Neural Correlates of Appetite and Hunger-Related Evaluative Judgments

Abstract

How much we desire a meal depends on both the constituent foods and how hungry we are, though not every meal becomes more desirable with increasing hunger. The brain therefore needs to be able to integrate hunger and meal properties to compute the correct incentive value of a meal. The present study investigated the functional role of the amygdala and the orbitofrontal cortex in mediating hunger and dish attractiveness. Furthermore, it explored neural responses to dish descriptions particularly susceptible to value-increase following fasting. We instructed participants to rate how much they wanted food menu items while they were either hungry or sated, and compared the rating differences in these states. Our results point to the representation of food value in the amygdala, and to an integration of attractiveness with hunger level in the orbitofrontal cortex. Dishes particularly desirable during hunger activated the thalamus and the insula. Our results specify the functions of evaluative structures in the context of food attractiveness, and point to a complex neural representation of dish qualities which contribute to state-dependent value.

Sex differences in cerebral responses to images of high versus low-calorie food

“…Albeit at a lower statistical threshold, women showed significantly greater activation within the insula to the high-calorie foods, whereas men showed significantly greater activation of the amygdala in response to the same stimuli. Because the insula has been implicated in feelings of hunger, visceral sensations, and evaluation of current need states [12,23], this finding raises the possibility that women may perceive food as a particularly salient stimulus that activates a spectrum of somatic sensations and associated cognitions. Men, in contrast, activated the amygdala, a more primal limbic structure involved in detecting biologically relevant stimuli and determining the appetitive value or attractiveness of food [12].…”

“…Based on prior evidence that women tend to express greater food-related concerns [10,11] and higher prevalence rates for eating disorders [8,9], it was hypothesized that females would show greater overall activation in response to high-calorie food images, particularly within prefrontal inhibitory and self-monitoring regions compared to males. Furthermore, given the importance of the insula in hunger and visceral sensations [12] and the amygdala in food-related processing [1,2,5,12], it was hypothesized that women would show greater activation than men within these specific regions.…”

The first taste is always with the eyes: A meta-analysis on the neural correlates of processing visual food cues

“…This has previously been explained by arguing that passively viewing pictures may not be rewarding enough to elicit a striatal response, i.e., for striatal activation actual reward receipt or anticipation to a real impending reward is required (Piech et al, 2009). However, the results of this meta-analysis suggest that the mere sight of food can elicit a striatal response, albeit only in response to high (versus low) energy foods.…”

Consumption of caloric and non-caloric versions of a soft drink differentially affects brain activation during tasting

“…Furthermore, animal work suggests that the response of certain taste neurons in the amygdala is inhibited when the taste stimulus is selfadministered, but not when delivery is imposed by an experimenter (Fontanini et al, 2009), as was the case in our study. While on the one hand the amygdala has been reported to encode the significance of (food) stimuli (Arana et al, 2003;LaBar et al, 2001;Pelchat et al, 2004;Piech et al, 2009), on the other hand it has been shown to encode stimulus intensity but not valence for odor (Anderson et al, 2003;Royet et al, 2003) and taste (Small et al, 2003a) stimuli. Our finding that the amygdala deactivates in response to an energycontaining drink while it activates in response to a non-caloric drink warrants further research.…”