Background: Aim: Validity :
-Delay of Gratification = ability to delay To investigate if people who were -Lacks ecological validity as go/no-go tasks were artificial and unlike what
pleasure low delayers in marshmallow task, real encounters of facial and eye expressions would be like.
-Marshmallow test = To see if children are high would have low self-control (delay
or low delayers by eating or not eating gratification) in their 40’s. -Also, the use of FMRI may have given unnatural responses as ppts may
marshmallows in front of them. To investigate what regions of the behave differently in social situations.
Used idea of cooling strategies. brain, predict self-control.
-Metcalfe and Mishel = suggested there are a Reliability:
cooling system in pre-frontal cortex. Method: -Lacks external reliability as the study was longitudinal so harder to
-Inferior frontal gyrus is more active in high -Quasi experiment replicate again outside the study as it looks place over many years.
delayers. -IV’s = high delayers and low
-Ventral striatum is more active in low delayers. delayers +High in external reliability as the use of the FMRI would produce similar
Repeated measure design results if the study was replicated.
Sample: -DV = If low delayers made more
-59 ppts with 27 low delayers and 32 high errors with hot stimuli. +High internal reliability as there were standardised controls and
delayers. -DV = Activity in target areas of the instructions on how to complete tasks and for how long each stimulus
-26 ppts with 11 low delayers and 15 high brain. appeared for.
delayers. Casey et al.
Procedure exp 2:
Procedure exp 1: Did same task.
-Self-control measured by go/ no-go tasks. Used FMRI (physiognomy) and an
Required ppts to push button when they saw a MRI to measure brain activity.
certain stimulus (go task). 27 out of 59 agreed
-Hot cue = happy face. 1 male was excluded due to poor
-Cold cue = neutral/ fearful face. task performance.
Each ppts did 4 of these tasks at home
on a laptop delivered to the house. Conclusions:
Each face appeared for ½ a second with -Resisting temptation is a
1s intervals. stable individual Ethics:
-Instructions appeared on screen. characteristic -Could have caused psychological harm, as low delayers may have
-Delay of ability is experienced lowered self-esteem from being labelled low delayers.
Results hindered by alluring cues -Gave informed consent
-Ppts able to delay gratification as children, showed and not a general -Use of FMRI and MRI raises issues of physical harm as they are very noisy,
greater ability to supress impulses. problem with cognitive and this may have been unpleasant for ppts and difficult to withdraw once
-No sig diff between high/ low delayer in reaction times. control. scanning has begun.
-low delayers made more errors on hot tasks -Empirical evidence for -Not deceived as told what was going to occur during informed consent.
-Both scored highly on accuracy. Mischel and Metcalfe’s -Confidentiality was not breeched.
-Low delayers showed more false alarms hot and cold processing -Right to withdraw
-Low delayers showed reduced activity in right inferior system that the brain
frontal gyrus and high activity in ventral striatum. affects control.
-Delay of Gratification = ability to delay To investigate if people who were -Lacks ecological validity as go/no-go tasks were artificial and unlike what
pleasure low delayers in marshmallow task, real encounters of facial and eye expressions would be like.
-Marshmallow test = To see if children are high would have low self-control (delay
or low delayers by eating or not eating gratification) in their 40’s. -Also, the use of FMRI may have given unnatural responses as ppts may
marshmallows in front of them. To investigate what regions of the behave differently in social situations.
Used idea of cooling strategies. brain, predict self-control.
-Metcalfe and Mishel = suggested there are a Reliability:
cooling system in pre-frontal cortex. Method: -Lacks external reliability as the study was longitudinal so harder to
-Inferior frontal gyrus is more active in high -Quasi experiment replicate again outside the study as it looks place over many years.
delayers. -IV’s = high delayers and low
-Ventral striatum is more active in low delayers. delayers +High in external reliability as the use of the FMRI would produce similar
Repeated measure design results if the study was replicated.
Sample: -DV = If low delayers made more
-59 ppts with 27 low delayers and 32 high errors with hot stimuli. +High internal reliability as there were standardised controls and
delayers. -DV = Activity in target areas of the instructions on how to complete tasks and for how long each stimulus
-26 ppts with 11 low delayers and 15 high brain. appeared for.
delayers. Casey et al.
Procedure exp 2:
Procedure exp 1: Did same task.
-Self-control measured by go/ no-go tasks. Used FMRI (physiognomy) and an
Required ppts to push button when they saw a MRI to measure brain activity.
certain stimulus (go task). 27 out of 59 agreed
-Hot cue = happy face. 1 male was excluded due to poor
-Cold cue = neutral/ fearful face. task performance.
Each ppts did 4 of these tasks at home
on a laptop delivered to the house. Conclusions:
Each face appeared for ½ a second with -Resisting temptation is a
1s intervals. stable individual Ethics:
-Instructions appeared on screen. characteristic -Could have caused psychological harm, as low delayers may have
-Delay of ability is experienced lowered self-esteem from being labelled low delayers.
Results hindered by alluring cues -Gave informed consent
-Ppts able to delay gratification as children, showed and not a general -Use of FMRI and MRI raises issues of physical harm as they are very noisy,
greater ability to supress impulses. problem with cognitive and this may have been unpleasant for ppts and difficult to withdraw once
-No sig diff between high/ low delayer in reaction times. control. scanning has begun.
-low delayers made more errors on hot tasks -Empirical evidence for -Not deceived as told what was going to occur during informed consent.
-Both scored highly on accuracy. Mischel and Metcalfe’s -Confidentiality was not breeched.
-Low delayers showed more false alarms hot and cold processing -Right to withdraw
-Low delayers showed reduced activity in right inferior system that the brain
frontal gyrus and high activity in ventral striatum. affects control.
