title: 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.
authors.affiliation: School of Psychological Sciences, Monash University, 3800 Wellington Rd, Melbourne (Australia); Department of Clinical Psychology & Institute of Neuroscience F. Oloriz, Universidad de Granada, Universidad de Granada. Campus de Cartuja S/N, 18071 Granada, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Verdejo-García
authors.forename: Juan
authors.initials: J
authors.lastname: Verdejo-Román
authors.forename: Jacqueline S
authors.initials: JS
authors.lastname: Rio-Valle
authors.forename: Juan A
authors.initials: JA
authors.lastname: Lacomba
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Lagos
authors.forename: Carles
authors.initials: C
authors.lastname: Soriano-Mas
mesh_terms: D000293:Adolescent; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D001931:Brain Mapping; D002648:Child; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D019964:Mood Disorders / Q000209:etiology*; D009765:Obesity / Q000150:complications / Q000473:pathology / Q000523:psychology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D012201:Reward; D012720:Severity of Illness Index; D012919:Social Behavior; D013223:Statistics as Topic
chemical_list: D010100:Oxygen
keywords: anterior insula; fMRI; obesity; social decision making