Executive Function COPY Flashcards
What is the default mode network?
It is the brain’s default when it is not engaged in anything (i.e. just sitting still and thinking)
Which part of the brain is crucial for many aspects of cognition?
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
What abilities does executive function include?
- planning and executing behaviour
- sequencing and prioritizing
- estimating, abstracting and projecting
- use working memory to execute a task
- adapt flexibility
- inhibit inappropriate responses
- interact socially in an appropriate manner
What is a metaphor we can use to help us think about what the executive function does?
It is like the CEO of a company; it in of itself does not do the dirty work, but delegates others to the task
Describe some (6) features of goal directed behaviours
- initiation/fluency of behaviour
- creation/maintenance of a task
- sequencing and planning
- modifying behaviours
- self-monitoring and evaluation
- inhibition/resolving interference
Which brain area mediates executive function?
The prefrontal cortex
Which parts of the prefrontal cortex are involved in executive function?
- dorsolateral prefrontal cortex (BA 9, 46)
- inferior prefrontal cortex (BA 11-14)
- medial prefrontal cortex (BA 25-32)
- anterior cingulate cortex
What are some developmental disorders with frontal-striatal pathology?
Schizophrenia, depression, ADHD
What is the mid dorsolateral prefrontal cortex responsible for?
task switching
What is the PMd responsible for?
Response selection
What is the FPC responsible for?
subgoaling
What is the pre-PMd/caudal prefrontal cortex responsible for?
Response-sequence selection
What do prefrontal lesions cause deficits to?
It causes difficulty in divergent thinking
- response is “I don’t know”
What is convergent thinking?
Only one correct answer
What is divergent thinking?
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
Describe the oral/written fluency task
- 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)
What do we see in people who have prefrontal cortex lesions when they perform the oral/written fluency task?
Less output with lesions, and rule breaking (because the rule doesn’t modify behaviour)
What is utilization behaviour?
When object manipulation is not inhibited (?)
What are some components of environmental control of behaviour?
- risk taking
- assessing risks and consequences
- sensitivities to consequences - difficulty inhibiting responses
- stroop task
Why do patients with FPC damage perform poorer on the Stroop task?
Because stimuli are in conflict, and they need to choose the one that is in accordance with their goal
What is the role of the dorsolateral PFC and the inferior frontal junction?
It has a bias towards sensory and perceptual information that is most task relevant
What is the role of the mid dorsolateral PFC?
Selection of information in working memory that is most task relevant
What is the role of the posterior dorsal anterior cingulate cortex?
It resolves competition between potential responses; overrides pre-potent responses
What is the role of the anterior dorsal ACC?
Response evaluation feedback to DLPCF
What is the cingulate cortex responsible for?
- 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 **
What does ERN stand for? When do we observe these?
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
Which brain area takes the longest to develop in humans?
The prefrontal cortex
What does ontology recapitulates phylogeny mean?
Development of more complex brains going down the evolutionary tree (i.e. development is mirrored in species)
- more complex takes more evolution to accomplish
What other brain process is important for executive function?
Working memory
Describe the n-back test?
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
Which brain area becomes very active in the n-back test?
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)
