Dissociable prefrontal and limbic brain networks represent distinct information about the healthiness and pleasantness of food

Abstract

Our knowledge of food often includes information about its origin (natural, manmade), nutritional content, and hedonic value, in addition to information about its sensory properties like taste, smell, and texture. These various sources of information are important for guiding our food choices and behaviors. Studies of the neural response to food stimuli have typically focused on the overall response to food vs. other object categories, an approach which overlooks the broad variation in properties present across different food types. In order to examine how information about food is represented at a finer-grained level, we analyzed the neuroimaging data of 64 healthy participants who viewed pictures of 36 types of food during functional MRI. We used a clustering approach based on Representational Similarity Analysis (RSA) that partitioned food-responsive brain regions into two sub-networks, based on their multivariate response to food pictures: a Prefrontal network composed of fronto-parietal brain regions, and a Limbic network composed of cortico-limbic and sub-cortical brain regions. We then performed RSA within these sub-networks using data from an online behavioral task which identified the most relevant properties underlying the similarity of those 36 foods. This analysis revealed that the Prefrontal sub-network, composed of regions involved in behavioral regulation, most strongly represented subjective estimates of how processed, artificial, and un-healthy those foods were. In contrast, the Limbic network, composed of regions associated with affect and reward, most strongly represented subjective ratings of food pleasantness, based on data collected during a separate imaging task. These results reveal that food-related information is distributed across distinct brain networks involved with representing the sensory and hedonic aspects of food and with the behavioral regulation of food consumption.