BIOLOGICAL: Casey et Al. (2011)

Question 1

What is the aim of the study?

Answer 1

To test whether delay of gratification in childhood PREDICTS impulse self control abilities in adulthood.

Question 2

What is “delay of gratification”?

Answer 2

Putting off something that is attractive and tempting NOW for something more better LATER.

Question 3

Why did Casey carry out this study?

Answer 3

-Psychologists believe we use ‘Cognitive control’ to create strategies to delay gratification.
-Cognitive control works by suppressing inappropriate thoughts/actions. EG. ‘cooling’ -> directing away attention from the hot cues (attracting) by focusing on cool cues (the less attractive).
-Past study suggest that cool and hot patterns of thoughts involve their OWN NEUROCOGNITIVE SYSTEM:
COOL cues are based on cognitive control and HOT cues are related to desires and emotions.

SO casey wants to investigate whether the region of INFERIOR FRONTAL GYRUS and VENTRAL STRIATUM.

Question 4

What is the design of the study?

Answer 4

a LONGITUDINAL STUDY following some participants from 4yrs to 40yrs.

Made up of 2 QUASI EXPERIMENTS because the IV of being a high delayer and low delayer is not manipulated by the researcher.

BUT ALSO, because the participants in exp 1 did BOTH hot and cool versions of the no/go task, in some way it has a REPEATED MEASURES design too.

Question 5

What was the DEPENDENT variable?

Answer 5

Performance on the impulse control tasks and accuracy and reaction times.
Brain activity through the fMRI scans in Exp.2

Question 6

How many children aged 4 completed the delay of gratification task?

Answer 6

562 pupils at STANDFORD BING’S NURSERY (aged 4)

Question 7

How many participants completed the self control scale at the age of 20 and then 30?

Answer 7

20years - 155

30 years - 135

Question 8

Who participated in experiment 1?

Answer 8

117 were contacted (the people that had below or higher average scores) but only 59 consented to take part.

Question 9

Of the 59 participants how many low and high delayers were there?

Answer 9

32 High; 27 Low

Question 10

How many continued to take part in experiment 2?

Answer 10

27 but one participant’s data was excluded (15 high delayers; 11 low delayers)

Question 11

What happened in experiment 1?

Answer 11

-Participants received a pre-programmed laptop and were to complete 2 versions of the go/nogo task.
Version1 = “cool” a total of 160 trials (120 go and 40 nogo)
Verson2 = “hot”
Before each run there was a screen with instructions stating which was the go and what was the no go and instructing to respond as quickly and accurately as possible.

Question 12

What was the stimulus (the go) for the hot task and for the cool task?

Answer 12

cool = gender
hot = happy faces/ fearful faces

Task was a 2 (stimulus) X 2(go/nogo) factorial design
(so the go was changed)

Question 13

How long was each face shown for?

Answer 13

500ms followed by a 1s interval between faces

Question 14

How were the delayers classified as LOW/HIGH?

Answer 14

through the self control scale they completed at age 20 and 30.

Question 15

What happened in experiment 2?

Answer 15

fMRI was used to examine neural correlation of delay of gratification:

• Participants completed the HOT version task whilst being scanned in fMRI scanner.
• The task was exactly the same except there were 48 trials (35 go and 13nogo) and intervals ranged from 2seconds-14.5 seconds between faces.
• At the rear end the task was visible and there was a electronic response pad that was used to record the button responses to the stimuli and the reaction times.

Question 16

How many fMRI imaging data did researchers collect from experiment 2?

Answer 16

26 no go

70 go

Question 17

Results from experiment 1?

Answer 17

• Both groups were highly accurate with the GO trials.
• Low delayers committed more false alarms ( L= 14.5% H=10.9%)
• Similiar results for “cool” BUT low delayers did poorly in “hot”

Question 18

Results from experiment 2?

Answer 18

• No significant difference between two delay groups on reaction times
• Both high accuracy at correctly pressing button
• But Low delayers had higher false alarms in NoGo trials

-Low delayers showed LESS activity in RIGHT INFERIOR FRONTAL GYRUS during nogo trials.
But had HIGH activity in VENTRAL STRIATUM during no-go trials.

Question 19

The 3 conclusions made?

Answer 19

1) Resistance to temptation appears to be a relatively stable characteristic of an individual overtime.
2) Cognitive control can be strongly influenced by contextual factors (eg. hot cues - more tempting and so more predictive people’s behaviour)

3) Ventral Frontostriatal circuitry places a role in resisting temptation.
EG. low delayers have high activity in ventral striatum and low activity in frontal gyrus.

Question 20

Was the study valid?

Answer 20

exp 2 was more valid as extraneous variables were controlled to ensure IV is affecting the DV (carried out in laboratory) but exp 1 was carried out in homes where there could have been many distractions.

However LACKS IN ECOLOGICAL VALIDITY as the nogo/go task is artificial and also being in a fMRI scan is not realistic to everyday life.

Question 21

Was the study ethical?

Answer 21

Yes, informed consent was obtained and the fMRI scan is considered not harmful.
Participants were not in any harm.

Question 22

Was the study reliable?

Answer 22

Yes, use of fMRI scan means the results could be repeated with the same equipment and as it is taken place in laboratory, easy to replicate.

Question 23

What problems are there with the sample?

Answer 23

All from same nursery and a SPECIFIC TIME PERIOD.

Also the number of high delayers to low delayers are different.