cognition- executive function Flashcards
central executive function
definition
-mental processes for regulating and controlling other cognitive processes, in particular in relation to complex actions
why are they called ‘executive’
-they manage task processing
-they are not actually involved in performing the task
the three major executive functions
inhibition
shifting
updating
executive function : inhibition
-inhibition : control ones attention, behaviour, thoughts, and / or emotions to override a string internal predisposition or external lure
-can include inhibition of attention : resisting distractor interferences
-includes inhibition of action : inhibiting a prepotent response
shifting
-to switch flexibly between tasks or mental sets
-called shifting ability
updating
-to monitor and engage in rapid addition or deletion of working memory contents
-eg removing stuff that’s not relevant anymore
tasks used to measure executive functions
-stroop task (stroop,1935)
ef inhibition of attention task
-to measure inhibition of attention people often use the stroop task
-name colours in which words are printed
-in congruent condition - the word green shows in green ink (response is faster as they just say green
-incongruent - the word green in red ink (response is red but slower response)
ef task inhibition of action
stop signal task (logan and cowan,1984)
-indicate the direction of the arrow, but stop responding when hearing a beep sound (the stop signal)
-by varying the time you play the stop sound you can measure the response and how could you are at inhibition of action
ef task shifting
number-letter task (rogers and monsell, 1995)
-part of the experiment you will only see a letter and a digit on the upper side of the screen, and you need to judge whether they are even or odd numbers
-in another section of the exp you will see the digit and letter combination on the lower side of the screen and you have to make a judgement on whether the letters are vowels or consonants
-but in the final part, you will see the combination of the letters and numbers one by one in clockwise order, so first make judgement on numbers then on the letters (and so the task is shifting)
-by comparing the reaction time it takes you to switch from this shifting task compared to the previous exp tasks , we can measure how long it takes for you to shift from one task to another
- ef updating
tone monitoring task (Larson, Merritt and Williams 1988)
-3 types of tones (high,low,medium) played in a random sequence
-respond when the 4th tone of each particular pitch was presented (eg after hearing the 4th low tone, the 4th medium tone, 4th high tone)
relationship between different executive functions
according to unity/diversity framework (Miyake and Friedman 2012) what do they say about it?
- each executive function has a component that is common to all executive functions
-and also has a component unique to that specific to that particular executive function
Miyake and Friedman 2012
-experiment on relationship among EF
-unity/diversity framework
-findings between the efs
-conducted experiment on the abilities of many participants
-did a sort of structure equation analysis so that they can understand a correlation
-for updating and shifting ability they do have a common executive function, and plus a specific updating component or specific shifting component
-for inhibition ability, almost perfectly overlaps with the common executive function
-according to their findings they believe the common executive function is the ability to maintain task goals and goal related information and use this information to effectively bias lower level processing
what is common for all executive functions (Miyake and Friedman 2012 ) findings
-according to their findings they believe the common executive function is the ability to maintain task goals and goal related information and use this information to effectively bias lower level processing
relationship among efs
-evidence/testing the unity/diversity framework (Hedden and Gabrieli 2010)
-used a brain imaging task
-in this task both inhibition and shifting function was measured
-tried to identify brain network that’s associated with inhibition task and shifting task (as its found previously these two functions overlap, so the brain network used for these 2 tasks should also overlap)
-global local task
-identify either the global (large letter) or the local (small letter) level on each trial, as cued by the colour
-congruent condition - global and local letter is the same
-incongruent condition - local and global letters conflict each other (H is made up of smaller local sses)
-congruent condition would require little inhibition function but the incongruent condition you would require more
-also measuring the shifting condition, by having two colours so if its blue eg you only judge the local letter and if its green you judge the global letter
evidence/testing the unity/diversity framework (Hedden and Gabrieli 2010)
results
-there was considerable overlap in the brain areas associated with inhibition and shifting
-there was also evidence of diversity, especially with respect to the inhibition
-does not support the unity framework as that suggests that inhibition function has nothing unique to itself (no diversity) but in the brain scans you can see parts of the brain solely associated with the inhibition function
dysexecutive syndrome
brain damaged individuals whose EF is impaired
Godefroy et al,2010 - what did he say about dysexecutive function
-according to him, dysexecutive syndrome includes impaired response inhibition, rule deduction and generation, maintenance and shifting of sets, and information generation
Iowa gambling task in brain damaged patients (Glascher et al.2012)
-participants were shown four decks of cards
-each deck holds cards that will either reward or penalise them, using game money (eg rewarding card you get more game money)
-goal of the game is to win as much money as possible.
-‘good decks’ reward the player more often than bad decks
Iowa gambling task in brain damaged patients (Glascher et al.2012)
results
-ordinary healthy participants would be able to find out that among the four decks some contain more rewarding cards than others
-eg they learn this rule there are some that are good and some bad
-those with dysexecutive syndrome were deficit in this task,
-by looking into the brain region damaged of they found two networks that associate with the damage of this task
two separate brain networks associated with the damage of dysexecutive syndrome task
-a cognitive control network associated with response inhibition ,conflict monitoring and switching
(so the executive function)
-a value based decision making network associated with emotion and value judgements. (this isnt executive function, this is a different network, so if you had brain damage in the value based decision making network you would also be likely to fail the task)
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evidence supporting training improves the executive function
kimberley and william 2004
-study
-askeed children from kindergarten through to grade 5 to either exercise martial arts or just traditional pe lessons
-four 45 min training sessions each week, this lasted 4 months
-after this children were tested on their self regulation ability in 3 domains
-physical : the level of physical control and skilfulness.
