Casey - Biological area Flashcards
What did earlier research from Eigsti (2006) show?
Showed performance on a delay-of-grat task in childhood
predicted the efficiency with which the same individuals performed a cognitive control task (go/no-go task) as adolescents and young adults
What is the marshmallow experiment?
- It is an experimental design that measures a child’s ability to delay gratification
- The child is given the option of waiting a bit for a new marshmallow, or if they didn’t wait, they would get a less desirable treat - one marshmallow
- The minutes or seconds a child waits measures their ability to delay gratification
Who was called as a High delayer in the marshmallow task?
Could wait for another marshmallow and delay gratification
Who was classed as a low delayer in the marshmallow task?
Those who could not wait for another marshmallow and they ate it before the 15 minutes was up
What was the alluring stimulus in the task?
Marshmallow
What is the effect of being able to delay gratification/resist temptation?
The ability to resist temptation in favour of long-term goals is an essential part of individual, societal and economic success
What can alluring situations result in?
Alluring situations can diminish control
What does delay of gratification depend on?
Cognitive control
What correlation has been found?
A correlation has been found between an avoidance of risky behaviour and greater excitation in the right inferior frontal gyrus
What was found about the ventral striatum?
- It has been found that functionally, the ventral striatium helps and balances motivation with both higher-level and lower-level functions, such as inhibiting one’s behaviour in a complex social interaction.
- This region has been found to be the region in the basal ganglia neural circuit that’s most closely associated with reward.
What was the aim of Casey et al’s study?
- The aim was to build on earlier research to assess whether delay of gratification in childhood predicts impulse control abilities
- and sensitivity to alluring or social cues (happy faces) at the behavioural and neural level when participants were in their 40s (adults)
Experimental method?
Quasi experiment
2 Experimental design?
- Independent measures design - High v low delayers
- Repeated measures design - age
Why could it be considered a repeated measures design?
Some participants completed self-control scales when in their 20s and 30s and that those taking part in experiment one did both the ‘hot’ and ‘cool’ go/no-go task
What was the IV?
Whether the participant was a high delayer or low delayer
What was the DV?
- Performance on the impulse control task (in terms of reaction times and accuracy) in exp 1
- And the performance on the impulse control task (reaction times and accuracy) and imaging results using the fMRI scanner in exp 2
How many participants were from the original delay of gratification task
562
Where was the study conducted?
Stanford’s Bing Nursery School
How old were the children in the original study?
4 years old
What year was the original study in?
Late 1960s, early 1970s
How many people did self-control scales when in their 20s and 30s?
- 20yrs = 155
- 30yrs = 135
How many were contacted to take part in Casey’s study?
117
What specific people were contacted for the study?
Those, 117, who were above average or below average in their original delay of gratification performance as well as in the self-report measures of self-control were contacted in relation to taking part in this study.
How many agreed to take part in the longitudinal behavioural study (exp 1)
59 of the 117
What was the female to male comparison?
- 23 males
- 36 females
How were participants classified?
- P’s classified as low or high delayers from their results of:
- a) their delay of gratification performance
- b) self-control measures
How many high delayers were in experiment one?
- 32 high delayers
- 12 males, 20 females
How many low delayers were in experiment one?
- 27 low delayers
- 11 male, 16 females
How many agreed to be apart of a functional neuroimaging study in experiment two?
- 27 of the 59
- (13 males, 14 females)
How many HD + LD were there in exp 2?
- 15 high delayers
- 11 low delayers
Why was one participant excluded?
One 41 yr old man was excluded from all analysis because of poor performance
In the end, how many participants were in experiment two?
26
What is subject attrition in a longitudinal study?
- When participants drop out of the study for any reason and do not return to complete the study
- It can threaten the study’s validity
What did experiment one test?
Tested whether individuals who were less able to delay gratification as a child and young adult (LD) would, as adults in their 40s show less impulse control in suppression of a response to ‘hot’ relative ‘cool cues’
Did participants give consent?
59 participants, already LD or HD, consented to take part in a behavioural version of a “hot” and “cool” impulse control task
How many times did the P’s complete versions of the go/no-go task
Participants completed two versions of the go/no-go task
What did the ‘cool’ version consist of?
