bio - casey

• Research method + Evaluation

  longitudinal study, tracking the same participants from age 4 to their 40s

  allowed researcher to conclude that ability to resist temptation is a stable charactersistic and some are good at it and some are not

  
  

  (-) affected by subject attrition and take along time to conduct

  
  

  Composed of two natural/ quasi experiments - participants conducted experiment 1 in their own home on computer

  
  

  (+) highly controlled environment

  use of fMRI to measure brain activity gave detailed observation of areas controlling self control and reward - enables to draw conclusions
• Casey IV and DV and how was it measured

  IV - the individual participants ability to delay gratification; operationalised as high or low delayers

  
  

  DV: Performance on an impulse control task (go/no go task)

  measured in terms of reaction times and accuracy.

  Imaging from an fMRI scanner was also measured
• Casey Participant Sample


  562 pupil aged 4 drawn from an initial cohort that completed the original delay of gratification task

  
  

  59 (23 male and 36 female) took part in Experiment 1

  
  

  27 ( 13 males and 14 females) took part in Experiment 2

  
  

  - study suffers from subject attrition!!
• Procedure Experiment 1


  - sample was divided into high delayer and low delayers

  
  

  - participants took part in a behavioural version of a 'hot and 'cool' impulse control task, which they completed on pre programmed laptop at home

  
  

  - completed two versions of 'go/no-go' task in which participants were instructed to either:

  press a button ( go )

  or withhold a button press (no-go)

  
  

  - the 'cool' version of the task - male and female faces with neural expressions; one sex was the go stimulus and the other the no-go stimulus > this was used because there is no emotive or impulsive things about the images

  
  

  - the 'hot' version of the task - alternating happy and fearful faces (rewarding emotional faces) as they are classed as alluring stimuli

  
  

  - face appeared for 500 milliseconds

  
  

  hot and cool versions were chosen to explore the influence of alluring social cues. the two versions only differed in the use of happy expressions or neutral/ fearful expressions.
• Procedure Experiment 2


  Participants were scanned with a functional magnetic resonance imaging scanner while completing a hot version of the go/ no-go task via a rear projection screen.

  
  

  An electronic response pad was used to record responses to facial stimuli and reaction times as well as false alarms.
• Results experiment 1


  Experiment 1

  
  

  Low and High delayers were accurate in their correct responses to go trials in hot and cool conditions ( 99.8 % and 99.5% )

  
  

  
  

  Both groups made errors during no - go trials but low delayers were dominated in that, made more errors on hot tasks

  
  

  - Low delayers identified at age 4 showed greater difficulty suppressing their responses to happy faces than high delayers > shows that low self control remains consistent in an individual, self control depends on stimulus , low delayers had more difficulty on happy face hot task
• Conclusions


  Resistance to tempatation appears to be a relatively stable charactersistic of an individual over time

  
  

  cognitive control can be strongly influenced by contextual factors ( e.g. 'hot' cues ) in alluring situations

  
  

  ventral frontostriatal circuitry supports resistance to tempation, with a combination of lowered activity in the inferior frontal gyrus and increased activity in the ventral striatum in low delayers.
• what was measured in the initial task of 4 year olds

  the delay of gratification and if the person would be a low or high delayer
• identify the area of brains investigated and what their results show

  the inferior frontal gyrus located within the prefrontal cortex ( cognitive control that aids in gratification delay ) with holding response > low in low delayers high in high delayers

  
  

  
  

  the ventral striatum are related to hot cues involving immediate reward > high in low delayers , low in high delayer
• fMRI scan - experiment 2 results

  No go trials in hot version ( facial expression of happy and fearful )

  
  

  Low delayer - high activity in ventral stratium and low activity in inferior frontal gyrus

  
  

  High delayers - low activity in ventral stratium ( reward region ) and high activity in inferior frontal gyrus ( withholding response )

  
  

  no significant difference between two delay groups on reaction times to go trials

  
  

  low delayers had higher false alarm rates in no-go trials 14.5% compared to high delayers 10.9%
• what are hot and cold cues ?

  
  

  how to resist temptation


  hot cues are aspects of something that make it attractive

  
  

  cold cues are aspects that are not appealing such as the shape of a biscuit

  
  

  to help resist temptation focusing on the cool cues is important
• what is impulse control

  the ability to resist the desire of immediate gratification
• AREA


  Biological - behaviour has a phsysiological cause

  
  

  lies in differences in brain structures, genes hormones affecting the brain

  
  

  categorises into biological area as it investigates whether there are specific regions of the brain that impacts our ability to resist temptation of rewarding stimuli. > shows that biological factors play significant part in our ability to defer gratification

  
  

  
  

  Individual differences - there are individual differences present from our childhood and stables across decades
• INSURED


  I - there are differences in individuals ability to resist temptation during alluring social cues. in the ways they respond to "hot" cues and temptation -

  
  

  
  

  N - Nature > study argues the influence of individual differences in brain function and resulting impulsive behaviour. however, the fact that low and high delaying participants were from - only used people at both ends of the scale, others who might show their ability to resist temptation as they got older were excluded as they weren't at the extreme end of the scale from the study and so nature may have played a big factor

  
  

  S - very scientific, Mri objective way of collecting data and observing brain activity which is not open to bias, standardised procedure....

  
  

  U - how we resist and increase success

  Cool cues focusing

  
  

  R - reduce behaviour down to one factor. In this case resisinting to temptation is reduced to brain activity while it may have to do with other factors such as cognitive factors, mental thought processes or upbringing, developmental

  
  

  E - ethical as participants were informed, withdraw which many participants used seen in sample reduction

  
  

  D -deterministic, imply imposes the idea that if you are a low delayer you will have a hard time resisting temptation in adult hood
• Usefulness and Practical applications

  Casey shows that resisting tempation in favour of long term goals is important for individuals societal and economic functioning

  
  

  better coping in adolescence and also protects against physical and mental health problems - drug use

  
  

  create strategies to train brains of low delayers aged four years might help to protect them from vulnerability to problems in later life
• Psychology as a science


  controlled laboratory experiment fulfills scientific criteriaof theory, control, evidence and replication
• Nature Nurture debate


  Suggests that interventions may improve ability of low delayers to defer gratification
• Determinism


  Suggests brain differences mean that some are good and some are some are vulnerable to gratification
• Reliability


  + consistency

  
  

  (-) high subject attrition from 562 to 26 , unequal number of trials means unable to generalise findings
• Validity

  
  

  Ecological Validity


  (+)high design and internal validity as study is controlled

  
  

  (-) does not tell us how people normally respond under normal conditions > real life social interaction are more complex and may cause our brain to behave differently

  
  

  fMRI scan while test does not resemble true life and could have had an impact on performance
• Sample Ev

  (-) subject attrition

  
  

  all participants attended one nursery and so does not represent other areas or backgrounds
• Type of Data


  (+) quantitative data - numerical values easy to compare , easy to summarise in graphical form
• Describe the initial task given to children at age of four and explain what it measures

  Self control was tested in marshmellow test

  
  

  children brought into room with marshmellow on table , told that they could eat marshmellow or wait and then have two , researcher left room for 15 minutes

  
  

  performance on test showed that those who could wait were high delayers and able to defer gratification and those who didnt were low delayers
• How does fMRI scan work and what was the purpose of using it in the study

  fMRI scans are designed to investigates how the brain works ( brain activity )

  
  

  used to test hypothesis that ventral stratium regulates rewards and frontal gyrus regulates delay of gratification
• Differences and Similarities in Casey and Sperry

  S - both investigated how different parts of the brain affected our behaviour, lab experiments

  
  

  D - not longitudinl study