Lecture 1: What is neuropsychology: chapter 3/4 Flashcards
What is neuropsychology?
Study of the relationship between (physical) brain functions and behavior, emotions and cognitions
What are the 2 types of neuropsychological research?
- Fundamental neuropsychological research –> understanding of underlying cognitive disorders/processes and related brain structures
- Clinically oriented neuropsychological research –> Focused on improving assessment and treatment of brain disorders
What are the 2 main working domains of a neuropsychologist? What are 4 other working domains?
- Hospital
- GGZ
- Rehabilitation centres
- Forensic institutions
- Residential/nursing homes
- Specialized institutions (e.g. epilepsy)
What are neuromyths and how do they originate?
Misconceptions generated by misunderstanding, misreading or misquoting of facts
Neuromyths originate from overgeneralizations of empirical research, propagated by all kinds of popular media/films
What does it mean that neuropsychologists are scientist-practitioners?
They can diagnose and treat patients with brain disorders using their knowledge of empirically tested methods
What is a single-case study? Why is it used?
Research conducted in an individual patient
Used, because studies that compare groups aren’t always possible or relevant. Brain damage can vary greatly, so it is hard to compare
What is the test-retest effect?
The patient scores better at next test, not because of recovery but because of familiarity with the test
What is a difficult thing concerning developing a test battery for neuropsychological testing?
You have to balance what is practically feasible and the optimum test combinations.
Often 1 test represents ‘memory’ whilst the entire memory can’t be tested with just 1 test
What does it mean when you say clinical oriented research is missing values? Why is that a problem?
It can be possible that a test battery won’t be completed by a patient (e.g. fatigue, inability to perform the task etc.).
Missing variables causes problems with the analysis and interpretation of data (e.g. a mean group performance might be lower if the patients who dropped out had actually performed the task)
What is the Posner spatial orientation task?
Participant has to react as quickly as possible to a stimulus. A cue is given preceding the stimulus (either centre or periphery of visual field). The interval between cue and target stimulus varies and sometimes the target doesn’t correspond with the cue.
It demonstrates that the spatial orientation process consists of different stages. Different patient groups show impairments in specific stages of this process
What are 2 important methods in neuropsychological research?
- Subtraction method
- Single or double dissociation
What is the main idea behind the subtraction method? Who was the founding father?
It uses mental chronometry, consisting of the reaction time paradigm and pure insertions
Founding father = Donders
What is the reaction time paradigm in the subtraction method?
The use of reaction times to evaluate cognitive processes
What are pure insertions in the subtraction method?
A single cognitive process can be inserted into a task without affecting the duration of other processes
What are the 3 conditions in the reaction time paradigm of Donders? How does subtraction work between these conditions?
- Simple detection task
- Go/no-go reaction time task
- Discrimination reaction time task
3-1 : estimate of time required for discrimination of stimuli
3-1-2 : estimate of time required to make a response
How is the subtraction method applied in neuroimaging research?
Activation of simple condition is subtracted from the image of the complex condition. The activation that is specific to the complex condition remains
What are some problems with the subtraction method (3)? How can you solve each?
- Difference score is not very reliable because both conditions have already unreliability and then you combine the unreliability
–> Use factorial design - Fallacies of pure insertion: longer reaction times may be because of other mental processes involved in tasks
–> Include multiple tasks/contrasts - Limited ecological validity: gap between test and everyday behavior
–> Add questionnaires, observations
–> Use VR to standardize environment
What is the method of dissociation?
Identify the neural substrate of a specific brain function or the location of function using case studies, neuroimaging and/or neuropsychological testing
It relates to the selective loss of a function
What is dissociation in neuropsychology?
Refers to a selective loss of function
What is a single dissociation?
The patient can’t do task B (writing), but can do task A (reading)
It assumes a serial organization of function in the brain (reading –> writing)
Who was the founding father of the double dissociation method?
Teuber: it’s a method of demonstrating the existence of independent functions
What is double dissociation? Give an example
Demonstration of 2 independent cognitive processes that were originally thought to be a connected process.
Ability to recognize a person’s identity can be impaired, but emotional expression can be recognized and vice versa
How can you see the difference between single and double dissociation in a graph?
