extra research

• Casey (2011)


  this quasi experiment measured brain activity differences between high and low delayers to see which regions of the brain were involved in delay of gratification. Casey found that low delayers had higher activity in their ventral striatum and lower activity in their inferior frontal gyrus and ventral striatum. these brain differences can explain why low delayers found it harder to delay their gratification as they had more activity in the reward based parts of their brain and less activity in their decision making part of the brain
• Eschel et al (2007)


  used FMRI to measure brain activity when completing a Wheel of Fortune task which is a computerised two-choice decision-making task involving probabilities of winning and losing high or low value sum sof money. the sample consists of 18 healthy adolescents aged 9-17 and 16 healthy adults aged 20-40. all participants were right handed. it was found that there was more brain activity in the frontal cortex in adults compared to adolescents when they made a riskier financial choice. this shows the prefrontal cortex was not fully developed.
• Johnson et al (2006)


  found that changes in the ventral striatum almost exactly matched the increase in arrests for criminal behaviours (such as drug-taking) that peaks into late adolescence. interestingly, there was a sex difference for females, the peak was 16 years but for males it was 19. one consequence of this is that behaviour in adolescence is more impulsive than it is in childhood or adulthood