Biological-Casey

Question 1

Background

Answer 1

Delaying gratification (self-control) means resisting temptation for a reward later.

Based on Mischel’s marshmallow test (kids who resisted eating a marshmallow had better self-control later in life).

Previous studies linked low self-control to differences in brain activity, especially in the prefrontal cortex (self-control) and ventral striatum (reward processing).

Casey et al. wanted to see if self-control in childhood predicts brain activity and behavior in adulthood.

Question 2

Study 1- Aim

Answer 2

Whether people who had difficulties delaying gratification at the age of of 4 had problems 40 years later

Question 3

Study 1- Sample

Answer 3

• People who participated in the marshmallow test last time
  -27 low delayers 32 high delayers
  -59 people all aged 44

Question 4

Study 1- Procedure

Answer 4

59 adults (who did the marshmallow test as kids) completed a Go/No-Go task (testing impulse control).

Shown faces on a screen:
Go (press button) – when a certain face appeared.

No-Go (don’t press) – when another face appeared.

Two conditions:
“Hot” task – emotional faces (e.g., happy).
“Cool” task – neutral faces.

Question 5

Study 1 -Findings

Answer 5

Low delayers (poor self-control as kids) made more mistakes, especially in the hot task (happy faces).

Low delayers had less activity in the prefrontal cortex (self-control).
More activity in the ventral striatum (linked to rewards).

Question 6

Study 1 -Conclusions

Answer 6

Self-control is stable over time – those with low self-control as children still struggled as adults.
Impulse control is harder when emotions (rewards) are involved.
Brain differences explain why some people find it harder to resist temptation.

Question 7

Study 2- Aim

Answer 7

If there is a brain based explanation for the ability to delay gratification

Question 8

Study 2-Sample

Answer 8

-27
-11 low 15 high

Question 9

Study 2- Procedure

Answer 9

Repeat- Go/No Go task
done inside fMRI scanner

Question 10

Study 2- Findings and conclusions?

Answer 10

Findings:

Low delayers (poor self-control) had:
Less activity in the prefrontal cortex (self-control area).
More activity in the ventral striatum (reward-related area), especially for happy faces.

Conclusions:

Self-control is linked to brain activity—people with poor self-control have different brain responses.
Resisting temptation is harder when rewards (emotions) are involved.
Brain function differences may explain why some people struggle with impulsivity in daily life.