Adolescent brain Flashcards
Galvan et al. (2007) tested children (7-11 y/o), adolescents (13-17 y/o) and adults (23-29 y/o) and the number of of risk-taking behaviours they performed.
What did pps have to do for the researchers to assess their level of risk taking?
There were 34 items that pps had to give 3 ratings each for…
a) likelihood of engaging in this activity in the next 6 months
b) likelihood of a negative consequence
c) likelihood of a positive consequence
Pps were asked how likely they were to engage in… (in the next 6 months)
- risky sexual behaviour
- heavy drinking
- drug use
- aggressive & illegal behaviours
- irresponsible academic/work behaviours
- high-risk sports
In Galvan et al.’s (2007) study, pps had a fMRI scan while they did a delayed response task.
What did this task involve?
3 pirate pictures (cues) were associated with a (initially unknown) reward (low/high)
- a cue appeared and, after a delay, pps had to indicate which side of the screen that the cue had appeared
- after another delay, the amount of reward associated with that cue was displayed
How did Galvan et al. (2007) ensure that this was an implicit learning task?
They asked pps which pictures (cues) matched with which reward
–> pps couldn’t say, which implies that it is an implicit learning task
What did Galvan et al. (2007) find in their study?
A change in signal in the NAcc was positively associated with children, adolescent and adult self-ratings of the likelihood to engage in risky behaviours, but negatively associated with their self-assessed likelihood of negative consequences for these actions
What was a bigger signal in the NAcc related to reward linked to in Galvan et al.’s (2007) study?
A bigger signal in the NAcc related to reward was linked to riskier behaviour
2 adolescents in Galvan et al.’s (2007) study had the biggest risk-taking scores and NAcc responses.
What does this suggest?
This suggests that some adolescents have a bigger response to risk-taking and reward than adults & children
Galvan et al. (2007) found an association between pps response to the reward and risky behaviour.
What was the association?
The bigger their response (to the reward), the more likely they were to display risky behaviours
Who proposed the Triadic Brain model?
Ernst, Pine and Hardin (2006)
What is the Triadic Brain model?
A model of which brain areas respond to reward and risk
What is the basis of the Triadic Brain model?
The brain works as a system
- may parts are incorporated into the assessment of risk and reward
- to decide whether something is rewarding/risky we compare it to our past experiences
3 areas of the brain are important in our assessment of risk and reward.
What are these 3 areas?
- amygdala
- ventral striatum
- PFC
According to the Triadic Brain model, what is the amygdala involved in?
- when the amygdala is active, we feel fearful (something threatening is happening in the environment) → increases our response to risk
- when the amygdala isn’t active, no fear learning is happening and we feel calm and secure
- amygdala assesses FEAR vs. SAFETY
According to the Triadic Brain model, what is the ventral striatum involved in?
- when the VS is active, we are experiencing something rewarding
- when the VS isn’t active, nothing rewarding is happening in the environment and we feel boredom
According to the Triadic Brain model, what is the PFC involved in?
- assesses the signal to ensure an appropriate response is made to the context
- makes a cognitive assessment of our emotional response
- regulates the response in our amygdala and VS
When the amygdala and VS are firing highly, what are we doing?
We are performing a risky + rewarding behaviour
In relation to risk and reward, how does the brain develop with age?
- greater reactivity of reward centres
- decreased reactivity of threat centres
- less regulation
At which age are we most sensitive to reward and least sensitive to threat?
Adolescence
If we are sensitive to reward and not sensitive to threat, what are we more likely to do?
We are more likely to take risks
Connections from the PFC are weaker/stronger during adolescence.
Connections from the PFC are WEAKER during adolescence.
What is the result of weaker connections from the PFC in adolescence?
It means we are less able to regulate our behaviour → more likely to respond to things emotionally, rather than assess them cognitively
–> suggests decreased inhibition during adolescence, especially to rewarding stimuli
Why is the Triadic Brain model incorrect?
Adolescents also have increased responses to threat (amygdala), not just to rewards (VS) → the amygdala should be just as big as the VS on the diagram
Somerville et al. (2011) did a Go-No-Go task with happy faces and neutral faces.
What did this study involve?
