executive functions (week 6)

Question 1

what are executive functions?

Answer 1

executive functions coordinate other brain modules to enable flexible, purposeful, goal-directed behaviour - they are needed to optimise performance in situations that require coordination between several cognitive processes

Question 2

what are the three surfaces of the prefrontal cortex and what processes are they implicated with?

Answer 2

lateral - implicated in “cold” control processes (cognitive aspects)
medial and orbital - implicated in “hot” control (emotional/social regulation of behaviour)

Question 3

what are the five general situations that require executive functions (Norman & Shalice, 1986)?

Answer 3

1. situations involving planning or decision making
2. situations involving error correction or troubleshooting
3. situations where responses are not well-learned or contain novel sequences of actions
4. situations judged to be dangerous or technically difficult
5. situations that require the overcoming of a strong habitual response or resisting temptation

Question 4

what problems does damage to the prefrontal cortex cause in regards to the wisconsin card sorting test?

Answer 4

patients with prefrontal cortex damage fail to update the rule changes and exhibit preservation behaviour i.e., they keep responding using a previously correct response

Question 5

what did Monchi et al, (2001) find out about the ventrolateral prefrontal cortex (VLPFC)?

Answer 5

it is related to rule changes and is most strongly activated for negative feedback, suggesting this region is involved when there is a need to change the rule

Question 6

what is the role of the anterior cingulate (ACC) in executive functions?

Answer 6

1. detection of errors and detection of response conflict
2. stroop test: functional imaging and lesion studies suggest involvement of anterior cingulate cortex (ACC)

Question 7

what is pretrides’ (2000) theory of working memory?

Answer 7

1. assumed division of prefrontal cortex into at least to separate processes - maintenance (retention) and manipulation (updating)

Question 8

what is the evidence for functional specialisation within PFC?

Answer 8

1. firth (2000): left DLPFC may be responsible for selecting a range of plausible responses - “sculpting the response space”/task-setting
2. firth et al. (1991): left DLPFC active in “free will” - choosing which fingers to move or which word to say vs. being told what to do

Question 9

functional specialisation within the prefrontal cortex: right dorsolateral PFC

Answer 9

may be important in monitoring and sustained attention, both for externally presented information (perception tasks) and internally generated information (memory tasks) - activity greatests in conditions of uncertainty

Question 10

what doe unitary accounts argue about executive functions?

Answer 10

unitary accounts argue that there are no ‘executive functions’, just one general underlying function
- in support of this, patients’ performance on many tests of executive function are correlated with each other, and with fluid intelligence (Roca et al., 2010)

Question 11

what is the multiple-demand network (unitary accounts)?

Answer 11

evidence for a single set of fronto-parietal brain regions called the multiple demand network that is active during all tasks that we consider to involve executive functions (Duncan and Owen, 2000)