THE NEURAL REPRESENTATION OF ORAL TEXTURE INCLUDING FAT TEXTURE

Abstract

ABSTRACTThe brain areas that represent taste also provide a representation of oral texture. Fat texture is represented by neurons independently of viscosity: some neurons respond to fat independently of viscosity, and other neurons encode viscosity. The neurons that respond to fat also respond to silicone and paraffin oil, indicating that the sensing is texture‐ not chemo‐specific. This fat sensing is not related to free fatty acids such as linoleic acid; a few other neurons with responses to free fatty acids typically do not respond to fat in the mouth. Fat texture‐sensitive neurons are found in the primary taste cortex, the secondary taste cortex in the orbitofrontal cortex where the pleasantness of food is represented, and in the amygdala. Different neurons respond to different combinations of texture, taste, oral temperature, and in the orbitofrontal cortex to olfactory and visual properties of food. Complementary human functional neuroimaging studies are described.PRACTICAL APPLICATIONSThis research has implications for understanding how fat in the mouth is sensed. It therefore has implications for the design of foods that may mimic the mouthfeel of fat, but not its energy content.