Flashcards in Casey et al. (2011) Deck (22)
What are high and low delayers?
A high delayer is someone who can resist temptation. A low delayer is the opposite.
What is the centre in the brain for deciding whether to resist temptation or not?
The Inferior Frontal Gyrus.
What is the centre in the brain which deals with rewards and desire?
The Ventral Striatum.
What were the main 3 aims of Casey's study?
Casey aimed to find out if participants who were low delayers on the Marshmallow Test at age four:
-would show more errors on a Go/No-Go task if the stimuli were 'hot' than high delayers
-would show lower activity in their Inferior Frontal Gyrus than high delayers
-would show increased activity in their Ventral Striatum than high delayers
How were the participants brain activity observed?
Using an fMRI scanner.
What is a 'hot' task and a 'cool' task?
A hot task is one which stimulates the centre of reward and desire in the brain (the Ventral Striatum). A cool task is one which stimulates the centre of delay of gratification in the brain (the Inferior Frontal Gyrus)
How many participants were in the original study on the Marshmallow test when they were age 4?
How many participants were in the follow up and what did they complete?
155 adults completed self-control self-reports, which identified which participants were 'low-delayers' and which were 'high-delayers'.
How many participants were in the main study?
59 participants of the original 562 agreed. (27 low-delayers and 32 high-delayers).
What is a Go/No-Go task?
Go/No-Go tasks are used to measure people's response control (e.g. a task requiring a participant to perform an action given a certain stimuli such as press a button).
How many Go/No-Go tasks did participants complete in experiment one?
They completed four Go/No-Go tasks, consisting of faces flashing up on a screen for 500ms, with 1-s intervals between faces.
What were the 2 'cool' versions of the Go/No-Go tasks in experiment 1?
Having to press the button whenever a male neutral face appeared, and the next task was to press a button whenever a female neutral face appeared.
What were the 2 'hot' versions of the Go/No-Go tasks in experiment 1?
Having to press the button whenever a happy facial expression appeared, and the next task was to press a button whenever a fearful facial expression appeared.
What were the results of experiment 1?
-Both groups of participants performed with high level of accuracy on the 'Go' trials in both 'cool' and 'hot' versions.
-Both groups made more errors on the No-Go tasks
-Low delayers made more errors on the 'hot' No-Go task.
What do the results of experiment one conclude?
They conclude that low delayers who had shown more difficulty in delaying gratification at age four showed more difficulty suppressing responses to happy faces in their forties - low self-control remains consistent through life.
How is an fMRI scan different to an MRI scan?
A functional-MRI scan is designed to look at how the brain works rather than it's structure.
How many participants were in experiment 2?
27 of the 59 participants were used in experiment 2. 15 were high delayers and 11 were low delayers.
What kind of task did participants complete in experiment 2?
A 'hot' Go/No-Go task similar to the one in experiment 1.
Which 3 ways did the 'hot' Go/No-Go task in experiment 2 differ from experiment 1?
-2-14.5s delay instead of 1s delay.
-48 trials per run (35 'Go' and 13 'No-Go'), giving 70 'Go' and 26 'No-Go' trials for each expression - fearful and happy
-Apparatus different as participants presented stimuli on a screen in the scanner
What were the results of experiment 2 to do with the 'Go' trials?
Both groups scored highly on the 'Go' trials, and the low delayers showed more false alarms.
What did the fMRI scanner find during the trials?
-Low-delayers showed lower activity in the right inferior frontal gyrus than high-delayers on the No-Go trials.
-Low-delayers showed higher activity in the ventral striatum, specifically when the 'happy' faces were the No-Go stimuli.