Hunger selectively modulates corticolimbic activation to food stimuli in humans

Functional magnetic resonance imaging (fMRI) was used to determine whether visual responses to food in the human amygdala and related corticolimbic st ructures would be selectively altered by changes in states of hunger. Parti cipants viewed images of motivationally relevant (food) and motivationally irrelevant (tool) objects while undergoing fMRI in alternately hungry and s atiated conditions. Food-related visual stimuli elicited greater responses in the amygdala, parahippocampal gyrus, and anterior fusiform gyrus when pa rticipants were in a hungry state relative to a satiated state. The state-d ependent activation of these brain structures did not generalize to the mot ivationally irrelevant objects. These results support the hypothesis that t he amygdala and associated inferotemporal regions are involved in the integ ration of subjective interoceptive states with relevant sensory cues proces sed along the ventral visual stream.