Topic 2: Intro to Neuropsychological Assessment Flashcards
Case of HC
- Neurocommuncation is all electrical = activation can become out of control will may result in seizures
- Suffered seizures from birth to age 5
- Distorted speech
- LEFThemispherectomy at 5 yrs abated seizures after 3 months – minimized immediately
- Lost sight in RIGHT VF (very unlikely that the brain will adapt to this as the visual system develops early): no neglect (full attentional ability)
- Although language is left hemi dominant; this individual did not experience language inabilities
- Motor deficient: Limp with RIGHT leg: preserved right side control – LEFT-handed (left hemi is heavily associated with language (left hemi dominated); except in left-handed individuals)
- 15 yrs – high verbal IQ
- 21 yrs – graduated from university
- 27 yrs – high functioning corporate executive
Hemispherectomy
“No brain is better than no brain.” A hemispherectomy is a radical surgical procedure where the diseased half of the brain is completely removed, partially removed and fully disconnected or just disconnected from the normal hemisphere.
- recall the contralateral relationship between the brain and body
- plasticity plays a role in how well the brain accommodates to a procedure like this (age, plasticity)
- can include the cortex and medial structures
- a left hemispherectomy does not include the left side of the cerebellum
FAST Acrynom for Stroke
- (FACE) Do you notice one side of their face drooping? Ask the person to smile.
- (ARMS) Are they experiencing weakness in one arm? If they raise both arms, does one drift down?
- (SPEECH) Is speech slurred, are they unable to speak or are they hard to understand? Ask the person to repeat a short sentence like, “Remember the Alamo.” Do they repeat the sentence correctly?
- (TIME TO GET HELP) If you notice any of these symptoms, call 911 and get the person to a hospital immediately.
- timing (did these symptoms arise suddenly?)
Premorbid Function
Premorbid functioning and adjustment refer to an individual’s social, interpersonal, academic, and occupational functioning before the onset of psychotic symptoms.
Premorbid functioning refers to the level of functioning prior to some pathological event. Some knowledge or estimate of premorbid functioning is important in order to draw conclusions regarding whether the obtained test scores reflect some decline from prior or premorbid levels.
Premorbid Function: Low Functioning
Risk of misattributing low scores to injury.
“Low functioning” in terms of premorbid function refers to a state in which an individual was functioning at a lower level prior to the onset of a disease or condition. For example, someone with a low premorbid functioning level may have had difficulty with everyday tasks such as bathing, dressing, and grooming before the onset of a condition like dementia.
Premorbid Function: High-Functioning
Risk of overlooking a dysfunction due to compensatory strategies
Mass Action
The principle of mass action states that the ability to perform a particular task or recall information is not localized to a specific area of the brain, but is instead a result of the collective activity of many neurons distributed throughout the brain.
- Karl Lashley (1920’s)
- Search for engram using rats (failed)
- memory instead works more like a network; there is no single location in the brain where memory is housed (the hippocampus is not an engram)
What do the terms “equipotentiality” and “plasticity” refer to when speaking about mass action?
“Equipotentiality” refers to the idea that different brain regions have the potential to take over the functions of other regions in case of injury or damage. This means that if one part of the brain is damaged, other parts can compensate for the lost function.
“Plasticity” refers to the ability of the brain to change and adapt in response to experience, injury, or other types of stimulation. Plasticity is thought to be an important mechanism for the brain to recover from damage and to learn and acquire new information.
When speaking about mass action, equipotentiality and plasticity are important concepts because they suggest that the brain has the capacity to reorganize and compensate for damage, and that different brain regions may be able to perform similar functions if necessary.
Engram Endeavour Result
Lashley could not find a specific location in the brain responsible for a specific task (an engram) which resulted in this conclusion of mass action.
The idea of mass action is like a snapshot of the activity of neurons in the brain when you experience something new or learn something. When you have a new experience, the neurons in your brain start firing, or sending signals to each other, in a specific pattern. This pattern of activity is thought to represent the memory or information that you’ve learned.
