Previous studies suggest obesity is associated with altered function within the insula and dorsomedial frontal cortex (including dorsal anterior cingulate cortex; DMFC/dACC), reflecting abnormal reward processing and reduced sensitivity to feelings of satiety. Given the proposed roles of DMFC/dACC in monitoring response conflict and reward-based decision making, the present study examined DMFC/dACC activation, and functional connectivity between the DMFC/dACC and the anterior insula (AI), during food-related decision-making. Twenty participants recruited from the general population (10 Female) performed a decision task while undergoing functional magnetic resonance imaging. They were instructed to "choose the healthier option" when simultaneously shown pairs of images of different foods. Significant DMFC/dACC activation was observed during food-related decision-making, and activation levels also positively correlated with self-reported cravings for high-fat foods (r = 0.57, p = 0.009) and self-reported desire to eat the high-fat foods depicted in the images (r = 0.48, p = 0.032). Negative functional connectivity estimates between the right AI and DMFC/dACC were also associated with self-reported control over eating (r = -0.50, p = 0.025). These results suggest that (1) more intense cravings for unhealthy foods are associated with greater response conflict when deciding between healthy and unhealthy food options, and (2) lack of eating-related control may involve a reduced influence of insula-mediated bodily signals on decision-making. This task may offer a neuroimaging-based probe for identifying individuals vulnerable to eating-related disorders and should be replicated in clinical populations.
Keywords: Decision-making; Dorsal anterior cingulate cortex; Dorsomedial frontal cortex; Food; Insula; Obesity.