the executive brain Flashcards
what is executive function?
control processes that enable
an individual to optimise performance, requiring
coordination of basic cognitive processes
like a conductor
how are EF domain general?
Not tied to a specific cognitive domain
what are the supervisory EFs?
Problem solving
Overcoming habitual responses
Task-switching
Multi-tasking
disorder used be called… but are now linked to…
‘frontal lobe disorders’
prefrontal cortex (PFC)
what are the 3 surfaces of the PFC?
orbital
lateral
medial
what areas within the orbital surface are involved in EF?
BA 11:
- Orbitofrontal/ ventromedial PFC
- Task switching
BA10:
- Polar PFC
- Multi-tasking
what areas within the lateral surface are involved in EF?
BA 46/9:
- Dorsolateral PFC
BA 44/45:
- Ventrolateral PFC
=Problem solving
what areas within the medial surface are involved in EF?
BA 24:
- Anterior Cingulate Cortex
- Overcoming habitual responses
what is the principle of problem solving?
Giving a participant an end-point and a starting point; participants must generate a solution (task setting)
what test is used for problem solving?
Tower test: Tower of London
“how to get from initial to goal position?”
Describe the Ruocco Tower test study for problem solving:
- 38 healthy ps
- trait deliberation: think before act
- fNIRS
- Scarborough adaptation of ToL
what were the results of the Ruocco Tower test study for problem solving?
Increased left dorsolateral PFC activation when solving problems
Even higher in individuals with high trait deliberation
what is a habitual response?
one that we engage in automatically
what concepts are ‘overcoming habitual responses’ related to?
Response inhibition:
- Reducing the likelihood of a particular thought or action
Impulsivity:
- A behavioural tendency to make immediate responses or seek immediate rewards
what tests are used in ‘overcoming habitual responses”?
Stroop test
Go/no go test
explain the Stroop test in terms of habitual response:
reading the word is habitual (fast), so when it is incorrect it must be inhibited
incorrect responses compete with the less habitual task of naming the colour (slow)
describe the Alexander et al. stroop test for ‘overcoming habitual responses’:
- 38 healthy ps
- 42 ps with frontal lesions
- fMRI
- measure reaction time
what were the results of the Alexander et al. stroop test for ‘overcoming habitual responses’?
Slow reaction time and decreased correct responses with lesions in:
anterior cingulate cortex, presupplementary motor area, and dorsolateral areas
what is the go/no go test?
habitual responding is due to frequency of different stimuli
eg. respond habitually when ‘go’ more frequent
what do errors on ‘no-go’ trials show?
measure of response inhibition
behavioural marker of impulsivity
describe the Picton Go/no go test for overcoming habitual responses’:
38 healthy ps
43 ps with frontal lesions
‘go’ was more frequent
what were the results of the Picton Go/no go test for overcoming habitual responses’?
Lesions in superior medial frontal lobe associated with more false alarms:
-Dorsomedial PFC
-Anterior cingulate cortex (ACC)
-Pre-supplementary motor area (pre-SMA)
‘Overcoming habitual responses’: what happens when we make an error?
Humans and non-human primates are slower and more accurate after making an error.
Suggesting: error detection + compensation
what is error-related negativity?
an event-related potential component in EEG detected when an error is made
- relatively large negative deflection in EEG signal
- origins in ACC