Executive Function

Question 1

What is the default mode network?

Answer 1

It is the brain’s default when it is not engaged in anything (i.e. just sitting still and thinking)

Question 2

Which part of the brain is crucial for many aspects of cognition?

Answer 2

The frontal lobe
- people with frontal lobe damage perform as well on IQ tests than people without lesions, but do poorly on cognitive tasks like the MocA

Question 3

What abilities does executive function include?

Answer 3

1. planning and executing behaviour
2. sequencing and prioritizing
3. estimating, abstracting and projecting
4. use working memory to execute a task
5. adapt flexibility
6. inhibit inappropriate responses
7. interact socially in an appropriate manner

Question 4

What is a metaphor we can use to help us think about what the executive function does?

Answer 4

It is like the CEO of a company; it in of itself does not do the dirty work, but delegates others to the task

Question 5

Describe some (6) features of goal directed behaviours

Answer 5

1. initiation/fluency of behaviour
2. creation/maintenance of a task
3. sequencing and planning
4. modifying behaviours
5. self-monitoring and evaluation
6. inhibition/resolving interference

Question 6

Which brain area mediates executive function?

Answer 6

The prefrontal cortex

Question 7

Which parts of the prefrontal cortex are involved in executive function?

Answer 7

1. dorsolateral prefrontal cortex (BA 9, 46)
2. inferior prefrontal cortex (BA 11-14)
3. medial prefrontal cortex (BA 25-32)
   
   • anterior cingulate cortex

Question 8

What are some developmental disorders with frontal-striatal pathology?

Answer 8

Schizophrenia, depression, ADHD

Question 9

What is the mid dorsolateral prefrontal cortex responsible for?

Answer 9

task switching

Question 10

What is the PMd responsible for?

Answer 10

Response selection

Question 11

What is the FPC responsible for?

Answer 11

subgoaling

Question 12

What is the pre-PMd/caudal prefrontal cortex responsible for?

Answer 12

Response-sequence selection

Question 13

What do prefrontal lesions cause deficits to?

Answer 13

It causes difficulty in divergent thinking

- response is “I don’t know”

Question 14

What is convergent thinking?

Answer 14

Only one correct answer

Question 15

What is divergent thinking?

Answer 15

No single correct answer, therefore it requires a strategy to generate an alternative

ex. what is the best paying job in North America?
- response is based on weighing pros and cons of each possible answer

Question 16

Describe the oral/written fluency task

Answer 16

• makes people list as many words as they can under a defined set of rules (ex. beginning with c, only 4 letters, etc) in 60 seconds
• requires strategies to succeed, while inhibiting socially inappropriate behaviours (you have to monitor your behaviour to see if you are reaching the goal)

Question 17

What do we see in people who have prefrontal cortex lesions when they perform the oral/written fluency task?

Answer 17

Less output with lesions, and rule breaking (because the rule doesn’t modify behaviour)

Question 18

What is utilization behaviour?

Answer 18

When object manipulation is not inhibited (?)

Question 19

What are some components of environmental control of behaviour?

Answer 19

1. risk taking
   - assessing risks and consequences
   - sensitivities to consequences
2. difficulty inhibiting responses
   - stroop task

Question 20

Why do patients with FPC damage perform poorer on the Stroop task?

Answer 20

Because stimuli are in conflict, and they need to choose the one that is in accordance with their goal

Question 21

What is the role of the dorsolateral PFC and the inferior frontal junction?

Answer 21

It has a bias towards sensory and perceptual information that is most task relevant

Question 22

What is the role of the mid dorsolateral PFC?

Answer 22

Selection of information in working memory that is most task relevant

Question 23

What is the role of the posterior dorsal anterior cingulate cortex?

Answer 23

It resolves competition between potential responses; overrides pre-potent responses

Question 24

What is the role of the anterior dorsal ACC?

Answer 24

Response evaluation feedback to DLPCF

Question 25

What is the cingulate cortex responsible for?

Answer 25

• selection of appropriate responses
• resolution of conflict (correct vs. incorrect response)
• activated in stroop

** THE ANTERIOR CINGULATE MONITORS THE EXTENT TO WHICH THE RESPONSE MATCHES THE GOAL, AND HOW IMPORTANT IT IS THAT IT MATCHES **

Question 26

What does ERN stand for? When do we observe these?

Answer 26

error-related negativity; it spikes when we know we’ve made an error
- Fellows and Farah study: if the task is speed, there is a low ERN (the wrong response it not related to the goal); if the task is neutral, there is some ERN spike; if the task is accuracy, the ERN spike is large, because the right response is needed

Question 27

Which brain area takes the longest to develop in humans?

Answer 27

The prefrontal cortex

Question 28

What does ontology recapitulates phylogeny mean?

Answer 28

Development of more complex brains going down the evolutionary tree (i.e. development is mirrored in species)
- more complex takes more evolution to accomplish

Question 29

What other brain process is important for executive function?

Answer 29

Working memory

Question 30

Describe the n-back test?

Answer 30

Subjects are asked to match current number with n number of words back
ex. a two back requires that subjects match 4 with 4 in the sequence 4 7 4 8

Question 31

Which brain area becomes very active in the n-back test?

Answer 31

the dorsolateral prefrontal cortex, but only with increasing difficulty (ex. 1 back is fine, but 6 back is extremely active)
- damage to the DLPFCx cannot inhibit incorrect responses on Wisconsin sorting task (even though they know it is the wrong answer)