Single : one horizontal line, one line at an angle
Double: cross pattern
Why did the value of a double dissociation become less important? How can you account for that?
It became apparent that neural network models without specific/independent modules could show patterns of double dissociation. So a pattern of double dissociation doesn’t necessarily indicate independent modules
Account for it with statistical tests to see if patient’s performance indeed deviates from normal range
What are the 2 types of imaging in neuroimaging techniques?
- Structural imaging: visualization and analysis of anatomical properties of the brain
- Functional imaging: identification of brain activity and brain function
What are 5 methods for structural neuroimaging?
- CT
- MRI
- DTI
- VBM
- MRS
What are 5 methods for functional neuroimaging?
- fMRI
- PET
- EEG
- ERP
- MEG
What is the difference between spatial and temporal resolution? Which technique has the lowest temporal resolution and the highest spatial resolution?
Spatial: sharpness of the image
Temporal: speed of recording
EEG: high spatial, low temporal
What are the 3 axes a CT scan can scan?
- Sagittal: front to back vertical
- Transverse: horizontal
- Coronal: ear to ear vertical
What important finding did Golgi demonstrate?
Existance of individual neurons with the microscope
What important finding did Cajal demonstrate?
Showed that brain cells form independent units that communicate with each other
What is pneumoencephalography? What replaced this technology?
Invasive technique in which cerebral fluid is removed and replaced by air in the brain ventricles. The brain then is more visible on X-ray images.
This was very painful, so it was replaced by other techniques (echoencephalography: ultrasound pulses delivered to skull and reflected pulses are recorded)
What are the 4 stages of the diagnostic cycle? What happens in each stage?
- Definition of the problem: referral question study and interview patient and family and observe
- Observation: use tests/questionnaires
- Interpretation: use information from previous stages to interpret
- Reporting: report written and verbally and choosing most appropriate treatment
When is a hypothesis made in the diagnostic cycle?
It’s formulated for each stage
What is the difference between reliability and validity?
Reliability = stability of the results
Validity = if the test measures what it’s supposed to measure
What are the 2 types of reliability?
- Test-retest: similar scores if test is done again
- Interrater: similar scores if someone else administers the test
What is the difference between construct validity, criterion validity and ecological validity?
Construct: if test measures the construct that it’s supposed to measure
Criterion: if test scores correlate in an expected manner with the test scores measuring related constructs
Ecological: if the test conclusions are generalizable to the population
What is a confounding factor? Give an example of an important confounding factor in neuropsychological testing
An element that affects performance on a test but that doesn’t fall within the measurement objective of a test
Underperformance is an important confound
What is underperformance? What can account for that?
A patient’s capacity is underestimated due to them not giving their best effort
Include tests that test underperformance, such as a test that patients with brain dysfunction do well on
What do forensic neuropsychologist really have to be alert on?
Intentional underperformance, because some people might get lower legal consequences
What are 5 tasks of a psychologist in a hospital?
- Diagnosis
- Short-term complaint-oriented treatment
- Establish effectiveness of intervention (e.g. removal tumor)
- Collaborate with other disciplines
- Teaching/research in university hospitals
What are 4 tasks of a neuropsychologist in a rehabilitation centre?
- Assessment of level of functioning/strengths
- Assessment of whether client can live independently
- Treatment
- Collaborating with other specialities
What are 4 tasks of a neuropsychologist in mental health care?
- Contribute to treatment plan
- Treatment (psychoeducation, coaching family members)
- Assessment of side effects of medication on cognitive function
- Collaborate with other specialities
What are 5 tasks of neuropsychologists in nursing homes?
- Assessment
- Diagnosis
- Treatment planning
- Indication placement (live independently or not)
- Treatment
What are 2 tasks of forensic neuropsychologists?
- Exploratory diagnostics: is the criminal behavior result of brain dysfunctioning
- Treatment planning: if brain dysfunction will impair treatment
What are 4 limitations of neuropsychological testing?
- Hard to interpret if low reliability and low validity
- Test scores may not be able to distinguish between possible causes
- Tests may be not complex enough to reflect the full cognitive function
- Individuals with brain dysfunction may not have the capacity to do certain tasks –> Missing values
What are the 2 most popular structural imaging techniques?
