Casey

• background


  • Mischel et al Marshmallow test: testing the willpower of children by leaving them alone with a marshmallow and telling them if they do not eat it they will get two instead of one
• aims


  • to see if low delayers on the marshmallow test at age 4 still struggled with resisting temptation in adulthood
  • to examine activity in areas of the brain thought to be associated with the ability to resist temptation
• sample


  • 562 four year olds took part in the initial marshmallow test
  • they followed up in their 20s using a self-report measure (some dropped out)
  • followed up again in their 30s using a self-report measure
  • consistently high or low delayers were contacted again in their 40s to take part in this study
• procedure


  • cool task: participants completed an impulse control task called the No-Go/Go task, they would have to press a button when they saw one stimulus and not press a button when they saw the other stimulus (e.g. male vs female)
  • hot task: faces with happy expressions acted as 'hot' stimuli, participants were shown happy or fearful faces and had to press a button when they saw one type of emotion
  • participants did 4 sets of 160 faces, 2 cool, 2 hot
  • experiment 2 (measuring brain activity) was a very similar procedure, but participants did the tasks whilst getting an fMRI
• results


  • there was no difference between high and low delayers on the cool task, similar amounts of errors were made
  • low delayers made more errors than the high delayers on the hot task
  • low delayers made significantly more errors on the hot task than they did the cool task
  • low delayers showed lower activity in the right inferior frontal gyrus than the high delayers
  • low delayers showed higher activity in the ventral striatum than high delayers
• conclusions


  • low delayers showed more difficulty suppressing responses to happy faces in their forties, suggesting that low/high self-control is a fairly constant trait in individuals
  • being able to delay gratification is a useful ability that can help with long term decision making and goals
  • low delayers showed less activity in inferior frontal gyrus and more in ventral striatum which suggests a biological reason why some people have better self-control than others