key research (part A)

• aim


  Barkley-Levenson's study allows us to study whether teens attribute greater values to rewards or whether the value of money is greater due to the fact that typically they have less access to it and experience with it
• hypotheses

  1. adolescents will exhibit greater behavioural sensitivity (accept more gambles) to increasing expected value than adults
  2. neuro-biologically, ventral striatum activation will modulate in proportion to increasing expective value more adolescents than adults
  3. adults who behave like adolescents in terms of gambling behaviour will not exhibit hyperactive striatal activation.
• research method


  quasi-method

  independent measures design

  laboratory conditions
• independent variable


  whether the participants was an adult or an adolescent and therfore it was naturally occurring
• dependent variable


  was the participants performance on a sample mixed gambles game during FMRI scan
• participants


  recruited through posters and advertisements.

  UCLA

  19 healthy right handed adults

  22 healthy right handed adolescents (13-17)

  no reported psychiatric or neurological illnesses
• procedure 


  all participants signed a consent form. asked to provide their primary source of income and amount of spending money a month (adolescents on average had $52.50 and adults had $467.11).given $20 spending money, told they could win up to 100% more but there was a possibility of losing 100% of it.
• results

  • the acceptance rates did not differ between adolescents or adults when there was no risk involved
  • all participants were more likely to accept a gamble when the expected value was positive, and there was no significant difference in the percentages of trial accepted (positive, negative or zero value) between adolescents and adults.
  • no significant difference in reaction times on gain-only or loss-only trials
• conclusions


  Barkley-Levenson et al. suggests that adolescents risk taking behaviour is affected by the activity in the ventral striatum, as teens showed more activity in this area as the expected value increased, and this is something that changes over time through neural development.