Executive Processes And Dusexecutive Disorders Flashcards
Areas of brain associated with intact and impaired executive processes
Largely associated with pre frontal lobes
Last area to fully develop (teens/early adulthood) & first to become less efficient with age
Panning action sequence
Create plan
Execute
Alter if circumstances require change
Evaluate outcome
Tests of executive process : Tower of London/Hanoi
Must pre plan to complete
3 moves in order to complete
Patients with frontal love damage find difficult as have to be counterintuitive
BUT can do tasks with same components that do not require planning - block design
Verbal fluency task
Strategy generation task
Given 60 seconds to generate as many words beginning with a letter or within a category
Frontal lobe damage = fewer responses - tend to repeat derivatives of the same word
Wisonsin word sort task
Looks at ability to follow rules and use feedback to amend actions
Work out sorting rule of cards - sorting rule changes after 6 successful trials so must adapt to new rule
Frontal lobe damage perseverate - continue to follow old rule despite negative feedback and being explicitly told the rule has changed
Luria 1966 frontal lobe use
Frontal lobes contain system for programming, regulation and verification of activity
Symptoms of frontal lobe damage
Distractability - hard to focus
Inability to initiate tasks - plan but don’t do
Carry out irrelevant/inappropriate actions
Norman and shallice model of control and coordination of actions
Two modes of action control
Routine or novel
Routine: Cues or triggers activate the action schema and allows the routine to be performed - under the control of contention scheduling
Define contention scheduling - Norman and shallice
Internal or external cues trigger units to activate schema
Schema activation exceeds threshold level and schema is selected
- action initiated
- competing schemas inhibited
(Common parts of schema shares so must inhibit to prevent absent minded errors)
Contention scheduling and intended actions
Novel and infrequent actions more subject to error
CS system = driving familiar route to work
BUT when must deviate from the route, the supervisory system must activate
SS biases way CS works by applying extra exit cation or inhibition to select required action - override CS we point in toting to activate/inhibit and alter the normal process
Frontal live damage and the SS and CS
Fail to alter sequence in WCST - supervisory system in frontal lobe is damaged do does not override CS
CS in posterior brain region and intact &I so not moderated by SS
Define perseveration
Strong cue schema response
Follow most well learned or recently executed response to a cue and fail to alter
Define inertia
Inappropriate action when cue schema link is week
Can’t select schema or alternate between actions
simple executive processes
Task switching - ability to shift back and forth between tasks or between mental sets
Inhibition - ability to suppress and dominant or automatic response
Updating - ability to actively monitor and update info in working memory (evaluate)
Ie required in planning and completing future tasks (PM) - inhibit current activity, switch to PM, update memory and encode if successful
Miyake et al 2000 tasks for simple executive processes
tasks for switching:
‘Plus minus task’
- add numbers in list
- subtract numbers in list
- add and subtract numbers in list (switch)
Tasks for inhibition:
‘Stroop task’
Inhibit read of word and read colour instead
Test of updating:
‘Letter memory task’
Present letter one at a time for 2 secs
Task to remember last 4 letters presented (constantly update)