-cognitive : focus attention and efforts on the task at hand
-affective: self confidence , emotional control , persistence and will
evidence supporting training improves the executive function
kimberley and william 2004
results
-martial arts training group led to greater gains in all three areas of self regulation, with the greatest gains in cognitive and affective self regulation
-both boys and girls benefited from martial art training than ordinary pe activities , with boys gained more than girls
-children at older ages benefited more than younger age children did
-concluded that using techniques such as mediation, self monitoring or martial art instructors teach students to be more self aware and to own the responsibility for correcting their thoughts and behaviours , therefore this kind of training can improve their self regulation ability
bergman nutley et al 2011: tested transfer of Ef training in 4 year old (whether it can be transferred in 4 year olds)
-the software guides child through several rotating exercises each day (mental rotation task)
-the exercise becomes more difficult in small steps as the child’s ability to handle them improves
-10-15 minutes every week day for 5 weeks
evidence supporting training improves the executive function
kimberley and william 2004
results
-training on spatial working memory can transfer to other measures of spatial working memory but not visual working memory
karbach and kray 2009
switching task
and results
-they trained a 4 year old on a switching task.
They found that the beneficial effect transferred not only to an untrained task switching task, but also to inhibition (stroop interference) , verbal and non verbal working memory, and reasoning
-this study found more generalisable results
conclusion of ef training
-to what extent does ef training work
-if ef training tasks are more demanding and more difficult, they are more likely to generalise to other EF tasks. It is often only in pushing the limits of children’s EF skills that beneficial effects emerge.
kovacs and mehler 2009, wass et al 2011)
-exposure to bilingual input can ______ the development of Executive Functions in infants.
accelerate/benefit
kovacs and mehler (2009) study on inhibition of habitual responses in 7 month old infant
-what were the two grouos
-what was the task/how was it carried out
-they got bilingual infants ,they had parents with different mother tongues , and both parents addressed them consistently in their own native language, and the infant also consistently had exposure to both languages (bilingual infant group)
-monolingual group (only exposed to one type of language
-monolingual and bilingual infants were matched for age , gender, and their parents’ socioeconomic status
the task:
presented infants a fixation cross in the beginning and then present them different cues in each exp
1st exp: presented random words eg lemovo
2nd exp : they presented with verbal cues that have repeated structures eg lemomo
3rd exp: visual cues
-certain cues led to a toy to appear on 1 side of the screen
-between the cue and presentation of toy, there is an anticipation period between and they wanted to compare children’s ability how quickly the children could anticipate the correct location of the toy (in the pre switch trails participants learned association between cue and location of toy (either left or right hand side of the screen) so eg visual cue red circle and left hand side toy.
-different cues led to a toy to appear on the other side in the post switch trials
-during the post switch , infants had to learn to redirect their gaze from the previously valid side towards the opposite side of the screen.
-infants with stronger inhibition should redirect their gaze earlier
kovacs and mehler (2009) study on inhibition of habitual responses in 7 month old infant
results and conclusion
-in the pre switch trials where they just learn the association between particular cue and presentation side of the toy, both monolingual and bilingual groups show similar learning rate (fast learning) and no group difference
-but after the switch (and the rule became the opposite) for the monolingual infant, they hardly learnt anything. but for bilingual infants improved significantly-they learned the opposite rule faster (only bilinguals displayed an increase in correct anticipatory looks
-concluded that multilingual environment improves inhibition even in preverbal infants
Bialystok et al 2004
-bilinguals preserve the executive functions longer during aging exp
procedure
-bialystok examined whether bilingualism attenuates the negative effects of aging on cognitive control in older adults
-they compared the performance of monolingual and bilingual middle aged and older adults on the simon task
-simon task: judge the colour of object on screen , left key for blue and right key for green
-in compatible group blue colour appears on same side as the key ,whereas incompatible (incogurent) condition, the colour appears on the opposite side (will take more inhibition function in the incompatible condition
-bilinguals : speakers of English and Tamil living in India , of English and Cantonese living in Hong Kong and English and French living in Canada
-monolinguals : speakers of English living in Canada.
Bialystok et al 2004
-bilinguals preserve the executive functions longer during aging exp
results
-age related increase in inhibition costs was greater for monolingual than bilinguals
-when it got the age bracket of 50-59, after that the inhibition ability of monolinguals significantly decreased compared to bilinguals
findings of bilingualism and EF called into question
Gathercole et al 2014
gathercole explored the extent to which a bilingual advantage in EFs can be observed in an established population of fully fluent bilinguals from childhood through adulthood
-bilinguals : welsh-english simultaneous and early sequential bilinguals from north Wales
