Child Topic 2: Pre-adult brain development Flashcards
Barkley-Levenson and Galvan aim
-To find out if there’s a difference in neuron activity between adults and adolescents brains when given risk-taking scenarios with different expected outcomes of those gambles
Barkley-Levenson and Galvan sample
-19 right handed adults aged 25-30 from the USA, 11 female, 8 male
-22 right handed adolescents ages 13-17 from the USA, 11 female,11 male
-Internet and poster advertisements through the university of California, as well as a database of participants from previous research
Barkley-Levenson and Galvan method
Participants had an intake session where they:
-Gave info about their monthly income and the spending of the money
-Mock fMRI scan to acclimatise participants to what it was like
-Given $20 for taking part and told they would use this as ‘playing money’ during the fMRI task on the subsequent laboratory session
-Told the’d be able to win up to $20 more but also, they could lose the whole of the $20
-1 week later they took part in a euro-imaging session
-During the fMRI scan they did the computerised gambling task, across 192 trials
-For each trail they had to decide if they were willing o play that particular gamble for real money, they indicated through a 4 point scale with 1 accept and 4 reject.
-Told that one of he gambles would be taken as their real trial and would determine how much money they were left with
-For each trial participants would see a spinner on the screen with two options
-Each option had either a sum of between -$20 and +$20
-For 24 of the trials, both options involved a loss, the other 144 involved a gain and one option entailed a lose, the size of the gains and loss varied each time
-Across the trials there was a balance of of gains and losses of the same sizes
Barkley-Levenson and Galvan results
Behavioural:
-Where no risk was involved e.g. a gain only or lose only, both groups made similar judgements
-An increased expected value increased the likelihood of both groups accepting the gamble
-However, adolescents were more likely than adults to accept gambles involving higher EVs
Neural:
-The ventral striatum was the region of the brain most interesting to the researchers
-The fMRI data showed more activation of the VS in adolescents as EV increased
Barkley-Levenson and Galvan conclusions
-Adolescents place greater value on rewards then adults do
-Neural representations of value in adolescents are linked to increased risk taking behaviour
Synaptic pruning
-Synapic togenesis is the process by which new shapes are formed between neurons
-Exuberaant synaptogenesis is the idea that 1 million new synapses are created each second, by the time of birth, following a genetically programmed plan to produce many more synaptic connections than necessary; after 3 years there follows process of synaptic loss
-Synaptic loss ‘fine tunes the brain structure and functioning; working using the ‘use it or lose it principal’ meaning inactive synapses die off
-synaptic pruning creates organisation in the brain, so areas become specialised for certain functions and are therefore more efficient
Mauro-Martin - Omega 3
-It was found that after an 8 week period of dietary intervention involving omega 3 supplements, Children with ADHD had reduced impulsiveness
DeBellis- stress on children’s brains
-It was suggested that stressful times may damage the pre-frontal control system
-This means the pre frontal cortex cannot reach maturity and reduces its moderating influence on the ventral striatum in adolescents resulting in more risk taking behaviours being carried out
-MRI scans on 44 adolescents and children with PTSD following maltreatment a decreased total area of the corpus callosum compared to control group
-Male children with pTSD had a smaller corpus callosum and general total brain volume than females with PTSD
-The intercranial volume was generally 7% smaller, for both genders, than the control group.
Graduated driving licenses
-Already in place in many countries across the world
-The idea is that you have different stages of driving and different stages you get different restrictions listen making the process more graduated
-In New Zeland it has reduced crashes for 15-19 year olds by 23% and 12% for 20-24 year olds
-16 year old drivers in the US who are subject to GDLs have 37% few crashes per year and 17% fewer crashes per mile driven
3 points for methodical issues for research into pre adult brain development
-Research is ethical if you have consent
-Research often controls for extraneous variables
-Research can be ethnocentric
3 points for nature-nurture debate for research into pre adult brain development
-Can be explained by nature if it looks at brain activity
-Can be explained by nurture if we’re looking at effects of upbringing or social factors
-Can support nature if it looks at brain development
3 points for individual-situational debate for research into pre adult brain development
-Can be explained by situational factors if it looks at the effect of diet
-Can be explained by situational factors if it looks at effects of stressful situations
-Can be explained by individual if it looks at the brain’s maturation affecting risk taking behaviours
