SPRING The Adolescent Brain Flashcards
galvan et al 2007 risk taking describe
risky beh in children teens and adults
assess risk taking, impulsivity and risk perception via Qs
then delayed response reward task
- cue assoc with specific reward and cue on specific location - implicitly learn what reward linked to what cue
what is adolescence
between childhood and adulthood
onset of puberty
more sensitive to environment and more emotional/mood distrubances
describe the triadic brian (ernst, pine and hardin 2006)
changes in risk is a result in changes in the engagement between reward beh, avoidance and regulatory systems
PFC- regulation -assess signals in context, ensure making appropriate response
amygdala - role in fear, threat and emotion, vigilance and attend to environment (high activity = respond to threat)
ventral striatum (NA + VT role in DA)
- highly active then perceive event as rewarding
- areas work together to regulate risk and emotion
the triadic brain thought to be in teens
increase response of VS and decrease response of AMYG - more susceptible to reward and less susceptible to threat
PFC immature and connections weaker - less behavioural regulation, more likely to respond to immediate environement and bias risk assess
Somerville et al (2011) go no go risk and reward
6-19y/o in go-no-go paradigm and fmri using happy and neutral faces
happy face = social cue for reward
focus on frontostiatal circuitory and VS
difference in teens and children in inability to inhibit
children under parental control - ontrol by external mediators
teens no parental control - must learn to conrol by themselves and therefore make sig rise in risk/response to happy faces
+ diff in structure and function of brain due to dev
Casey et al 2008 development of the PFC and NA
greater NA activity in response to rewards in teens
less mature PFC response in teens and children > adults
diff dev trajectories
describe procedure van leijenhorst et al 2010 impulsivity and risk
fmri to test dev if changes in brain activation during decision is linear in dACC & LPFC but peak in vmPFC and VS
8-10,12-14,16-17 and 19-26y/os
two choice decision task chosing between high and low risk gamble (high = varied reward)
results van leijenhorst et al 2010 impulsivity and risk
risk increase when reward increase - not differ by age
decrease in risk taking with age when high risk lower (£2) - older more risk averse when reward is lower/more ambiguous
adults realise not necessary to tak high risk for low reward and earn more for low risk
young more high risk in low reward
ffmri results van leijenhorst et al 2010 risk and PFC/ACC
high risk>low risk = increase in mPFC, dPFC, vmPFC and ACC
low risk>high risk = increase right dlPFC- assoc with cog control and response inhibition
linear decrease in dACC with agg - assess error and pain recog- something gone wrong
describe fuzzy trace theory
in order to be good at something must develop expertise
adults get more experiece and therefore better at chosing the best outcome
fmri reward and control results van leijenhorst et al 2010 impulsivity and risk
gain > no gain in high risk
= active in mPFC and VS - peak in teens in caudate
gain>no gain in increasing reward outcomes
= active r.putamen, r.VS and NAcc
risk assoc with mPFC and VS (reward) and caution with dlPFC (cog control)
child age related decrease in dACC (control)
adolescence specific peak in vmPFC in decision making and VS in outcome
dorsal accuberns and subcallosal cortex results van leijenhorst et al 2010 impulsivity and risk
dACC - assessment of error and pain
- linear decrease with age - less likely to find error in actions as more expertise
subcallosal cortex - assoc with emotional responses, not linear, peak in teens
dreyfuss et al 2014 go no go on amyg and pfc
go no go on impulsivity to threat stimuli in 6-12, 13-17 and 18+
adolescents > false alarms than children or adults
failure to inhibit response to emotional stimuli- heightened sensitivity to emotional cues?
