Casey Flashcards
What parts of the brain are associated with ability to delay gratification
Inferior frontal lobe = helps inhibit or delay responses eg.avoid temptation
Ventral striatum = high activity means you want immediate gratification + find it hard to resist temptation (reward hub)
Previous research to casey
showed that preschoolers who directed attention to rewarding things (cookies) had more difficulty resistng inappropiate actions in adulthood
Casey Aim
to test whether delay of gratification in childhood predicts impulse self-control in adulthood
Sample of Casey
drawn from cohort of 562 pupils aged 4 who had completed marshmallow test in 1960s
those who also did self-control questionnaire in 20s/30s
117 were contacted as they were above or below average in these tests
59 participants took part in experiment 1
27 participants took place in experiment 2
males + females
one male participant results removed due to poor performance in experiment 2
Research Method of Casey
Quasi - experiment
= didn’t manipulate who was ‘low delayer’ or ‘high delayer’
Longitudinal study
= age 4 until their 30s
IV and DVs of Casey
IV - whether participants were high or low delayers based on marshmallow test when they were 4 + scored high/low on self-control questionaire
DV = accuracy on go/no-go task and fMRI activity readings
Why didn’t Casey use marshmallows to test delay of gratification
believed that what we find tempting changes as we age
eg social acceptance is more gratifying for adults than marshmallows
Experiment 1 of Casey
Participants carried out go/no-go task at home with laptops.
Pictures of numerous faces were flashed on screen for 500miliseconds followed by a 1 second interval between faces.
Participants were given instructions on when + when not to press a button (go/no-go task)
Hot task = participants shown fearful + happy faces
Cold Task = participants shown male + female faces
eg. asked to press button when see fearful face
DV - how many mistakes they made + reaction times
Researchers thought they would make more mistake on hot task as it would be tempting to press when they saw happy face as its a tempting social cue
Experiment 2 of Casey
Participants carried out same go/no go task in experiment 1 but in an fMRI scanner
errors and reaction times were compared between low delayers and high delayers
Describe what a Go/No-Go task was in Caseys study
computerised test
used to assess inhibitory control eg. can were control our responses
each trial consists of one stimulus eg. fearful/happy (hot task) or male/female (cold task) indicating to press button (GO) or not (NO-GO)
Results of Experiment 1 in Casey’s study
Low + high delayers had similar accuracy in ‘cool’ task
low delayers performed worse on hot task than high delayers
eg. found harder to suppress their responses to happy faces compared to high delayers
Results of Experiment 2 in Caseys study
Low delayers made more mistakes than high delayers in hot task as in experiment 1
fMRI found low delayers had less activity in inferior frontal gyrus and more activity in ventral striatum during go/no-go tasks compared to high delayers
Conclusions of Casey
The ventral striatum is a ‘reward hub’ of the brain is more active in low delayers
The inferior frontal gyrus is less active in low delayers
Generalisability of Casey
paricipants all came from Stanford uni nursery in USA
particpants from similar background (academic’s children) and from one culture
longitudinal study as attrition of sample, sample bias as certain people stay
Is Casey ethnocentric
focused on American culture
people from other cultures might be taught to control impulses differently
Reliability of Casey
RELIABLE
= exp 2 under lab conditions using fMRI scanner so extraneous variables controlled.
if experiment repeated with same equipment, would get similar results
= exp 1 had standardised programme + recorded response accuratly
UNRELIBLE
= participants carried out task at home
= distractions in environment could have affected participants response > harder to replicate
Applications of Casey
shows differences in our brain determine how could we are at resisting temptation
suggests that we should train the brains of low delayers to improve achievement, physical health and relationships
Validity of casey
LACKS ECOLOGICAL VALIDITY
go/no go task is artificial as its not how we would usually respond to facial expressions
fMRI scanner while doing go/no go task isn’t an everyday task + could’ve affected response
Ethics in Casey
no ethical issues
- no deception
-right to withdraw
- no harm
Quantitative data in Casey
experiment 1 - counted no. of errors they made in go/no-go task
allowed casey to compare the number of errors made by high and low delayers
How does Casey relate to key theme ‘regions of the brain’
revealed that there is two regions of the brain that have an impact on our ability to delay gratification
high activity in inferior frontal gyrus + low activity in ventral striatum can help us delay gratification
How does Casey change our understanding of key theme of ‘regions of the brain’ compared to Sperry
Sperry only looked at corpus callosum and communication between L+RH
wheras Casey looked at activity in inferior frontal gyrus and ventral striatum
How does Casey relate to biological area
= biological area looks at how genes, hormones, brain structure affect our behaviour
= looked at how activity in particular brain regions affect our behaviour
= found high activity in inferior frontal gyrus + low activity in ventral striatum are linked to ability to delay gratification
Hoe does Casey et al change our understanding of individual, social and cultural diversity
INDIVIDUAL - Casey found individual differences in peoples ability to delay gratification from early childhood. individual differences between brain structure can affect ability to delay gratification
Sperry looked at individual diversity in split-brain patients who had different streams of consciousness in RH+LH
SOCIAL - Casey used participants who attended stanford uni nursey + did marshmellow test so middle-class - few females
Sperry more socially diverse (M+F)
CULTURAL - both studies carried out in USA
