Neuropsychology Flashcards
What is neuropsychology?
The study of people with brain damage due to injury, disease/illness or surgery in order to map structure of the brain.
Recently the definition has been expanded to include the biological substrates of psychological disorders e.g., depression.
What are 2 pros of neuropsychological studies?
- Can show which brain areas are necessary for a particular function.
- Can show us what processes are unitary, and might be made up of separable sub-processes.
What can neuroimaging studies tell us?
Which regions seem to be active during cognitive processes, but cannot allow conclusions to be drawn about causation.
What are 4 cons to neuropsychological studies?
- Normally look at single case studies - individual difference in performance could be a confounding factor.
- The brain may change the way it functions, or its structure, to compensate for damage to particular structures (plasticity).
- When only measure functions have been lost, the results = only be as reliable and specific as the tests used.
- Brain damage is rarely neat - most of the time damage won’t be restricted to one structure, or only a portion of a structure.
What can conditions can cause Amnesia?
What area is damaged?
- head injury
- Severe hypoxia (carbon monoxide poisoning / cardiac arrest)
- Herpes encephalitis
- Wernicke-Korsakoff syndrome
- Transient global amnesia
- Transient epileptic amnesia
Damage to wither the medial temporal lobes or the basal ganglia.
What are the 6 main features of amnesia?
- Pronounces anterograde amnesia (inability to remember info acquired after the onset of amnesia).
- Variable retrograde amnesia (inability to remember information acquired before the onset of amnesia).
- Intact working memory (e.g., digit span).
- Preserved general intelligence (IQ)
- Skills such as driving and music are unaffected
- Some residual learning capacity remains.
What causes Korskoff’s syndrome?
Result of long-term alcoholism.
What are the 5 main symptoms of Korskoffs syndrome?
How do symptoms appear?
- Anterograde and retrograde amnesia.
- Confabulation (patient glibly produces plausible stories about past events rather than admit memory loss).
- Meagre content in conversation.
- Lack of insight
- Apathy (patients lose interets in things quickly and are indifferent to change)
Symptoms appear suddenly, within the space of a few days.
What causes Korsakoff’s syndrome?
Thiamine (Vit B1) deficiency with a prolonged intake of excessive alcohol.
Can Korsakoff’s syndrome be treated?
Yes, with massive doses of vitamin B1, but cannot be cured and has poor prognosis.
What produces time-dependent retrograde amnesia?
Traumatic brain injury
What determines how far back a patient with retrograde amnesia memory is lost?
The severity of the injury, as it heals the memory will return.
Duration of post-traumatic amnesia: What did Whitty & Zangwill (1966) find in patients with severe head injuries?
- 10% had duration of less than 1 week.
- 30% had duration of 2-3weeks.
- 60% had duration of more than 3 weeks.
Sometimes isolated events, e.g., visit of a relative, are retained as island memories.
Give a brief overview of Henry Molaison case study.
What part of the brain was removed?
What were the results?
HM had a large bilateral portion of the medial temporal lobe removed, including the hippocampus (for epilepsy treatment).
His STM was relatively unchanged but he was unable to make new memories (anterograde amnesia). Normal attention and working memory capacities; could hold items in mind while rehearsing them. But unable to store this in the LTM. Implicit memory remained intact.
What is anterograde amnesia?
The inability to make new memories.
Explicit-implicit dissociation in amnesia: give an overview of Graf et al., (1984) use of explicit and implicit instructions.
- What did the participants do?
- What was the implicit instruction (condition)?
- What was the explicit instruction(condition)?
- Made a liking rating of the study list words (dislike extremely - like extremely).
- Complete stems with first word that comes to mind.
- Complete stems with words from the liking-rating task.
Give an overview of case study L.H. (double dissociation of HM vs LH).
What brain damage did he have?
What was removed?
What were the results?
Severe closed-head injury at age 18. Severe damage to parietal and occipital lobe.
Right temporal lobectomy. Removal of right inferior temporal gyrus. fusiform gyrus.
LH could not recognise faces, but could recognise people by the sound of their voice. Impairments were mainly visuoperceptual.
What is the system consolidation theory (Squire & Bayley 2007)?
What does this explain regarding older memories?
- The hippocampus consolidates new memories, when consolidation is complete they are stored elsewhere in the brain e.g., neocortex.
- Explains why older memories tend to survive hippocampal damage - they have been transferred elsewhere for storage, whereas newer memories are more likely to be lost.
What is the reconsolidating theory (Tronson & Taylor 2007)?
- Memories will rarely consist of a single trace or neural substrate. We frequently recall memories, think about them, and discuss them. Each time a memory is used, it is reconsolidated; each use of emory is associated with a new phase of storage, resulting in many different traces for the same event.
This means that the frequency of use of a memory will contribute to the extent of the amnesia.
