Cortical systems involved in appetite and food consumption
Food intake is essential to sustain life, and the sensory systems of taste and smell are among the most fundamental building blocks of the brain's natural reward systems. Human food intake relies on a complex hierarchy of cortical processing that includes obtaining stable sensory information, evaluation for desirability, and choosing the appropriate behavior. Food intake and the control of appetite rely on cortical processing in humans and other primates to a much larger degree than other mammals. This chapter describes the evidence from neurophysiology, neuropsychology, and neuroimaging. It proposes four main computational principles: motivation-independent processing of identity and intensity; formation of learning-dependent multimodal sensory representations; reward representations using mechanisms including selective satiation; and representations of hedonic experience, monitoring/learning. This chapter also proposes a model incorporating these computational principles for the orbitofrontal cortex, which is one of the most important nodes linking sensory and hedonic systems involved in appetite and food consumption in the human brain. This is a simplified model, but it addresses the basic principles of how food consumption and appetite are controlled in the human brain. © 2007 Elsevier Inc. All rights reserved.