control of cognition Flashcards
what organises domain specific modules?
control mechanisms select and activate a subset of processing modules
organise them to accomplish tasks
what is meant by ‘task-set’?
how are they selected?
appropriate organisation of perceptual, cognitive and motor resources to carry out a task
selected by environment or at will
examples of functions of executive control?
inhibiting actions
managing LTM search
coordinating aspects of multitasking
select mental resources required to perform a task
what is meant by control by the homunculus?
unitary inner central executive control agent
little man inside head
who came up with the idea of the ‘central executive’?
baddeley and hitch in working memory alongside visuo-spatial scratchpad and phonological buffer
what did norman and shallice deduce about ‘central executive’?
who argued with this and what did they say?
supervisory attentional system to choose between processes
gilbert and burgess argued it was fractioned
what are several ways to investigate control processes?
- observation of -
* pathological failures after brain damage
* everyday failures of control (action errors) - behavioural experiments
- measure brain activity correlated with exercise of control functions
describe studying errors of control in everyday life to investigate control processes (action errors)?
how studied?
examples of 3 specific errors?
systematic analysis of errors from diary studies and accident enquiries
e.g
capture error - habitual action pattern seizes control of behaviour
cross-talk error - failure to keep separate elements of concurrent tasks apart e.g dual-task
lost intentions - failure to initiate intended action when trigger conditions in prospective memory occur
describe studying pathological failures after brain damage to investigate control processes?
example?
4 different types of control process impairments after brain damage?
e.g Phineas Gage
prefrontal damage didn’t alwyas result in same control problems so must be different control functions and don’t co-occur:
- utilisation behaviour - unable to suppress habitual actions to familiar objects
- perseveration - e.g Wisconsin card- difficulty in shifting task-set
- difficulty in evaluative decision making - linking emotions to choice
- disordered planning - e.g mutiple errands task showing disorganised performance
what does different control processing problems after damage to prefrontal cortex dispute?
idea of single executive homunculus
instead have distributed network of control mechanisms
how to capture control in the lab?
1) supress a task-set
2) reset control parameters
3) inhibit actions
4) manage multiple info flows
isolate effects of these demands on performance from effects of task-specific processes
e.g dual-task performance
describe results in Stroop’s colour naming test related to task-set?
in measuring control response and conflict
have task-set for colour-naming and for reading
try to selectively attend to colour and apply naming task-set but can’t suppress the reading task-set (more habitual)
so longer RT when seeing word but saying colour due to response conflict
describe the Flanker effect?
in measuring control response and conflict
response conflict triggered by application of instructed task set to irrelevant objects
surrounding letters either neutral, incongruent or congruent (the same)
describe study investigating the task switching paradigm?
describe task-switch cost?
when is it reduced?
what were the results?
predictable switching paradigm e.g after every 4 trials
task-switch cost: extra processing necessary (shown by increased activation in brain) to switch task
- reduced when longer preparation time due to time for mental reconfiguration but never disappears (residual cost)
found faster when responses congruent (using same modalities) and when incongruent then get conflict from other task (other task-set still active) so slower
what is meant by task-set inertia?
what does it explain?
task-set from other task still lingers around
so always residual cost in task switch performance and switch cost never disappears
using neuroimaging to study task-set preparation and response conflict?
what has it shown about the left dorso-lateral prefrontal cortex and anterior cingulate?
in lateral dorsal lateral prefrontal cortex
when preparing for harder task needing more top-down control (saying colour not reading word), increased activation in this part of brain
so involved in activating a task-set
anterior circulate important in error-monitoring and conflict detection (activation when incongruent stimuli)
describe results of imaging ‘task-set inertia’ with fMRI study?
what did it find?
what does it explain in terms of residual switch cost?
found that switch trial related activaton of face area predicted switching to word task
more activation in face area the harder it was to switch to word task
more activation in word specific area, harder to switch to word task
residual switch cost to do with carry over of activation from previous task and inability to suppress completely
which processes are prolonged on task-switch trials?
what attributed to?
early processes prolonged on switch trials
attributed to ‘attentional inertia’ not able to pull attention completely away from other task
what is the stop-signal task?
what did they find?
what did fMRI find?
who is stopping especially impaired in?
tone signals to stop responding
later stop signal comes then more difficult to stop as process already quite far so harder to inhibit response
fMRI shown brain regions associated with stopping (TMS impairs stopping not going)
stopping impaired in those with ADHD, OCD and tourette’s
when may the need for executive control be the highest?
when performing a nonhabitual/effortful task
when performing competing tasks of similar strength
