Task2: Cognition
Miller et. al
stimulus-response mapping
PFC: 2-way connections to all sensory neocortical and motor cortices and range of subcortical structures. Asserts top-down influence on a wide range of brain processes
lateral: extends to inferior frontal sulcus (working memory)
medial: extends to cingulate cortex (MCC)
Functions:
Cognititve control over goal-directed behavior (exciting stimulus-response mapping points[associations])
Maintenance (working memory and task rules: biasing other brain areas towards task-relevant information)
Controls lower sensory, memory and motor operations for common purpose
task contingencies
lateral PFC - interconnected with higher-order sensory and motor cortex. Also indirectly connected with Limbic system, processing internal info like reward.
Damage: irresponsibility, stimulus-driven life, distractibility, impulsivity
Wisconsin Card task (sort cards acorindg to figure, card or number) and PFC damage - can learn 1st rule and then cant switch it
mechanisms- dopamine influx into PFC, gating signal strengthening association at a given time,
biased competition model
Passingham et al.
VLPFC= working memory (showed by sustained activity)
sustained activity (maintenance of sensory information, response preparation, transformation of sensory input to response, task rules)
reward expectancy
Lateral PFC stimuli-outcome association
OFC = reward expectancy
PFCs sustained activity is related to cognitive controll of all the elements needed in task execution
Xu, Y et. al
Study - presented subjects with pictures of faces and houses and attend either to houses/faces (pics were overlaping)
Fusiform face area - faces
parahippocampal place area (PPA) = houses
both of these regions were more active when attending to face (for FFA) or house (for PPA)
Inferior frontal junction area (IFJ) responded regardles whether it was house or face- provided FFA/PPA with constant lag of 20ms. IFJ is reponsible fo flexibility in attentional selection of different objects appearing on the same spatial location
Bunge et al.
Abstract rules
STUDY
H: test whether DLPFC and VLPFC or both would be implicated in retrieving/maintaining abstract rules
method: association of 4 verbal with4 nonverbal cues and 4 rules, and were asked if all of them were either correct or incorrect
RESULTS:
Left VLPFC, Parietal cortex and pre-SMA were sensitive to rules
VLPFC retrieves semantic info associated with a cue from left temporal cortex. then interacts with parietal cortex to retrieve and maintain relevant response contingencies
AREA 46 = (DL PFC) response preperation, transformation fron sensory input to response
AREA 48 - (maintenence)
conjunctiv tunint -cooperation between diffrernet brain areas
SPL- voluntary switching of attention
compound vs simple rules
the more complex rule - bigger activation in frontal polar cortex
DLPFC actie only for complex stuff