A time of change: behavioral and neural correlates of adolescent sensitivity to appetitive and aversive environmental cues

In typically developing youth, emotional reactivity to negative content declines and regulatory capacity increases with age.

“Prevailing models of emotional development posit that emotional reactivity to negative content declines, while regulatory capacity increases with age in typically developing (TD) youth [18,19].”

Puberty/adolescence represents the second particularly sensitive and vulnerable period with a new major change in HPA axis activity.

“The later developmental stage of puberty/adolescence represents the second particularly sensitive and vulnerable period with a new major change in HPA axis activity.”

During adolescence, emotionality is heightened by neural changes while self-regulation remains underdeveloped.

“This is due in part, to the physical and chemical changes occurring in the brain from early adolescence, which result in a ‘neural mismatch’ whereby emotionality is heightened in response to real and/or perceived stressors (Bailen et al. 2019), yet the self-regulatory system required to manage these emotions remains largely underdeveloped until early adulthood (Somerville et al. 2010).”

In puberty/adolescence, the HPA axis transitions from hypo-responsivity into a period of increased activity with progressively higher basal and reactive cortisol levels.

“In this phase, the HPA axis transitions from hypo-responsivity into a period of increased activity (101, 114–116) with progressive higher basal (106, 110, 117, 118) and reactive (106, 118–121) cortisol levels.”

Triangulating dietary data with data from wearable tech, mobile apps, school canteen sales data, ecological momentary assessment, direct observation, and proxy reports can provide insights into behaviour changes.

“Triangulating this data with data from wearable tech, mobile apps, and school canteen sales data, ecological momentary assessment (EMA) for real-time data collection, direct observation of adolescents’ eating behaviours, and proxy reports from family members can provide insights into behaviour changes [70–76].”

Adolescence is characterized by unique patterns of neural activity and changes in innervation and myelination within brain regions that contribute to heightened incentive salience at this developmental stage.

“Adolescence is characterized by unique patterns of neural activity and changes in innervation and myelination within brain regions that contribute to heightened incentive salience at this developmental stage (Ernst et al., 2005, Ernst et al., 2006, Somerville et al., 2010).”

The imbalance model, unlike dual systems accounts, does not propose orthogonal systems, but rather attempts to account for adolescent behavior from an integrated circuit-based perspective.

“The imbalance model, unlike dual systems accounts of adolescence (Steinberg et al., 2008, Luna and Wright, in press) does not propose orthogonal systems, but rather attempts to account for adolescent behavior from an integrated circuit-based perspective (Casey et al., 2008, Somerville et al., 2010, Casey, 2015).”

Casey's integrative developmental theory postulates that increased emotionality in adolescence results from an imbalance between amygdala and prefrontal cortex development.

“Casey and colleagues88,89 provide an integrative developmental theory that postulates that the increased emotionality common during adolescence results from the imbalance between patterns of amygdala and PFC development (Fig. 3).”

The combination of heightened activity in reward-related circuits and underdeveloped cognitive control centres contributes to greater emotionality, impulsivity and reward-seeking behaviour.

“The combination of heightened activity in reward-related circuits and underdeveloped cognitive control centres contributes to greater emotionality, impulsivity and reward-seeking behaviour174,175.”

Dual system theories of adolescent neurodevelopment posit that risk taking increases during adolescence due to a competition between the affective reward sensitivity system and the cognitive control system.

“Dual system theories of adolescent neurodevelopment posit that risk taking increases during adolescence due to a competition between two neural systems — the affective system, which is involved in reward sensitivity, and the cognitive control system, which is involved in cognitive regulation (Somerville et al., 2010; Steinberg, 2010).”

Risk taking arises, in part, due to a cortical-subcortical imbalance, in which a relatively immature PFC is less effective at regulating a sensitive and more rapidly developing ventral striatum.

“These findings are consistent with the dual system model of neural development, which suggests that risk taking arises, in part, due to a cortical–subcortical imbalance, in which a relatively immature PFC is less effective at regulating a sensitive and more rapidly developing ventral striatum (Somerville et al., 2010; Steinberg, 2010).”