Adolescent Brain Development:Part 2

Cheryl Sisk, PhDMichigan State University

14-25 yr olds account for most arrests and homicides

FBI and Bureau of Justice Statistics

Talk Outline• Neural circuits governing behavioral

control, social cognition, emotion, and reward

• Behavioral and neural reactions to reward

• Behavioral and neural reactions to threat• Risk taking and influence of peers• Implications for policy

Overview of brain circuitry• Prefrontal cortex

(PFC), anterior cingulate cortex (ACC): executive function/behavioral control/decision making

• Ventral striatum (VS): reward and motivation

• Amygdala (AMY): emotion processing and fear assessmentTost and Meyer-Lindenberg (2012)

Nature Medicine 18:211-13

Kirk

Spock

Adolescents rate sucrose more positively than adults

Galvan and McGlennan (2013). J Cognitive Neuroscience 25:284-296

Adolescents: 13-17 yrsAdults: 23-25 yrs

Ventral striatum is more activated by sucrose in adolescents than in adults

Galvan and McGlennan (2013). J Cognitive Neuroscience 25:284-296

Go-Nogo task to assess reactivity

Adolescents show greater behavioral reactivity and greater activation in reward areas to happy faces

Casey (2015). Beyond simple models of self-control to circuit-based accounts of adolescent behavior. Annual Rev Psychology 66:6.1-6.25

Children: 6-12Teens: 13-17Adults: 18-27

Adolescents show greater behavioral reactivity to fearful faces

Children: 6-12Teens: 13-17Adults: 18-27

Dreyfuss et al (2014). Teens impulsively react rather than retreat from threat. Dev Neurosci 36:220-27

Cohen and Casey (2014). Rewiring juvenile justice: the intersection of developmental neuroscience and legal policy. Trends in Cog Sci 18: 63-65

Hare et al (2008). Biological substrates of emotional reactivity and regulation in adolescence during an emotional go-nogo task. Biol Psychiat 63:927-34

Adolescents show greater amygdala activation in response to fearful faces

Children: 7-12Teens: 13-18Adults: 19-35

Stoplight task to assess risk taking

Presence of peers increases risk taking

Chein et al (2011). Peers increase adolescent risk taking by enhancing activity in the brain’s reward circuitry. Devel Sci 14:F1-10.

Peers increase activity in ventral striatum

Chein et al (2011). Peers increase adolescent risk taking by enhancing activity in the brain’s reward circuitry. Devel Sci 14:F1-10.

Summary

• Adolescents display heightened attention and reactivity to reward and threat

• Adolescents display greater reliance on limbic emotional regions than on prefrontal control regions

• Peer influence exacerbates risk taking by adolescents

Imbalance Model of the Adolescent Brain

Casey (2015). Beyond simple models of self-control to circuit-based accounts of adolescent behavior. Annual Rev Psychology 66:6.1-6.25

What neuroscience does and does not tell us about adolescent culpability or

rehabilitation

• Does not imply that juveniles should not be accountable

• Cannot be used to assess maturity level of an individual

• Diminished responsibility should be considered in determination of punishment

• Correctional environment can influence developmental trajectory

• Opportunities for developing prosocial behaviors and emotional regulation will assist “maturing out”