C3: Child Psychology Flashcards
Barkley-Levenson: aim
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.
Barkley-Levenson: research method
Quasi experiment with independent measures in a lab environment
Barkley-Levenson: hypotheses
1) Adolescents will exhibit greater behavioural sensitivity to increasing expected value than adults
2) Neuro-biologically ventral striatum activation will modulate in proportion to increasing expected value more for adolescents than adults
3) Adults who behave like adolescents in terms of gambling behaviour will not exhibit hyperactive stratal activation
Barkley-Levenson: dependent variable
Was the performance on a sample mixed gambles game during an fMRI scan
Barkley-Levenson: independent variable
Whether the participant was an adult or an adolescent and therefore it was naturally occurring
Barkley-Levenson: secondary analysis
Conducted to test the hypothesis that an exaggerated ventral striatum activation in adolescents would be observed even after matching adolescents and adults on subjective valuation (acceptance of gambles)
Barkley-Levenson: participants
- 19 healthy right handed adults between the ages of 25-30, with a mean age of 27.9 years old (11 females, 8 males)
- 22 healthy right handed adolescents between the ages of 13 and 17 years old, with a mean age of 15.6 (11 females, 11 males)
- All participants had reported no psychiatric or neurological illnesses or developmental delays and had no metal in their bodies, not taken psychoactive medication
Barkley-Levenson: how were participants recruited
Through posters and internet advertisements approved through the University of California (UCLA) Institutional Review Board and through a database of prior research participants
Barkley-Levenson: procedure
- Participants attended an intake and neuro-imaging session in the lab where asked to sign consent forms and provide primary source of income and amount of spending money per month
- Significant different in the amount of money adolescents and adults had per month
- Participants then familiarised with MRI scanner and awarded $20 for completing the intake session
- They were told the money given is ‘playing money’ where there was a possibility of earning more or losing it all
- One week after the participants has taken part in the intake, they were asked to return for their fMRI scans, this used a 3-Tesla Siemans Trio MRI machine
- During this, participants asked to complete a gambling task where they were presented a series of gambles with a 50% probability of gaining/losing the amount
- The side of the spinner on which the gain and loss appeared and the order of the stimuli was counterbalanced across participants, and for each trial, participants decided whether or not they would be willing to play that gamble for real money.
- Participants extensively trained before the scan to make sure they understood all aspects of the gambling task
Barkley-Levenson: qualitative results
- Acceptance rates did not change in adults and adolescents where there was no risk involved
- All participants more likely to accept a gamble where the expected value was positive
- Positive expected value had a bigger impact on adolescents than adults, this was a significant difference showing a stronger influence on gambling choices of adolescents and greater activation of the ventral striatum.
- No significant difference in reaction times and on gain-only or loss-only trials.
Barkley-Levenson: conclusions
- 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.
- Not the money as a reward that caused the differences in responses but rather the differences in the valuation of money which is affected by our brain activity.
Van Leeuwen: aim
To investigate whether biological factors and/or environmental factors affect intelligence using twins, parents and siblings
Van Leeuwen: research method
Series of mini case studies and a correlational study
Van Leeuwen: participants
112 families from the Netherlands were studied through Twin Registry from the VU University of Amsterdam
- Families with twins and an extra sibling between the ages of 9 and 14 and both parents were selected to take part in the study
- Initially, 214 families were contacted via letter sent out two months before the twins 9th birthday, followed by an phone call two weeks later
Van Leeuwen: characteristics of participants
- 23 pairs of male monozygotic twins
- 23 pairs of male dizygotic twins
- 25 pairs of female monozygotic twins
- 21 pairs of dizygotic female twins
- 20 pairs of dizygotic pairs of opposite sex twins
- Mean age of twins was 9.1 years
- Mean age of siblings was 11.9 years
- Mean age of biological mother was 41.9 years and for biological fathers was 43.7 years
Van Leeuwen: procedure
- All parents sign consent forms for children and themselves, children also signed consent forms
- Study was approved by the Central Committee on Research involving Human Subjects
- Parents told they were compensated for any travel expenses incurred and that all children took part would receive a present
- Families took part in a number of measures including MRI scans, cheek swabs and cognitive testing
- All childrenn tested in separate rooms using Raven’s Standard Progressive Matrices (SM)) at their own pace after verbal instructions given
- Parentd asked to complete the Raven Advanced Progressive Matrices (AMP) using written instructions at own pace
- Procedure took around 5 hours with two short breaks and a longer lunch break
Van Leeuwen: Raven’s Standard Progressive Matrices
- 60 problems divided into 5 sets of 12
- In each set the first problem is as newly as possible self-evident and then the problems becoming progressively more difficult
- Provides an index of general intelligence
Van Leeuwen: Raven’s Advanced Progressive Matrices
- Administeres to adults as the SMP is too easy
- Test is comparable with the SMP but more difficult
- Set 1 has 12 practice items to familiarise the participants with the test
- Set 2 conssists of 26 items which are identical in presentation and argument to those in set 1
- The items progressively get more difficult and complex
Van Leeuwen: number or participants in each condition and the mean scored
Fathers = 94, 27 Mothers = 95, 25.9 Male siblings = 44, 43.8 Female siblings = 57, 46.4 Male twins = 114, 36.7 Female twins = 110, 36.6
Van Leeuwen: maximum score for parents and children
Parents = 36 Children = 60
Van Leeuwen: key findings
- No sex differences found in intelligence
- Correlations higher in monozygotic twins than for any other first degree relative
- More variance in siblings IQ in twins even through the same test was used, cannot be fully explained by age
- Genetics accounts for 67% of variation in intelligence and the remainder is due to random environmental issues
- For lower IQ groups, interaction between genetic make up or genotype and environment was higher
Van Leeuwen: conclusions
- Variability in fluid intelligence (as measured by Raven) is largely explained by genetic effects that are passed from parents to children
- Individual differences in intelligence are largely accounted for by genetic differences
- Environmental factors are significantly more important in children with a genetic predisposition for a lower IQ
Gibson and Walk: aim
To Investigate the age at which young children start to show the ability to use visual stimuli to be able to discriminate depth and the recording of receding distance. They wanted to show support for the idea that humans and other species depth perception is innate and therefore they know not to crawl or walk over a visual cliff end
Gibson and Walk: research method
Lab experiment
Gibson and Walk: experimental design
Repeated measures
Gibson and Walk: independent variable
Whether the young child was called by its mother from the cliff side or the shallow side of the visual cliff apparatus
Gibson and Walk: dependent variable
Whether or not the child would crawl to its mother
Gibson and Walk: animal research method
Quasi lab experiment