Dysfunctional involvement of emotion and reward brain regions on social decision making in excess weight adolescents

Abstract

Obese adolescents suffer negative social experiences, but no studies have examined whether obesity is associated with dysfunction of the social brain or whether social brain abnormalities relate to disadvantageous traits and social decisions. We aimed at mapping functional activation differences in the brain circuitry of social decision making in adolescents with excess versus normal weight, and at examining whether these separate patterns correlate with reward/punishment sensitivity, disordered eating features, and behavioral decisions. In this fMRI study, 80 adolescents aged 12 to 18 years old were classified in two groups based on age adjusted body mass index (BMI) percentiles: normal weight (n = 44, BMI percentiles 5th-84th) and excess weight (n = 36, BMI percentile ≥ 85th). Participants were scanned while performing a social decision-making task (ultimatum game) in which they chose to "accept" or "reject" offers to split monetary stakes made by another peer. Offers varied in fairness (Fair vs. Unfair) but in all cases "accepting" meant both players win the money, whereas "rejecting" meant both lose it. We showed that adolescents with excess weight compared to controls display significantly decreased activation of anterior insula, anterior cingulate, and midbrain during decisions about Unfair versus Fair offers. Moreover, excess weight subjects show lower sensitivity to reward and more maturity fears, which correlate with insula activation. Indeed, blunted insula activation accounted for the relationship between maturity fears and acceptance of unfair offers. Excess weight adolescents have diminished activation of brain regions essential for affective tracking of social decision making, which accounts for the association between maturity fears and social decisions.

Social Stress Increases Cortisol and Hampers Attention in Adolescents with Excess Weight

“…In favor of the first notion, neuroimaging studies have shown that the impact of social evaluation on decision-making is mediated by increased activation of ventral striatal and orbitofrontal regions [ 43 ], which are generally sensitized during adolescence. In favor of the second notion, we have observed that excess weight and normal weight adolescents recruit different brain circuitries during the pondering of social decisions [ 44 ]. Future studies are warranted to address this question.…”

Brain substrates of social decision‐making in dual diagnosis: cocaine dependence and personality disorders

“…We administered a validated ‘single‐shot’ (or non‐iterative) version of the UG (Crockett et al ; Verdejo‐Garcia et al ). The task involved one proposer and one responder, and participants always played the responder's role (see also Procedures section in the succeeding texts).…”

“…Participants were scheduled 60 minutes before the scanning to be briefed about the UG; this briefing was conducted by a graduated psychologist following previously validated instructions (Crockett et al ; Verdejo‐Garcia et al ). To enhance the credibility and the interpersonal appeal of the UG, participants were told that the proposer was another participant of the research project, who had left a picture of himself/herself and a list of proposals after his/her own scanning session.…”

Enhanced neural responsiveness to reward associated with obesity in the absence of food‐related stimuli

“…In a study by Kishinevsky et al [], executive function in the prefrontal cortex during a delay discounting trial could predict subsequent weight gain in obese subjects [Kishinevsky et al, ]. Moreover, Verdejo‐Garcia et al demonstrated associations between abnormal neural activation in reward brain regions and social decision‐making in obese adolescents [Verdejo‐García et al, ].…”