Higher visceral adipose tissue is associated with decreased memory suppression ability on food-related thoughts: A 1-year prospective ERP study

Memory about food and eating is crucial in regulating appetite and eating behaviors. Successfully stopping vivid imagination of delicious food could help reduce food craving and thus reduce the possibility of further intake. Memory inhibition is a cognitive process that involves intentional suppression of certain memories coming to consciousness. Successful memory suppression derives from inhibitory control. Although considerable work has consistently observed the impairment in motor or response inhibitory control among individuals with obesity, there has been a lack of investigation into the influence of bodyweight status on memory inhibitory control. To fill this gap, current study investigated behavioral and neurophysiological correlates of memory suppression in young women. Using Think/No-Think task and event-related potentials among 47 females, we found that participants with higher visceral adipose tissue (VAT) showed a tendency towards decreased suppression ability for memories related to food but not memories related to nonfood items. In depth analysis showed that decrease in the differences in P2 amplitudes between suppression vs. retrieval of food-related memories mediated the impairment of suppression ability by high VAT. We then tested whether individual differences in memory suppression ability as well as ERP correlates predicted future BMI or VAT change over 1-year follow-up. Results showed that P2 amplitudes when retrieving food-related memory could predict VAT change at 1-year follow-up among participants with healthy BMI. These observations suggest a hypersensitivity inference hypothesis underlying memory control impairments. To be specific, deficits in memory suppression may be in part resulted from elevated sensitivity to the cues coupling with food-related memory. It extends previous studies of memory suppression with food rewards and provides the first evidence to help understand the relationship between inhibitory control on food-related memory and obesity.