CT and MRI
What are 3 aspects of CT (computed tomography) scanning?
- High resolution
- Produces slices of the brain in different angles
- Able to identify abnormalities
What are 3 aspects of MRI scanning?
- High resolution
- Clearer images of soft tissue compared to CT (distinguish between grey/white matter)
- Able to identify abnormalities in the brain
Why do people with strokes go into a CT scan and not MRI?
MRI takes longer, is more expensive. CT is done in 5 minutes and provides enough information to see what kind of brain injury there is
Also MRI isn’t suitable for everyone, since people with hearing issues or internal metal devices (pacemakers) can’t use it
What is volumetry?
Structural neuroimaging method using voxels and greyscales to calculate the volume for specific brain tissues
What is diffusion tensor imaging (DTI)?
Visualizes white matter pathways in MRI machine. This is possible because watermolecules behave differently in white vs gray matter. This is used to calculate fractional anisotropy (FA)
What is voxel-based morphology (VBM)?
MRI application that can measure the density of gray and white matter and the thickness of this matter
What is magnetic resonance spectroscopy (MRS)?
Application of MRI: non-invasive technique that can give information on concentrations of molecules. It makes use of hydrogen and phosphorus whereby energy release is detected and displayed
What are 2 nuclear medical imaging techniques for functional processes in the brain?
PET: positron emission tomography
SPECT: single-photon emission computed tomography
What is the difference between imaging and image processing?
Imaging: acquisition of data
Image processing: the processing of the acquired data
How does CT work?
With a little bit of Xray. Different types of tissue block the rays to a greater or lesser extent, which results in a 2D image of the body. A computer combines the images, making it possible to see all parts of the head in detail
What are the 2 most popular functional imaging methods?
EEG and fMRI
How does MRI work?
With a very strong main magnet and several secondary magnets. Hydrogen atoms start spinning and generates a small magnetic field. The MRI scanner sends radio waves that are absorbed by the protons. When the radio waves stop, they revert to original orientation whilst releasing energy in the form of radio waves. These are picked up by the receivers
What is the relation between brain surface area and the volume of cortical grey matter?
Brain surface area is directly proportional to the volume of cortical grey matter
What is VBM and what is VBA?
VBM = voxel based morphology
VBA = voxel based analysis
When is high temporal resolution needed and when is high spatial resolution needed in fMRI?
High temporal: rapid brain processes
High spatial: refined localization of function
How does fMRI work?
It measures the surplus of oxygen-rich hemoglobin being supplied to active brain areas. These areas are lighter than oxygen-depleted areas.
The image is made with the subtraction method
What is electro-encephalography (EEG)? How is its resolution and why is it like that?
Technique for functional imaging. Electrodes are placed on the scalp and they measure electric signals from the brain.
High temporal but low spatial resolution. It can measure signals from large numbers of neurons, but not individual ones
–> Fast electricity
–> Disruption electric signal due to skull and surrounding tissue
What is magnetoencephalography (MEG)?
Measures the magnetic fields that are generated by action potentials (electromagnetic induction = electrical field creates magnetic field)
What are the 3 types of information that is picked up by electrodes in EEG?
- Signal from brain tissue closest to it
- Fluctuations caused by electrical rhythms in the brain
- Locations of areas that react to a task can be determined in the brain, even if they’re located more deeply in the brain
What does the fMRI measure?
BOLD response: blood oxygen level dependent response
What are the most costly neuroimaging methods?
PET and (f)MRI
Which neuroimaging methods have the highest spatial resolution?
X ray, CT, MRI, fMRI
PET (a little less though)
Which neuroimaging technique has the best temporal resolution? And which 2 have the lowest temporal resolution?
High: EEG
Low: (f)MRI
Which neuroimaging techniques have low image/data quality? Which ones have high quality?
Low: X ray, CT
High: (f)MRI, PET
What are 2 new methods for analyzing functional neuroimaging data that look at connections between areas?
- Resting state method: seeks correlations between signals from areas
- Mind reading: uses patterns of brain activation to work out what a person is seeing
