Interactions between metabolic, reward and cognitive processes in appetite control
Traditional models of appetite control have emphasised the role of independent homeostatic (metabolic) and reward systems. More recently, this distinction has been abandoned in favour of a framework that emphasises the cross-talk between the neurochemical substrates of the two systems. In addition, evidence has emerged, that 1) cognitive processes such as learning, memory and attention play an important role in everyday appetite control and that 2) metabolic signals play a role in cognition. In this presentation I will present a model of appetite control that integrates cognitive, metabolic and reward mechanisms. The focus will be on studies that have examined the effects of satiation on fMRI BOLD activity in the human brain and the effects of metabolic signals on eating behaviours and cognition in healthy human volunteers. It will be argued that cognitive processes such as attention and memory underpin everyday eating behaviours and that metabolic signals affect eating behaviours, at least in part, via modulation of such higher cognitive functions.