Somerville et al. (2011):
Pps had to press a key when a neutral face appeared on a screen but NOT when a happy face appeared
Happy faces = social rewards
What did Somerville et al.’s (2011) study test?
Somerville et al.’s (2011) study tested pps’ ability to inhibit their prepotent response (key press to a happy face, i.e. social reward)
What did Somerville et al. (2011) find in their study?
There was no difference in the number of correct responses in children, adolescents or adults BUT adolescents were more likely to respond to no-go stimuli (happy faces)
- adolescents were less able to inhibit their response to a positive social reward
- this is associated with increased activity in the VS
Does Somerville et al.’s (2011) study support or disprove the Triadic Brain model?
Somerville et al.’s (2011) findings provide partial support for the Triadic Brain model
Who proposed an alternative model to the Triadic Brain model?
Casey et al. (2008)
What is the basis of Casey et al.’s (2008) model?
- different areas of the brain develop at different times
- the PFC develops linearly with age
- the VS develops faster and less linearly with age (peaks, then flattens in adulthood)
How does the linearly development of the PFC influence our cognition/behaviour?
The PFC develops linearly with age - this increases our ability to control things cognitively
Measuring ________ compounds risk and reward (because _______ involves risk and reward).
Measuring IMPULSIVITY compounds risk and reward (because IMPULSIVITY involves risk and reward).
Is Casey et al.’s (2008) correct?
Casey et al.’s (2008) model can’t be correct - it only takes reward into account and ignores risk
Who did a similar study as Somerville et al. (2008), but using fearful faces (= social threat) instead of happy faces?
Casey et al. (2008)
What did Casey et al.’s (2008) Go-No-Go study involve?
They used the same Go-No-Go paradigm as Somerville et al. but replaced happy faces (= social reward) with fearful faces (= social threat)
What did Casey et al.’s (2008) Go-No-Go study find?
They found the same pattern of increased false alarms in adolescents
- adolescents had an increased impulse to respond in threatening situations
→ suggests that previous models are too simple
Experience drives the connections between areas. This means that there will be stronger connections between controlling parts of the ___ than reactive parts of the ___.
Experience drives the connections between areas. This means that there will be stronger connections between controlling parts of the PFC than reactive parts of the VS.
Which researcher/s did a study investigating the effect of low-risk and high-risk gambles on brain activity?
van Leijenhorst et al. (2010)
What were van Leijenhorst et al. (2010) looking for?
They were looking for an inverted-U shaped response to reward and a linear response to cognitive control with age
Which model were van Leijenhorst et al. (2010) trying to test - the Triadic Brain model or Casey et al.’s (2008) model?
van Leijenhorst et al. (2010) were testing Casey et al.’s (2008) model
Which age groups did van Leijenhorst et al. (2010) use in their study?
8-10 y/o
12-14 y/o
16-17 y/o
19-26 y/o
What did pps have to do in van Leijenhorst et al.’s (2010) study?
Pps chose a low-risk OR high-risk gamble that was associated with a monetary reward (presented visually by the number of cake wedges)
- they would win if the colour of the wedge chosen by the computer matched the colour of the wedge they chose
What were the chances of winning and associated monetary rewards for low-risk gambles and high-risk gambles in van Leijenhorst et al.’s (2010) study?
Low-risk: 66% chance of winning, always won 1 euro
High-risk: 33% chance of winning; the amount they won varied across trials (2, 4, 6, 8 euros)
What did van Leijenhorst et al. (2010) find?
Across all ages (8-10, 12-14, 16-17, 19-26), the proportion of high-risk gambles increased as the size of the potential reward increased
- they concluded that adolescents are not more reactive to rewards than younger/older
Which areas of their brains were active when gambles led to winning in van Leijenhorst et al.’s (2010) study?
The mPFC and VS were active when gambles led to winning
van Leijenhorst et al. (2010) found a correlation between activity in the _____ and the size of _____, but not when pps took high-risk gambles (only when they took low-risk gambles).
van Leijenhorst et al. (2010) found a correlation between activity in the VS and the size of REWARD pps received, but not when pps took high-risk gambles (only when they took low-risk gambles).
At which age did pps show greatest activity in response to gain in the VS in van Leijenhorst et al.’s (2010) study?