The theory is that when you form a new memory, changes occur in the connections between neurons in your brain, allowing the memory to be stored as a sort of “snapshot” of the activity of neurons at the time. When you want to recall the memory later, your brain can “play back” this snapshot, and the neurons fire in a similar pattern to when the memory was first formed. This reactivates the memory and allows you to recall it.
What is the difference between the ideas “mass action” and “locus/engram?”
The difference between the ideas of “mass action” and “locus” is that “mass action” refers to a theoretical representation of a memory or information stored in the brain, while locus/engram refers to a specific location in the brain associated with a particular function or ability.
Explain the belief “that extent of damage is more important than locus.”
The idea of “mass action” relates to the belief that the extent of damage to the brain is more important than the locus, or specific location, of the damage in 2 main ways:
1. First, the concept of mass action suggests that memories are not stored in a specific, localized area of the brain, but are instead distributed throughout the brain, with each memory represented by changes in the connections between neurons. This idea is in line with the belief that the extent of damage to the brain is more important than the locus of the damage, as it suggests that memories can be stored redundantly across multiple areas of the brain, so that even if one area is damaged, the memory may still be intact in other areas.
2. Second, Lashley’s work on the principle of mass action showed that the ability to perform a particular task or recall information is not dependent on the activation of a single, specific area of the brain, but is instead a result of the collective activity of many neurons.
Locationization of Function
Penfield’s work suggested that the brain has a sort of “map” or organization, with different areas of the brain responsible for specific functions, such as vision, hearing, and movement.
- Surgical patients (Penfield): electrical stimulation on the brain while the patient is awake (no pain receptors in the brain) and ask the patients what they are experiencing
- Non-human animal studies: Anterior intraparietal (AIP) sulcus lesions in macaques lead to the inability to pre-shape hands during grasping
- functioning mapping: electrical grades and lesions help to create
- demonstrates the localization of function
How was the theory of “localization of function” developed?
Penfield used electrical stimulation to study the cortex and determine which areas of the brain were responsible for specific functions.
- Placed electrodes on the surface of the brain and stimulate different areas while patients were conscious and under local anesthesia.
- By observing the patient’s reactions and responses to the stimulation, he was able to determine which areas of the cortex were responsible for particular functions.
- Approach allowed him to create detailed maps of the cortex, known as Penfield’s homunculus, which showed the areas of the brain responsible for different functions such as sensation, movement, and speech.
Anterior intraparietal (AIP) sulcus
The anterior intraparietal (AIP) sulcus is a sulcus, or groove, located in the human brain. AIP sulcus plays a role in the planning and execution of hand movements.
- part of the parietal cortex, which is a region of the brain involved in sensory processing and spatial awareness.
- Thought to be involved in processing visual information related to reaching and grasping movements.
- Studies have shown that the AIP sulcus is activated when a person reaches for and grasps objects, and damage to this area can result in difficulty with these movements.
Penfield’s homunculus
- Penfield’s homunculus is a map of the human cortex or outer layer of the brain, that shows the relative size and location of different areas responsible for different functions.
- The homunculus shows the areas of the cortex responsible for different functions, such as sensation, movement, and speech, represented as different parts of the body. For example, the face and hands are shown as disproportionately large, reflecting a large amount of cortex dedicated to processing sensory information from these areas.
- The term “homunculus” comes from the Latin word for “little man,” and the map is often depicted as a stylized figure with distorted body parts that reflect the relative size of the areas of the cortex responsible for different functions.
Example of “Localization of Function” in primates:
Anterior intraparietal (AIP) sulcus lesions in macaques lead to the inability to pre-shape hands during grasping.
Studies in non-human primates have shown that the AIP sulcus contains a high density of neurons that are involved in processing visual information related to objects. These neurons respond to the sight of objects, their location in space, and their movement. The activity of these neurons is thought to play a critical role in the planning and execution of reaching and grasping movements.
Describe the surgical treatment HM had undergone and how it relates to the theory “localization of function:”
In HM’s case, his seizures were so severe and frequent that they severely impacted his quality of life. To help him, doctors decided to perform a surgical procedure called a bilateral medial temporal lobe resection, which involved removing the hippocampus and surrounding tissue from both sides of his brain. The surgery aimed to remove the source of his seizures in the hopes that this would reduce or eliminate them.
