M05 - Executive Control

Question 1

What are executive functions?

Answer 1

• modulate activity of other cognitive functions
• regulatory role

Question 2

Give examples of executive functions

Answer 2

• mentally simulate opponents’ moves
• initiate motor action

Question 3

What are the main brain areas responsible for executive functions?

Answer 3

• Prefrontal cortex
• Parietal cortex region (only the posterior parietal cortex)
• basal ganglia regions

Question 4

What are the symptoms of prefrontal damage?

Answer 4

• normal cognitive function
• difficulty selecting the right action for the current context
  vague and widespread symptoms

Question 5

What is the basic division of executive function?

Answer 5

• Rules (guide human behavior)
• Control (engage rules to a particular context)

Question 6

How can you further divide executive functions, besides rules and control?

Answer 6

• establishing and modifying rules
• contextual control
• working memory

Question 7

What is the syndrome for lateral prefrontal damage?

Answer 7

Frontal dysexecutive syndrome (can’t plan future, do not start new projects, leave tasks incomplete, etc.)

Question 8

What is the syndrome for ventral and medial prefrontal damage?

Answer 8

Frontal disinhibition syndrome (Constant unproductive movement, fail to respond to normal social cues, etc.)

Question 9

How are rules encoded in the brain?

Answer 9

Through activity of populations of prefrontal cortex neurons.

Question 10

What did the single-unit recording of monkeys show about the encoding of new rules in the brain?

Answer 10

Neurons in the prefrontal cortex responded as if they were selective to particular rules, independent of cues or stimuli.

Question 11

How can you study inhibition of rules in the brain?

Answer 11

Through the oddball task (ERP, fMRI)

Question 12

What is the oddball task?

Answer 12

• The stimuli can be visual or auditory.
• The participant is asked to respond whenever a rare, infrequent stimulus (the “oddball”) appears.
• The task measures the participant’s reaction time and accuracy in detecting the oddball.
• It also measures their ability to filter out distractions and maintain attention over time.

Question 13

When and where can you measure the activity of an oddball task?

Answer 13

• 300ms after the onset of the oddball stimulus
• more activity in dorsal lateral part of the prefrontal cortex (dlPFC)
• dlPFC → ability to inhibit rules now and again?

Question 14

What are other examples of inhibiting test tasks?

Answer 14

go/no-go task, stop-signal task

Question 15

What does the Wisconsin Card Sorting test test?

Answer 15

Shifting among rules

Question 16

How does the Wisconsin Card Sorting test work?

Answer 16

• have multiple rules and each might be relevant at a given time depending on the goal
• task: sort the cards (using one of three attributes)
• feedback: correct or incorrect sorting
• participant will use trial and error to get to the currently correct rule for sorting
• people with PFC damage continue to use previously valid rule (Perseveration)

Question 17

How do you test relating rules?

Answer 17

Progressive Matrices Test

Question 18

What is the progressive matrices test?

Answer 18

• task: identify shape that best fits pattern
• especially people with frontopolar cortex damage show deficit here
• people have difficulty relating rules with each other

Question 19

How can you organize the PFC?

Answer 19

Rostro-caudal organization (aka posterior and anterior)

Question 20

What is the Posterior part of the PFC lobes responsible for?

Answer 20

simple functions (e.g. matching behavior to stimuli)

Question 21

What is the Anterior part of the PFC lobes responsible for?

Answer 21

complex functions (e.g. higher order behavioral goals)

Question 22

What are the two theories about the organization of the executive function classification?

Answer 22

• executive function organized according to their level of temporal abstraction (short term vs long term goal)
• executive function organized as a hierarchy (anterior regions shape behavior of posterior regions)

Question 23

What brain region is involved in monitoring the success of behavioral actions?

Answer 23

Anterior Cingulate Cortex (ACC)

Question 24

Why do we think the ACC is involved in monitoring the success of behavioral actions?

Answer 24

• because active in conditions of high conflict
• because it processes feedback

Question 25

Why is working memory involved in executive control?

Answer 25

In order to apply rules and keep them online you have to have them on your mind in that context aka working memory

Question 26

What are the two models of the working memory?

Answer 26

• Baddeley model
• Cowan model

Question 27

Describe the Baddeley model of working memory.

Answer 27

• 3 capacity-limited memory buffers
• control system (central executive that allocates processing recourses to memory buffers)

Question 28

Describe the Cowan model of working memory.

Answer 28

long-term memory representation can remain active state for as long as they are rehearsed