Neuropsychology of Executive Function Flashcards
What are executive functions?
Controlling mechanisms of the brain, required for goal-directed behaviour, adaptive responses to novel situations, and regulation of emotion and behaviour
Give examples of executive functions.
▪️Planning
▪️Initiation
▪️Organisation
▪️Inhibition
▪️Problem solving
▪️Self monitoring
▪️Error correction
▪️Cognitive flexibility
What are the two broad categories of clinical executive dysfunction?
▪️Classical ‘cognitive’ executive change
▪️Wider changes involving emotion, social cognition, and reward response
What is the single process model of EF?
All EF processing occurs in the central executive
What is the multiple process theory of EF?
Executive functions comprise of a number of distinct components working together
e.g., sensory perceptual systems, trigger data base, contention scheduling, supervisory attentional system)
What is the supervisory attentional system?
▪️ Proposed action schemas - programmes for the execution of routine behaviours
▪️ Activated automatically in response to environment
▪️ SAS allows for inhibition of automatic responses and activation of appropriate action schema in non-routine situations
What processes are necessary for the SAS?
- Top-down control of action schemas (GDB)
- Monitoring of behaviour
- Specification of a memory trace required for GDB)
- Establishment of future intentions (goal planning, PM)
What can TBI tell us about executive dysfunction?
▪️ No unitary prefrontal syndrome - instead dissociable processes
▪️ Lesions remote from frontal cortex can also cause executive symptoms/failure
According to Stuss and Alexander, what are the three systems of attentional control?
▪️ Superior medial (energising, initiating/sustaining)
▪️ Left lateral (task setting)
▪️ Right lateral (monitoring)
What are the ventromedial and orbitofrontal cortices involved in?
Emotional and behavioural regulation
What are the frontopolar areas associated with?
Integrative/meta-cognitive functioning
What have fMRI and PET studies of EF found?
▪️ Activation is not specific to location nor task
▪️ Generally increases over whole PFC as any task becomes more complex
What is the only cognitive task that is SPECIFIC to dominant frontal lobe function?
Phonemic fluency
What are the main principles to considering when assessing EF?
▪️ Not exclusively frontal lobe function
▪️ Wide heterogeneity of prefrontal areas implicated in different tasks that can change with subtle manipulation
▪️ Frontal lobes mainly about the self
▪️ Multiple processes involved, more dissociation than association
▪️ No problem with test does not mean no problem at all
What is Struss et al’s three-factor model of executive tasks/skills?
- Energisation (process of initiation or sustaining responses, e.g., apathy)
- Task setting (e.g., planning, organising, learning new task)
- Monitoring (e.g., checking, staying on task)