Adolescents showed greatest activity in response to gain in the VS
Which area of the brain was most reactive to reward in adolescents (showed a non-linear response) in van Leijenhorst et al.’s (2010) study?
The caudate (= part of the VS) was most reactive to reward in adolescents (showed a non-linear response)
Older pps chose less/more high-risk gambles than younger pps when potential rewards were lower.
Older pps chose LESS high-risk gambles than younger pps when potential rewards were lower.
Why did older pps choose less high-risk gambles than younger pps when potential rewards were lower?
They had developed more expertise
- younger haven’t learnt yet
- as you get older, you get better at assessing what the risk is for getting a reward (risk-reward trade-off)
What type of response to received reward does van Leijenhorst et al.’s (2010) study confirm?
van Leijenhorst et al.’s (2010) study confirms an inverted-U shaped response to received reward
van Leijenhorst et al.’s (2010) study confirms a peak/reduction in activity in reward centres in adolescence.
van Leijenhorst et al.’s (2010) study confirms a PEAK in activity in reward centres in adolescence.
What is the Fuzzy Trace theory?
To be good at something, we must have expertise
- adults have more expertise than adolescents/children
- adults have gained the most expertise to choose the best outcome
In relation to expertise, why do adolescents take more risks?
Adolescents are still learning so they take more risks until they learn the relationship between risk and reward better
Risky choices are associated with activity in which area of the brain?
vmPFC
- if there is more reward reactivity, you take more risks
In which area of the brain is the high-risk response greater than the low-risk response?
mPFC
- we are are more likely to take a high-risk decision rather than a low-risk decision when mPFC is activated
In which area of the brain is the low-risk response greater than the high-risk response?
dlPFC
- we are are more likely to take a low-risk decision rather than a high-risk decision when the dlPFC is activated
Why are we more likely to take a low-risk decision if the dlPFC is activated?
- this area is associated with cognitive control
- if the dlPFC is activated, we have more cognitive control
If we inhibit the reward response, we prevent ourselves from…
…doing a behaviour that has been previously rewarded
What does the ACC do?
- assesses social and physical pain
- registers cognitive/emotional error (anything different to what you predicted)
As you get older, what happens to the ACC response?
As you get older, the ACC responses decreases (linearly)
- this is related to cognitive control
- supports increases in cognitive control with age
Activity in the _______ _____ (associated with emotional responses) is associated with age.
Activity in the SUBCALLOSAL CORTEX (associated with emotional responses) is associated with age.
When do we have more activity in the subcallosal cortex - when we are in low-risk situations or high-risk situations in adolescence?
There is more activity in the subcallosal cortex when we are in high-risk situations in adolescence
- non-linear
- peak in adolescence
Non-linear changes in brain activity (with age) is associated with _______ parts of the brain.
Non-linear changes in brain activity (with age) is associated with EMOTIONAL parts of the brain.
Linear changes in brain activity (with age) is associated with _______ parts of the brain.
Linear changes in brain activity (with age) is associated with COGNITIVE parts of the brain.
What is an adolescent-specific effect?
An effect that only peaks in adolescence
What is an adolescent-emergent effect?
An effect that increases linearly through adolescence and plateaus in adulthood
Which area/s of the brain respond to adolescent-specific effects?
There is a big emotional response in limbic structures
Which area/s of the brain respond to adolescent-emergent effects?
There is activity in areas associated with cognitive control…
- ACC
- premotor cortex
Which researcher/s did a study investigating which areas of the brain were activating for adolescent-specific and adolescent-emergent effects?
Dreyfuss et al. (2014)
Which areas did Dreyfuss et al. (2014) find were activated for adolescent-specific effects?
- left orbitofrontal cortex
- lmPFC
- left striatum
Which areas did Dreyfuss et al. (2014) find were activated for adolescent-emergent effects?
- left premotor cortex
- right inferior frontal gyrus (IFG)
- right ACC
According to Dreyfuss et al. (2014), adolescent-specific effects require less/more emotional regulation for emotional stimuli than adolescent-emergent effects.
According to Dreyfuss et al. (2014), adolescent-specific effects require MORE emotional regulation for emotional stimuli than adolescent-emergent effects
Why do adolescent-specific effects require less/more emotional regulation for emotional stimuli than adolescent-emergent effects?