- Consisted of male and female stimuli which were presented
one sex as a ‘go’ (target) stimulus to which participants were instructed to press a button
- Other sex as a ‘no-go’ (non-target) stimulus to which P’s were instructed to withhold a button press
What happened before the onset of each run?
A screen appeared showing which stimulus category served as the target
What were participants instructed to do?
instructed to respond quickly and as accurately as possible
How long did the face appear for?
500ms
How long was the interval that followed the face appearance?
1-s interstimulus interval
How was the ‘hot’ version of the go/no-go task similar or different to the ‘cool’ version?
- Similar - identical
- Different - fearful and happy facial expressions served as stimuli
How were the laptops standardised? where were they sent?
- Tasks were presented using programmed laptop computers
- It was sent to P’s homes
What was the fMRI scanner used for?
Used to examine neural correlates of delay of gratification
What was expected of LD?
Expected that LD would show diminished activity in the right inferior frontal gyrus and amplififed activity in the ventral striatum compared to HD
How many participants agreed to complete the imaging study?
27 P’s from Exp 1 consented
What did P’s complete?
‘Hot’ version of the go/no-go task like that used in exp 1
What was a difference in the hot go-no/go task to exp 1?
- Timing
- Number of trials
- Apparatus
How long was each face presented for? what was it followed by?
- 500 ms
- Followed by a jittered interial interval ranging from 2 to 14.5s in duration
How many trials were presented in pseudorandomised order?
48 trials
How was the task made viewable to Ps?
- Viewable by a rear projection screen
- And a Neuroscreen five-button response pad recorded button responses and reaction times
When responding to the ‘go’ trials, how did Ps do?
- High level of accuracy for correctly responding to go trials
- cool (99.8 % correct)
- hot (99.5% correct)
How did LDs do on the no-go?
- Accuracy for no-go was more variable
- LD commiting more false alarms than HD
Results for LD and HD
- Low and high delayers performed comparably on the “cool” task but the low delayers trended toward performing more poorly on the “hot” task
- than the high delayers; only the low delay group showed a significant decrement in performance for the “hot” trials relative to the “cool” trials.
What did it show about LD and HD as adults and children
go/no-go task produced differences between the delay groups only in the presence of emotional “hot” cues i.e., individuals, who as a group, had more difficulty delaying gratification at four years of age (low delayers) showed more difficulty as adults in suppressing responses to happy faces than the high delayers.
Result for accuracy (1)
Overall accuracy rates for the “hot” go/no-go task were uniformly high for “go” trials (mean 98.2% correct
hits) with more variable performance to “no-go” trials (12.4% false alarm rate).
What differences were observed?
- Differences between the two delay groups in “no-go” accuracy were consistent with the observed differences in the “hot” task performance
- LD commited more false alarms than HD
What did the trials show about the brain?
The “no-go” vs. “go” trials found candidate regions of the brain differentially engaged as a function of
cognitive control tasks.
What was the right inferior frontal gyrus associated with?
RIFG was associated with accurately withholding a response
Compared with HD, what did LD show?
Diminished recruitment of the right inferior frontal gyrus for correct ‘No-go’ relative to ‘go’ trials
What did the ventral striatum reveal about LD?
- Reward-related region of the brain showed a three-way interaction of group x trial x emotion
- Elevated activity to happy ‘no-go’ trials for LD
- Exaggerated recruitment in LD
What plays a significant role to an individual’s ability to suppress actions towards alluring cues.
Sensitivity to environmental hot cues plays a significant role in an individual’s ability to suppress
actions toward alluring cues.
Give a conclusion about resisting temptation by context
The ability to resist temptation varies by context, the more tempting the choice for the individual, the more predictive are the individual differences in peoples’ ability to regulate their behaviour
Give a conclusion about how being a LD or HD didn’t really change over time
Individuals, who, at the age of 4, had difficulty delaying gratification and who continue to show
reduced self-control abilities, have more difficulty as adults in suppressing responses to positive social cues than those who don’t
