Week 7 - Adolescent brain

Dual-systems model

self-control results from a ‘cool’ and ‘hot’ system. Heuristically used to explain brain systems that underlie behavior involving immediate vs delayed rewards

Cool system (dual-systems model)

strategic and emotionally neutral, a flexible cognitive system. Prefrontal control system

Hot system (dual-systems model)

emotionally driven by fears, desires and reflexes. Motivational limbic system

Triadic model of motivated behavior

‘hot’ system is divided into two subsystems. Motivated behavior comes from a balance between these two subsystems, with adolescence being a time when there is a tilt or bias toward the reward-driven system. Proposed that this is driven by gonadal hormones

Reward system

located in the ventral striatum

avoidance system

located in the amygdala

Imbalance model

regional neurochemical, structural and functional brain changes within development lead to imbalances within brain circuitry that may explain nonlinear changes in behavior during adolescence

3 key brain areas involved with self-control

amygdala, prefrontal cortex, ventral striatum

Amygdala

associative learning and determination of emotional significance

Prefrontal cortex

implicated in reasoning and behavioral regulation

Ventral striatum

implicated in learning and predicting of rewarding outcomes

These brain regions were sensitive to cues that predicted the largest reward

Ventral striatum, orbitofrontal cortex

This brain region showed a linear change with age and was associated with overall accuracy on no-go trials regardless of social cue type

Ventrolateral prefrontal activity

This brain region mediates fear responses on the basis of whether the specific environment as been associated with safety or danger

Hippocampus

There is enhanced activity in this brain region to repeated presentation of empty threat

Amygdala

There is less connectivity in this region to repeated presentation of empty threat

fronto-amygdala circuit