Many experiences, like food, wine and sex, are pleasurable. These experiences are also desired, but less so when sated. The aim of this proposal is to understand how satiation regulates desire. We propose two memory-based models, and test them using several new experimental approaches. This is significant, not only because poorly regulated desire is linked to many social and economic ills (e.g., over-eating), but also because it is a key part of human motivation that is poorly understood. The expected outcome is a new theoretical model of how memory processes interact with bodily signals to generate both sated states and desire. The benefits include a new understanding of how desire is regulated and how and why this might break down.