her functioning. Second, they could assume that the patient functioned ‘average’. Third, they could estimate the premorbid intellectual level on the basis of the Dutch Reading Test for Adults and on the basis of the patient’s age and education.

Multiconditionality

Test scores on neuropsychological tests are not only influenced by brain damage, but also by other conditions and factors such as age, level of education, gender, genetic differences, etc. Therefore, psychologists must always ask themselves which factors aside brain damage may have affected the results. So, the interpretation of both the recognition and explanation of neuropsychological problems consists of three steps. First, an unexpected outcome leads to a hypothesis. Second, there is a search for confirmation of this in other data. Third, the psychologist will go through all the available data in search of a contradiction.

Sensitivity and specificity

These terms refer to the distinctiveness of a test score with regards to an external criterion. Sensitivity reflects how often low test score (below a cut-off score) is obtained by people with the relevant diagnosis, and specificity refers to how often a good test score (above a cut-off score) is obtained by people without that diagnosis. For example, 100% or almost 100% of patients with a diagnostic amnestic (memory loss) syndrome should obtain a low score on a memory test, and around 100% of the healthy patients should obtain a high score. Raising the cut-off score would increase sensitivity, but decrease the specificity. The patient’s individual question will determine whether there should be more value attached to sensitivity or specificity.