Core studies - Biological Psychology - Casey study Flashcards
What is delayed gratification
Being able to resist temptation and hold off for a greater reward in the end, rather than a smaller reward immediately
Aim
To build on previous research to assess whether delay of gratification in childhood predicts impulse control activities when the participants were older
Sample
- P’s were taken from the original delay gratification experiments conducted in the 1960s / 1970s
- 59 p’s
- Mixture of high and low delayers
- High delayers: 20W, 12M, mean age 44..6 years
Low delayers: 16W, 11M, mean age 44.3 years
Research Method
-Quasi experiment
-Longitudinal study
What was the IV
Whether a p was a high or low delayer
What was the DV
-Performance on impulse control task (go/no go task).
-Imaging from and fMRI scanner was also
measured.
What materials were used in Experiment 1
- NimStim set of faces with ‘cool’ stimuli ( neutral faces), and ‘hot’ stimuli (happy or fearful faces)
What was the procedure in Experiment 1
- P’s were asked to complete a go/no-go task in their homes
- P’s completed a COOL and HOT version of this task
- P’s were instructed to respond as quickly as possible and as accurately as possible
- A face appeared for 500 milliseconds followed by a one second interval
- A total of 160 trials were presented per run in a pseudorandomised order
Results from Experiment 1
- There were no significant differences between high and low delayers in terms of reaction times during the trials. There was also no significant difference in terms of accuracy on all of the go trials ( 99.8% COOL, 99.5% HOT)
- There were significant differences on the no-go trials. The mean false alarm rate for the COOL task was 9.96% and for the HOT trials 12.2%
- Low delayers performed worse on the HOT task and happy faces acted as the main stimuli to cause false alarms
Key finding from Experiment 1
There were significant differences on the no-go trials. The mean false alarm rate for the COOL task was 9.96% and for the HOT trials 12.2%
Conclusions for Experiment 1
- Individuals who had difficulty delaying gratification at age 4 showed more difficulty as adults supressing responses to happy stimuli
- The results are consistent with the previous work: the context affects how easy it is to delay gratification. The more tempting the cause (e.g ‘hot’ faces) the harder it is to resist
Sample in Experiment 2
27 p’s from experiment 1
What materials were used in Experiment 2
- Objective E-Prime Software to display the task onto a projection screen
- Neuroscan 5 button response pad
- fMRI scanner which measures brain activity
What was the procedure in Experiment 2
- While in the fMRI scanner, p’s only completed the ‘hot’ version of the go/no-go task
- The stimuli and instructions were identical to those used in experiment 1 however there were differences in the timing and number of trials
- There were 2 runs, one with a happy face and one with a fearful face
Results from Experiment 2 (Quantitative)
- The accuracy rates for the hoot task were consistently high for the go trials with an average correct hit of 98.2%
- The performance was more mixed on the no-go trials with an average 12.4% false alarm rate
- Low delayer p’s had more false alarms (14.5%) than high delayers (10.9%) however this difference was not statistically significant
What is the significance of high activity in the Right Inferior Frontal Gyrus
High activity in this area means that the individual can withhold a response so is a high delayer
What is the significance of high activity in the Ventral Striatum
This area of the brain is responsible with rewards. High activity in this area means that a person is most likely a low delayer who cannot delay their gratification
Imaging results from Experiment 2 (Right Inferior Frontal Gyrus)
Compared to high delayers, low delayers showed a reduced level of activity in this area when giving correct ‘no-go’ responses
Imaging results from Experiment 2 (The Ventral Striatum)
Low delayers have increased activity in this area of the brain compared to high delayers
Key Findings
- Compared to high delayers, low delayers showed a reduced level of activity in this area when giving correct ‘no-go’ responses
2.Low delayers have increased activity in this area of the brain compared to high delayers
Conclusions for Experiment 2
- The results support the view that the frontal region of the brain is active when resisting temptation on a go/no-go task, and the activation is reduced in low delayers
- The ventral striatum showed exaggerated activity in low delayers: the more alluring the stimulus, the more low delayers were able to resist
- Different regions of the brain have more activity for cool and hot systems
Overall Conclusions
- Environmental hot cues plays a significant role in an individual’s ability to supress actions towards alluring cues
- Resistance to temptation is a relatively stable individual difference that predicts reliable biases in terms of brain activity
- Individuals who at age 4 have difficulties delaying gratification have difficulty as adults in terms of supressing responses to positive social cues
Key overall conclusion
Individuals who at age 4 have difficulties delaying gratification have difficulty as adults in terms of supressing responses to positive social cues
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