Deficits in food reward regulation of restrained eaters: a fMRI study based on memory inhibition

Subjects: Psychology >> Cognitive Psychology submitted time 2022-07-09

邹雨晴 梁蓉芳 敖华 高源 沈佳雯 高笑

Abstract：

[Objective] The current study used the Think/No-Think paradigm combined with fMRI techniques to explore the cognitive and brain mechanisms of food memory retrieval inhibition and its reward devaluation effects among restrained eaters.

[Methods] Forty participants (all female) aged between 18-24 were recruited for this study, 21 of whom were restrained eaters and 19 were unrestrained eaters. Participants completed a food version TNT task, which consisted of learning phase, TNT phase and test phase. The TNT phase was completed in a 3.0T Siemens Prisma MRI scanner. Before and after the whole three phases of TNT task, participants rated the subjective value of the food items in the pictures.

[Results] Behavioral results revealed no significant differences in memory retrieval inhibition effect between restrained eaters and unrestrained eaters. However, restrained eating scores were negatively correlated with the effect of reward devaluation of inhibited food items. Neuroimaging data showed that restrained eaters had greater activation of dorsolateral prefrontal cortex (dlPFC) and lower activation of reward and memory areas than unrestrained eaters during inhibiting food-related memories. In addition, PPI analysis showed that the connectivity strength of dlPFC with hippocampus, parahippocampus, thalamus and posterior cingulate cortex were negatively corrected with restrained eating scores. Further analysis showed that connectivity strength between dlPFC and thalamic mediated the negative association between restrained eating scores and the reward devaluation effects of memory inhibition.

[Limitations] The subjects in this study were all healthy university students whose performance in executive functioning was at its peak, therefore a ceiling effect may have occurred.

[Conclusion]The current observations support the goal conflict model from the perspective of memory retrieval inhibition, whereby restrained eater has difficulty in successfully regulating conflict between inhibition and food reward by devaluation food reward. This kind of deficiency in reward devaluation due to deficits in memory inhibition may further increase the risk of uncontrolled food intake in food-rich environments of restrained eaters.

Peer Review Status:Awaiting Review

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