define adolescent emergent
linear development and plateau
gradual and maintained activity after adolescence
define adolescent specific
peak in adolescence - hightened response
dreyfuss et al 2014 go no go brain areas emergent
left premotor cortex
right anterior cingulate cortex
right inferior frontal gyrus
– regulate attention/ignore irrelevant info
dreyfuss et al 2014 go no go brain areas specific
left orbitofrontal cortex
left striatum
left mPFC
– reg of emotional and beh responses - especially to threat stimuli
limits of triadic brain model on teens
can be correct
where amygdala is thought to decrease actually increase response to threat as well as reward
limits of casey et al 2008 PFC and NA development (PFC linear NA earlier)
cant be correct
only reflects a response to reward and not to threat
describe the imbalance framework (casey et al 2016)
integrated circuit based perspective on development of self control
fine tuning of connections in complex cortical and subcortical PF and limbic areas
maturation of top down projections with age
describe albert et al 2013
effect of context on reward in the adolescent brain
adolescent increase risk if with peers
peer influence on adolescence
larson et al 1996
blakemore and mills 2014
bernott 1979
larson - opinions of peers more important than family
blakemore and mills - peer relations more rewarding so more influential on decision making processes
bernott- curvilinear conformity to peers between mid and late adolescence with peak in early
mood distrubances in adolescence
sebastian burnett and blakemore 2008
associated with the emergence of self concept and disproportionately enhances self awareness compared t childhood/adulthood
adolescent risk taking stats
eaton et al 2006
13000 asolescent deaths in USA
70% from motor vehicle crashes, unintentional injury, homocide and suicide
impulsivit and risk taking distinction
casey, getz and galvan 2008
teens stereotypically more impulsive and risk taking but not the same thing - distinct constructs with different developmental trajectories
impulsivity
casey getz and galvan 2008
acting without forethought
acting in a rapid and unplanned manner to internal or external stimuli without regard of possible negative consequences
developmental trajectory of impulsivity
casey getz and galvan 2008
diminished with age
associated with protracte edvelopment of the PFC
risk taking
casey getz and galvan 2008
act of doing something that involves danger or risk in order to achieve a goal
developmental trajectory of risk taking
casey getz and galvan 2008
increase in adolescence but lower in childhood and adulthood
associated with subcortical systems in the evaluation of rewards
Galvan et al 2007 risk taking procedure
three cues assoc with distinct reward value
indicate whether cue on left or right of screen then get high or low reward
implicitly learn reward assoc with different cues
galvan et al 2007 risk taking results
fMRI
anticipation of pos/neg reward assoc with NA and risk taking
expectation of neg = lower NA activity
expectation of pos = higher NA and more risk beh
dev shift: asolescence and adults increase risk if pos consequence
increase risk in adolescence may be related to increase response to immediate pos reward
x2 high risk teens - more NA response - indiv diff
schramm-sapyta et al 2004
sensitivity to reward due to hypersensitive reward system that influences reaction to drugs
adolescent rodents more locomotor activity than adults when exposed to cocaine and lower nicotine withdrawal
describe the go no go paradigm
inhibit typical response to stimulus ie happy face
and respond to stimulus that is neutral/would not usually elicit a response
misses - fail to respond in go trial (not respond to neutral)
false alarms - respond in no go (respond automatically to stimulus told to inhibit)
galvan et al 2006 frontostriatal maturation
VS show strong signalling in adolescence
may be indicative of early maturaion
dopamine rich brain region- represents the appetitive value of potential rewards
geid et al 1999 frontostriatal maturation
ventrolateral and frontostriatal networks less structurally and functionally mature in adolscence
assoc with integration of motivational and cog control processess
somerville et al 2011 frontostriatal and VS results
no sig effect of age on misses
teens sig more false alarms (respond to happy when should inhibit) - reduced capacity to suppress approach to salient appetitive cue
increase activity in VS in teens>child/adult (adol specific) - sig to happy> neutral faces - exagerated rep of reward in teens and top down reg likely to be protracted
evolutionary reasons for diff dev trajectories of NA and PFC
adolescence is time to seek independence ie leavve family, seek sexual partners etc so need to be more impulsive and risky in decisions in order to succeed
describe “cake gambling task” val leijenhorst et al 2010
chose between high and low risk gamble assoc with probabalistic monetary reward
4:2 wedges assoc with rewards
computer randomly selects wedge - if colour match that chosen then win gamble
probabilities kept constant but reward change:
high either £2, £4, £6 or £8 while low always £1
(66% win low, 33% win high)
dreyfuss et al gender
males influence energent specific response in adolescence
- more false alarms and increased OFC activation (approach beh)
females show more mPFC activity related to reg of avoidance beh
casey et al 2016 imbalance - role of mPFC
modulates activity of VS na damygdala
supress outputs leading to emotive responses/actions
casey at al 2016 imbanalce - role of VS
learning and prediction of reward outcomes
input from amyg - learn emotional sig of environmental cues - facilitates VS leading to motivated action
casey et al 2016 imbalance - PFC
top down modulation of subcortical outputs
cog control and goal orientation - modulate frontolimbic circuits via mPFC
casey et al 2016 imbalance in adolescence
lack of maturity across all regions into adulthod
sensorimotor and subcortical regions more connections than PFC
cortical thickness in sensorimotor cortices increase in late childhood then PFC increase in early adulthood (gogtay et al 2004)
gardner and steinberg 2005 peers on risk
peeers affect risk in driving
13-16y/o sig increase driving risk in presence of peers than alone than adults
peers prime heightened motivational states, diminish ability to perform cog self control
albert chien and steinberg 2013 risk and peers
risk beh in teens in presence of others
early adolescence x2 more likely to be risky in diving in presence of x2 same aged peers
late adolsecents 50% riskier
and more risk to immediate reward
silva et al 2016 risk and peers
presence of people or specific peers
18-22 or 15-30 sit in during driving in stoplight stimulation
- reach end of track as fast as possible - if stop lose time but if run could risk crash
peers sig increase than alone and sig more than adults
adults mean teen behave similar to when alone