Heightened sensitivity to emotional stimuli (not found with neutral stimuli)
–> this might cause adolescents to react rather than retreat from potential threats
Which area/s of the brain do hormonal changes affect?
Hormonal changes affect limbic structures that are sensitive to hormonal changes
Continued development of the PFC and connections between the PFC and subcortical areas with age leads to…
…reduced ability to exert cognitive control, especially when emotion is heightened
What do adolescent-emergent effects involve, in relation to conflict?
Adolescent-emergent effects involve detection and resolution of conflict
- the ability to ignore irrelevant info
- shows an increase in cognitive control
What gender effect did Dreyfuss et al. (2014) find in their study?
For males…
- adolescent males made more incorrect responses to threatening faces than male children/adults
- the pattern of behaviour for males was matched by activation of the left orbitofrontal cortex (= active in approach-related behaviours)
Activation of the left OFC was matched to males’ behaviour in Dreyfuss et al.’s (2014) study - what does this suggest?
The left OFC is active in approach-related behaviours
–> suggests that males choose to approach fearful faces (rather than avoid/retreat from)
What gender effect did Dreyfuss et al. (2014) find in their study?
For females…
- females showed no age differences
- female adolescents didn’t respond more to threatening faces than female children/adults did
- there was a peak in activation in the lmPFC (= associated with avoidance behaviours)
Activation of the lmPFC was matched to females’ behaviour in Dreyfuss et al.’s (2014) study - what does this suggest?
The lmPFC is associated with avoidance behaviours
–> suggests that females are more likely to avoid situations involving fearful faces (rather than approach)
Who proposed the Imbalance Framework?
Casey et al. (2015)
What perspective does the Imbalance Framework take?
It is an integrated circuit-based perspective rather than an orthogonal system (like the Dual Systems theory)
What does the Imbalance Framework propose?
Changes in self-control in adolescence coincide with developmental cascades in regional fine-tuning of connections with subcortical and cortical prefrontal and limbic circuits
Galvan et al. (2006) used a reward paradigm with children, adolescents and adults.
What did they find/show?
Galvan et al. (2006) showed an adolescent-specific sensitivity to reward outcome in subcortical regions (compared to orbital frontal regions)
According to the Imbalance Framework, what is the cause of the shift in cognitive capacity from childhood to adulthood?
The shift in cognitive capacity from childhood to adulthood is the result of a fine-tuning of circuits from subcortico-subcortical to cortico-subcortico to cortico-cortico
According to the Imbalance Framework, the processing of emotional stimuli and exertion of cognitive control relies on…
…inputs from subcortical circuitry involving the amygdala and VS
The Imbalance Framework emphasises shifts in the flow of info through…
…brain structures that are continually being refined with experience and maturation
According to the Imbalance Framework, which structures do we concentrate on in adolescence?
In adolescence, we concentrate on cortical structures
According to the Imbalance Framework, which structures is there less connectivity to in adolescence?
In adolescence, there is less connectivity in cortical structures
According to the Imbalance Framework, eventually ______ structures become the prominent connections.
Eventually CORTICAL structures become the prominent connections.
According to the Imbalance Framework, what is the result of cortical structures becoming the prominent connections?
We become less response to our immediate emotions
Which researcher/s investigated pps perceptibility to risk when in the presence of a peer during a driving test?
Albert et al. (2013)
What did Albert et al. (2013) do and find in their driving test study?
Pps did a driving test - they had to reach the end of the track as fast as possible)
They were tested alone OR tested whilst being observed by a peer
–> pps made more risky decisions when a peer was present
The findings from Albert et al.’s (2013) study correlate with activity in which area/s of the brain?
Pps made more risky decisions when a peer was present - this correlated with more activity in the VS
Less inhibitory control in adolescence leads to…
…decreased inhibition of their prepotent response
Silva et al. (2016) had pps perform an activity either…
a) solo
b) with a peer group
c) with a peer group + a slightly older adult
What did they find?
The effect of the peer group was mitigated by the presence of the older adult
- pps took more risks when with their peers
- pps took the same amount of risks alone as they did when they were with their peers + older adults (i.e. low amount)