The medial temporal lobes contain structures such as the hippocampus and amygdala, which are important for memory and emotional processing. Therefore, the removal of these structures can result in significant changes in memory and emotional functioning.
Removing the source of HM’s seizures was believed to result in a cure. Unfortunately, the surgery had unintended consequences, and HM ended up with significant memory problems as a result.
Surgery was used as a method to resolve the issues of Henry Molaison (also known as HM), who was a famous patient with epilepsy, because of the belief that the seizures he was experiencing were originating from a specific, localized region of his brain. This belief was based on the then-prevailing understanding of the localization of function in the brain, which held that different areas of the brain were responsible for specific functions, such as vision, hearing, memory, and so on.
The Modularity of Mind (Jerry Fodor)
The basic idea of modularity is that the mind is composed of a number of separate and distinct modules or processing systems, each with its own specialized function. These modules are thought to be specialized for specific types of processing, such as perception, language, and reasoning.
- Modules are informationally encapsulated, meaning that the information processed by one module is not available to other modules. (e.g., lower-level sensory systems): These are processes that are Essential, automatic, very fast, highly specialized systems.
- Modules are domain-specific, meaning that they are specialized for processing information in a specific domain, such as language or vision.
- E.g., Face recognition? - there are regions in the brain that are activated when there is a face-like stimulus in our environment
The Modularity of the Mind Analogy
Imagine that your mind is like a big toolbox with different tools inside. Each tool is good at doing a specific job, like seeing, hearing, speaking, or counting. These tools are like modules in your mind that are designed to help you do different things.
For example, you have a tool in your mind that helps you see things. This tool is called the “seeing module.” When you look at something, this tool starts working and helps you see what it is. You also have a tool in your mind that helps you hear things. This tool is called the “hearing module.” When you listen to someone talking, this tool starts working and helps you understand what they’re saying.
Just like how you can’t use a hammer to screw in a nail, the different modules in your mind can’t help each other out with their own jobs. Each module is like its own little toolbox that only works on its own specific task.
Brain Lesion
A brain lesion is an area of abnormal tissue in the brain, caused by injury, disease, or abnormal growth. Lesions can be located in any part of the brain, and can be of different sizes, shapes, and types. Brain lesions can be caused by a variety of factors, and can take many forms. Here are some common examples:
- Infarction
- Hemmorrhage
- Tumor
- Trauma
- Degenerative Disease
etc…
Closed Head Injury
- Normally results in a contusion or a concussion.
- Normally caused by a quick acceleration/deceleration: the brain will continue to move in the skull when hit; the speed determines how much movement and damage the brain undergoes.
- I.e., the head sustains a blunt force trauma, such as from a fall, a blow to the head, or a car accident, but the skull remains intact and there is no open wound.
Concussion
A temporary loss of brain function caused by a brief disturbance of brain activity. Concussions can result in symptoms such as confusion, headache, dizziness, and memory problems.
Contusion
Bruises on the brain, and diffuse axonal injury, which is damage to the brain’s nerve fibres. These types of injury can result in more severe symptoms, such as loss of consciousness, long-term memory problems, changes in personality and behaviour, and difficulty with physical or cognitive tasks.
- serious, long-term damage
- Contusions often require medical treatment, and in severe cases may lead to permanent brain damage.
Cerebral Oedema
Cerebral edema is a medical condition in which the brain swells and increases in size due to the accumulation of fluid. This swelling can put pressure on the brain and cause it to be compressed within the skull, leading to a range of serious and potentially life-threatening complications.
Infarction
Neuronal necrosis due to loss of blood supply; Infarction is a medical term that refers to the death of tissue due to a lack of blood flow. In the context of the brain, an infarction is commonly referred to as a stroke or a cerebral infarction.
How would you treat an ischemic stroke?
