Food images engage subliminal motivation to seek food.

Abstract

Human eating behaviour is motivated and shaped by a complex interaction of internal drives such as hunger, external influences such as environmental cues and the sensory properties of food itself. Thus, as is demonstrated by the example of sensory-specific satiety (SSS), hunger may be reduced but particular foods (for example, desserts) retain their attraction and their ability to prompt consumption. In considering consumption, and overconsumption, it is therefore important to understand the interaction between internal and external drives to eat. Using grip force as a measure of motivation, we examined this interaction using an SSS manipulation. Critically, we sought to determine whether food stimuli would exert their influence even when they were subliminally presented (and thus not accessible to consciousness), and whether this unconscious influence would be flexibly updated in response to changes in food reward value with satiety. Demonstrating that the SSS effect remains when external stimuli are not consciously perceived, our data highlight the importance of even the most subtle, fleeting and even subliminal external events in shaping our motivation towards food.