Executive processes & dysexecutive disorders Flashcards
What are executive functions?
Functions that regulate & control cognitive processing
How do behavioural deficits link to executive functions?
Behaviour deficits stem from difficulties with executive functioning
Name 3 tests of executive processes.
- Tower of Hanoi/London
- Verbal/category fluency task
- WCST
What do you do in the Tower of Hanoi task?
3 rods, one holding a stack of different coloured disks
You must move the entire stack to another rod following numerous rules:
- only move one disk at a time
- a disk can only be moved if it is the uppermost disk on the stack
- no disk may be placed on top of a smaller disk
How do people with frontal lobe damage do on the ToH task?
Have difficulty
Problems with planning (= combining components to complete a task)
Shallice (1982) found that lesions in WHICH area of the brain cause difficulties on the ToH task?
Left anterior lesions
Which researcher/s found that patients with PFC lesions performed worse than health controls on the ToH task?
Goel & Grafman (1995)
Goel & Grafman (1995) say that patients (with PFC lesions) have difficulty on the ToH task not because of planning deficits but because of…
An inability to resolve a goal-subgoal conflict
What does a verbal/category fluency task involve?
Must generate as many words beginning with a letter/in a category
How does damage to the frontal lobe affect performance on verbal/category fluency tasks?
Make less responses than healthy controls (3-4 words per min vs. 12+ words per min)
Repeat words
What did Baldo et al. (2000) find about verbal/category fluency tasks?
People with frontal lobe lesions are impaired (make less responses) compared to healthy controls
The individual does not have an over-learned programme for generating items from a category, so what must they do when doing a verbal/category fluency task?
Must run their own retrieval strategies whilst ensuring that items come from the correct category & aren’t repetitions
What does the WCST test?
A person’s ability to follow rules, use feedback & amend their actions
What does the WCST involve?
There are 4 ‘key’ cards - the participant must match other cards to each key card (depending on colour of shapes, number of shapes on cards, types of shapes on cards)
Pps discover sorting rules using correct/incorrect feedback from the experimenter
What sort of responses do healthy people make in the WCST?
Learn quickly, eventually acquire all rules, make few errors
What sort of responses do people with frontal lobe damage make in the WCST?
They learn the first rule but don’t change - make perseveration errors based on the old rule
What did Nelson (1976) find that patients with frontal lobe damage did on the WCST?
Even when they are told that the rule has changed, they still perseverate
Which researcher/s found that patients with frontal lobe damage were significantly more impaired than patients with non-frontal lobe damage?
Robinson et al. (1980)
What did Robinson et al. (1980) claim the WCST could be used for?
Distinguishing patients with frontal & non-frontal lesions
According to Shallice (2002), patients with frontal lobe damage have an impaired…
Supervisory Activating System
What does a person do/what can a person not do if their Supervisory Activating System is impaired?
Once a strategy has been adopted it keeps running because they can’t interrupt & change their ongoing activity
What happens if there isn’t a well-established current activity & the SAS is damaged?
The system remains inert or is captured by another stimulus
What sort of behaviours do people with a damaged SAS produce?
Distractible & facetious behaviour
Show utilisation behaviour
What is utilisation behaviour?
The presentation of objects implies the order to grasp & use them (Lhermitte, 1983)
What balance is disturbed if an individual is showing utilisation behaviour?
The balance between their dependence on & independence from the outside world is disturbed
When a person is showing utilisation behaviour, what inhibitory function is suppressed?
The inhibitory function of the frontal lobes on the parietal lobes is suppressed
Who proposed the SAS model?
Norman & Shallice (1986)
According to the SAS model, which 2 processes manage the functioning & control of schemas?
- Contention scheduling system
2. Supervisory activating system