In the case of an ischemic stroke, which is caused by a blood clot blocking blood flow to the brain, the goal of medical treatment is often to thin the blood and break up the clot. This can be done by administering medications known as thrombolytics, such as tissue plasminogen activators (tPA), which are designed to dissolve blood clots.
Stroke
Sudden loss of blood supply.
Double Dissociation (WRITTEN RESPONSE POTENTIAL)
Double dissociation is a term used in neuroscience to describe a situation in which two groups of patients have distinct patterns of cognitive impairment that suggest different neural substrates are responsible for different cognitive processes.
The idea is that, if two cognitive processes are truly distinct and rely on different neural systems, then damage to one of those systems should impair one process but not the other. Conversely, damage to the other system should impair the other process but not the first. This pattern of findings is referred to as a double dissociation.
For example, consider two cognitive processes, A and B. If a patient with damage to the neural system responsible for process A shows impaired performance on task A but not task B, and a patient with damage to the neural system responsible for process B shows impaired performance on task B but not task A, this would be considered a double dissociation.
Summary:
- Lesion A results in a Deficit A but NOT Deficit B
- Lesion B results in a Deficit B but NOT Deficit A
- e.g., Wernicke’s & Broca’s Aphasias (Comprehension vs Output); demonstrate that the two areas are independent of each other
- e.g, damage in the dorsal and ventral stream: determining where something is in space and determining what the object is
Importance of Multiple-Case Studies
Viability in groups; it is important to look at multiple types of tests, subjects, etc. Cannot make sweeping generalizations.
For example, a single-case study of an individual with brain damage might suggest a specific relationship between the damage and a particular behavior or cognitive function. However, without additional studies of other individuals with similar damage, it is difficult to know whether the relationship observed in the single case is specific to that individual or is a more general phenomenon. By studying multiple cases, researchers can gain a better understanding of the common patterns that emerge across different individuals and can identify the key factors that contribute to the brain-behavior relationship. This can lead to a more robust understanding of the neural substrates that support different cognitive functions and can inform the development of new treatments for neurological and psychiatric disorders.
Example: (figure)
NS - Normal Subjects
AMN - Anterograde Amensics
AD - Alziehers dementia
HD - Huntington’s disease
Graph A: Recognition Memory
Graph B: Priming: implicit memory
Mini-Mental State Exam (MMSE)
The Mini-Mental State Exam (MMSE) is a commonly used screening tool to assess cognitive function, specifically the level of impairment in several domains such as orientation, memory, attention, language, and calculation. The MMSE is a brief, structured test that can be administered in about 10-15 minutes and is often used in clinical settings, such as in a doctor’s office or a hospital, to help diagnose cognitive problems or to monitor changes in cognitive function over time. The MMSE score can range from 0 to 30, with lower scores indicating greater cognitive impairment.
Trail Making Test
The Trail Making Test is a neuropsychological test of visual attention and task switching. It consists of two parts in which the subject is instructed to connect 25 dots as quickly as possible while maintaining accuracy. The test can provide information about visual search speed, scanning, processing speed, mental flexibility, and executive functioning. It is sensitive to detecting cognitive impairment associated with dementia, for example, Alzheimer’s disease.
- The test was created by Ralph Reitan (Halstead-Reitan battery)
- Trail making (2 levels): first time with 25 numbers only, then the second time with 13 numbers and letters A -L
Rey Complex Figure
The Rey–Osterrieth Complex Figure (ROCF) test is a commonly used neuropsychological assessment tool. It is widely used to assess the visuo-constructional ability and visual memory of neuropsychiatric disorders, including copying and recall tests.
Raven Progression Matrices
Raven’s Progressive Matrices (often referred to simply as Raven’s Matrices) or RPM is a non-verbal test typically used to measure general human intelligence and abstract reasoning and is regarded as a non-verbal estimate of fluid intelligence.
Judgment of Line Orientation Test
Judgment of Line Orientation (JLO) is a standardized test of visuospatial skills commonly associated with functioning of the parietal lobe in the right hemisphere. The test measures a person’s ability to match the angle and orientation of lines in space.
Dot Localization Task
Comparison/Differences between Experimental Psychology and Neuropsychology Assessment
