Hoofdstuk 15 Flashcards
Executive Functions
The complex processes by which an individual optimizes her performance in a situation that requires the operation of a number of cognitive processes (PFC)
Homunculus Problem
klein mannetje in je hoofd
Prefrontal Cortex
1) Lateral Surface - anterior to premotor areas, Brodmanss area 6 and Frontal EyFields (Brodmans area 8) - closest to skull
2) Medial Surface - Between 2 hemispheres, front of Corpus Callosum and Anterior Cigngulate Cortex
3) Orbital Surface (above orbits of the eyes and nasal cavity)
Lateral - sensory inputs (visual, auditory, somatosensory)
Medial/orbital (long tterm memory processing emotion)
Preseveration
Failure to shift away from a previous response
Task Switching
discarding a previous schema and establishing a new one
Switch Cost
Difference in reaction time between switch and non-switch trials
* reflect suppressing the old task or reflect setting up the new task
Multi-tasking
carrying out several tasks in succession; requires both task-switching and maintaining future goals while current goals are being dealt with
SAS - Superrvisory Attentional System
- task & behaviors (schemas)
- biasing mechanism that activates/surpresses the schemas
Biasing influence
make certain behaviour more/less likely
Principle of organisation of executive functions
- distinction between the control of affective or reward-related Stimuli (HOT) vs. purely cognitive (COLD) stimuli
- HOT cognitive control involves primarily the orbiofrontal cortex + associated ventromedial prefrontal cortex
- CoLD Cognitive Control = primarily the lateral PFC
Damasio Somatic marker Hypothesis
form the link between previous situations stored throughout the cortex and the “feeling” of those situations stored in regions of the brain dedicated to emotion (amygdala) and the representation of the body states (e.g. the insula)
- Somatic Markers in the ventromedial frontal cortex - incl. parts of orbital surface- and have a direct role in controlling ongoing behaviour, when feelings are critical
Multiple Demand Network
a set of brain regions in the lateral prefrontal and parietal lobes activated by a large range of tastes relative to baseline
Executive Functionss - 2 regions
1) those requiring control or evaluation of affectively loaded stimuli (requiring orbitofrontal and ventromedial cortex)
2) those requiring control or evaluation of non-affective stimuli (requiring lateral PFC)
Fuid intelligencce
flexible thinking and problem-solving in novel situations, independent of acquired knowledge (Raven’s Matrices)
Crystallized Intelligence
ability to use prior expertise and knowledge (WAIS)
Koechlin & Summerfield hierarchy
posterior premotor cortex - frontal poles (anterior)
* highest level in their model is “branching control”; involves holding in mend pending tasks, while carrying out an ongoing task
Frontal Pole Region
BA10
Stuss:
Hemispheric specialization of Executive Functions
* left Lateral PFC = relatively specialized (longer switch cost for task-setting)
* right lateral PFC = task monitoring (error prone)
Monitoring = relating information currently held in mind back to the task requirements (is the received info valid?)
Sustained Attention = maintaining focus on the task requirements over a period of time
Anterior Cingulate Cortex (ACC)
lies above the Corpus Callosum on the medial surrface of each hemisphere
- detection of errors
- Error-related Negativity = an event-related potentional component in EEG that can be detected at the scalp when an error is made
Executive Functions neeeded to optimize performance
- several cognitive processes need coordination
- situation is novel/difficult
- trouble-shooting/problem-solving
(supervisory/controlling)
Keyrole: PFC
Legions: problems with problem sovling, multi-tasking, overcoming habitual responses
Orbitofrontal+ventromedial PFC
strong connections with regions processing emotions
Lateral + dorsal medial PFC
sensory + motor regions
