Casey et el

Describe the background research

- Mischel et al tested 4 yr olds put marshmallow infant of them: told either eat it or wait until researcher returned and get another

-tested again at 20 and again at 30

-using self reports researchers found individuals who were unable to resist temptation at 4 were still having problems controlling behaviour in 20s and 30s

Difference between casey and mischel et al

-casey uses brain scanners

-casey focuses on participants at age 40

Casey aim?

-to investigate whether resisting temptation (delay of gratification) would have a correlation with what parts of the brain were active (neural patterns)

Hypothesis?

p's with consistently low levels of self control from young childhood to early adulthood would have diminished activity in the pre-fontal cortex and amplified activity in the ventral striatum

research method?

Quasi experiment as the IV : whether P was high/low delayer from childhood study was naturally occurring so couldn't be manipulated or controlled by researcher

DV?

Performance on impulse control tasks in terms of reaction times and accuracy in exp 1. same measured in exp 2 but with added imaging results from the fMRI scans

Why is it considered a longitudinal study

-Studied from 4 till age 40's , in between some p's did self control scales in 20s and 30s.

Describe the sample of the original marshmallow study

-From stanford university bing nursery school:562 4 yr olds

How many experiments were there

2

describe exp 1 sample

-59 p's all from original marshmallow study now aged in their forties

What was the tempting stimuli used by Casey

-social temptation: Smiling, fearful, neutral photos of males and females.

what was the task called that p's took part in

impulsive control task: go/no go task

Participants were tested _____ and completed the test on a _____ that was _________

participants were tested individually and completed the test on a laptop computer that was sent to their home

What were p's told before the task

-to complete the task as quickly and accurately as possible

How long did each face appear on screen?

500 ms : half a second

Each time p's saw a new face is called a ____. each p did ___ sets of ____ trials. 2 were ___ and the other 2 were ___

Each time p's saw a new face is called a trial. each p did 4 sets of 160 trials. 2 were cool versions the other 2 were hot versions.

Were the faces neutral/smiling or fearful?

-Go face=male

-120 were male: go faces, 40 were female= no go faces

-All of the faces were neutral (not smiling/fearful)

Describe set 2

Identical to set 1 but the go face was changed from male to female.

What were p's tested on?

how accurate they would be at pushing the button every time they saw the go face

Results exp 1

-low delayers accuracy was 11.2% compared to high delayers 15.7%

Exp 2 sample?

27 out of the 59 from exp 1 continued to exp 2

Differences to experiment 1?

-it was in the lab not their home

-Shorter sets; 48 trials;35 go 13 no go

Quantitative result from exp 2?

In the hot task where the happy face was no go low delayers made 14.9% mistakes compared to high delayers 10.9%

Major finding over all

It was only the emotional (hot cues) that produced differences between low and high delayers

Conclusions?

-our ability to resist temptation stays stable in a 40 year life span; those who have difficulty delaying gratification with marshmallows as children will also have difficulty suppressing responses as adults

Evaluate the research method

+= Quasi experiment so the IV was naturally occurring (high or low delayer) no manipulation by researcher so results on delayed gratification are more ecologically valid

-= Quasi experiment so lack of control from researcher, less control of participant variables so cannot be sure it is really being a high/low delayer that affects accuracy on impulse control tasks

Evaluate the data

+ = quantitative data so results on delaying gratification can be compared and analysed between low and high delayers

-= quantitative data so lacks insight into why participants delay gratification and others don't=no info why brains and behaviour are varied

ethical strength

+ = gathered informed consent in both conditions and no psychological or physical harm to participants, they are treated in the humane way.

Reliability strength

+ = Standardised procedure,all p's instructed to respond as quickly and accurate as possible and every face appeared for 500 ms (half of a second.)

