Weight-Related Differences in Salience, Default Mode, and Executive Function Network Connectivity in Adolescents.

Objective: The current study examined whether adolescents with weight status ranging from lean to obesity showed weight-related differences in the default mode network (DMN), the executive function network (EFN), and the salience network (SN).

Methods: One hundred sixty-four adolescents participated in a resting-state functional connectivity scan. A general linear model was used to examine differences in scan patterns among adolescents with lean weight, overweight, and obesity.

Results: Adolescents with obesity compared with those with lean weight showed stronger within-SN connectivity among the medial orbitofrontal cortex, olfactory tubercle, and pallidum; however, they showed lower connectivity between the amygdala and SN regions (nucleus accumbens, thalamus, putamen). Those with obesity also showed lower connectivity between SN (amygdala, caudate) and DMN (parahippocampus, hippocampus, precuneus) regions. Adolescents with obesity compared with those with lean weight showed lower connectivity between SN (medial orbitofrontal cortex) and EFN (ventrolateral prefrontal cortex) regions.

Conclusions: Obesity appears to be related to stronger connectivity within and between regions implicated in determining the salience of stimuli, which may have implications for reward processing. Lower connectivity between SN and EFN regions may suggest that executive-control efforts are going "off-line" when salience and reward-processing regions are engaged in adolescents who have obesity.