Voluntary control over mental processes Flashcards
What are the 2 main aspects of cognitive control?
Evaluative control - ability to monitor your internal and external environments for situations requiring control
Executive control - configure cognitive system in accordance with new demands
What is the “control humunculus”?
Where theorists declare the problem of control extrinsic to their current concern
What cognitive mechanisms have been associated with control?
- Central executive
- SAS - believed to control response to stimuli (utilization behaviour in patients with frontal lobe damage)
What is the modularity hypothesis?
- Idea that the cognitive system consists of a hierarchy of modules with specific functions
- Mentap operations are performed by units in an autonomous manner
How did Fluorens counter the modularity hypothesis?
- Showed that size of lesion has more of an effect than lesion location
- Idea that the whole brain partakes in behaviour - aggregate field theory
What cognitive functions do interference tasks rely on?
`- Basal cognitive action (perception, stimulus response)
- Exectutive functions (goal maintenance)
- Evaluative functions (monitoring for conflicts and errors)
What is spatial stimulus response compatability?
Where it is easier to respond to stimulus when response is on the same side as stimulus
What have stimulus response compatability assays shown us about object and location anaylsis
Dual route model “where” - dorsal stream and “what” - ventral stream
2 separate routes which can facilitate or interfere with eachother
What effect does the stimulus response compatability task have on lateralised motor activation?
Incorrect side is briefly activated before being corrected and becoming more negative
What is the Flanker task?
A number of letter stimuli, must report central. Flanker and central can be compatible or incompatible (task relevant vs task irrelevant information)
What are the results of a stroop task?
- Compatible has lower reaction times than incompatible
- No impact on reading
(indicates automatic word reading vs color processing)
What changes in performance happen after an incorrect response?
- Slower
- More conservative
- Error processing interferes with other processing cs
What effect is observed following errors in a flanker task?
- Reduction of effect after incompatible trisl
- Golton effect - dynamic adjustment of information processing in response to conflict
What effect is observed after incompatible trials in a Simon task?
- Conflict leads to temporary closure of the automatic activation route and therefore reduced effect
- Lack of lateralised readiness potential
What brain area is believed to be especially important with regards to control?
Anterior cingulate cortex
How are different areas of the anterior cingulate cortex believed to deal with different aspects of control?
Rostral - emotive tasks
Dorsal - purely cognitive tasks
What is error-related negativity?
- Error related component which peaks ~100ms after incorrect response
- found over fronto-central electrode sites suggesting ACC origin
What do manipulations of speed-accuracy tasks have on the error-related negativity?
Focus on speed decreases error-related negativity in subject
What effect does error-related negativity have on behaviour?
- Relates to response force, smaller response force (due to inhibition of error motor response) when ERN is large
- Large ERN related to increased probability of pressing the correct key after the wrong one
What is conflict monitoring theory?
Idea that representations are connected via inhibitory links where conflict is defined as a certain Hopfield energy and the energy of the network is the sum of each pair
According to conflict monitoring theory, when is conflict maximal?
- When competing activations are equal
- With large number of competing representations
What are errors in terms of conflict monitoring theory?
Where representation of correct and actual performed response are different, comparison leads to error signal setting of the ACC and possible remedial actions
What evidence suggests that error and conflict are dealt with by two different systems?
- Manipulations for error (flanker task when flankers shown first) shows ERN for errors but not in response to conflict
- Different areas of fMRI activation
What effects on error and conflict are seen in schizophrenics?
- Deficits in error and conflict processing: no post-conflict adjustment and no post-error adjustment
- Reduced ACC activity
How are different brain areas proposed to detect error and control adjustment?
ACC detection - more activity in previous trial
dlPFC - adjustment, more activity in current trial
How has dlPFC been found to act in relation to conflict?
- Selectively activated during preparation for conflict (modified stroop task)
- When activated more results in less conflict
In what other situations is the ACC activated?
- Monetary loss
- Negative feedback
- Social rejection
What have single-cell recordings revealed about the relationship between dopaminergic neurons and the ACC?
After error reduction in dopamine activates D2 indirect dopamine pathway leading to disinhibition of ACC