Therefore results on delayed gratification are reliable

Evaluate the sample

+ = very large sample gathered from 562 pupils from stanford university's bing nursery school so results on delayed gratification can be generalised to the whole population

-= ethno centric as all from stanford university's bing nursery school so results on delayed gratification cant be generalised to people from other areas

Validity weakness

-lack of ecological validity as the fMRI scans and the impulsive control tasks are not close to anything that p's would do in real life

ethics weakness

-socially sensitive; suggests ability to delay gratification is pre-determined and cannot be improved= may lead to labelling, and employers only offering jobs to high delayers.

Casey link to area

-Links to the biological area assuming all that is psychological is first physiological: The mind resides in the brain so all behaviour has a biological cause

-This is because Casey links participants ability to delay gratification (with holding from pressing a button) to their biological brain structure

-Casey found the ventral striatum in the limbic system was significantly more active for the low delayers in trials were happy face was 'no go'= suggests ventral striatum is involved in giving in to get rewards

-Therefore delaying gratification has a biological cause; it depends on which parts of the brain are active.

Casey link to theme

-theme =regions of the brain

-casey found evidence for 'hot' and 'cool ' systems in the brain: the ventral striatum and the inferior frontal gyrus

-Casey found the ventral striatum was significantly more active for low delayers in trials were the happy face was no go, suggesting the ventral striatum is involved in giving in to temptation

-Casey found that the right inferior gyrus was more active in the 'no go' trials when participants had to withhold a response=suggests pre frontal cortex helps us to delay gratification

Does casey change our understanding of the theme?

-Yes; it adds to our understanding of the brain

-sperry identified the role of the corpus callosum and hemispheres in general

-Sperry studied the effect of having a split brain and found that information presented to the right visual field could be described in speech and writing as it was processed by the left hemisphere, but when info was presented to the left visual field the P insisted he didnt see anything and could only point with his left hand to a matching picture

-casey identified specific regions that play a role in self control and found the ventral striatum was significantly more active for low delayers in trials were the happy face was no go suggesting that the ventral striatum is involved in giving in to temptation

Casey links to debates

-Psychology is a science; the study is falsifiable, replicable and was well controlled

-Nature: the ability of p's to delay gratification as children affected them the same way as adults = cant be changed

what is delay of gratification

when you can successfully delay an object or activity you would enjoy (gratification) i.e when you can resist temptation

ways to delay gratification?

-use a cognitive process known as cooling: making a hot stimuli cool e.g rather than thinking of marshmallows taste think about shape/what it looks like

What are cool systems

parts of the brain that are involved with cognitive control (ability to control thoughts) : focus on resisting temptation: pre frontal cortex and inferior frontal gyrus

What are hot systems?

parts of the brain that are more emotional and lack control. they are more active when the brain wants a tempting stimuli: the limbic system, in particular the ventral striatum.

-155 were studied in their 20s

-135 were studied in their 30s

-p's split into 2 groups based on results of experiments they did at age 4/20/30: low delayers (gave into temptation) and high delayers (could delay gratification)

-Smiling photos meant to be the tempting stimuli.

-they would be shown a series of male and female faces

-to push button every time certain face appeared e.g male face (go) and not to push button if female face appeared (no go face)

In set 1 what was the go face?

How many faces they saw were go faces compared to no go faces?

In set 3 what was the go face?

How many faces were go compared to no go?

Go face= smiling face

120 were smiling, 40 shown other expressions; fearful/neutral

Describe set 4

Identical to set 3 except the go face= fearful face

-low delayers performed worse on the hot trails pushing the button for 'no go' faces, especially when happy face was no go.

-this time p's were being scanned with an fMRI scanner as they did the task; so researcher could see which part of brain was active

give 2 qualitative results from exp 2

-fMRI analysis shows the right inferior gyrus was more active in the 'no go' trials when participants had to withhold a response=suggests pre frontal cortex helps us avoid giving in to temptation

-the ventral striatum in the limbic system was significantly more active for the low delayers in the trials were the happy face was 'no go'= suggests limbic system is involved in giving in to get rewards

-the fMRI results show us there is a physiological basis for resisting temptation,may explain why some find it easier to delay gratification