Inducing food craving through multisensory food exposure

Experiencing food craving is nearly ubiquitous and has several negative pathological impacts, but the basic neurocomputational mechanism of food craving remains poorly understood. Food cue-reactivity tasks are often used to study food craving but most paradigms ignore individual food preferences, which could confound the findings. We explored the neurocomputational mechanism of food craving using psychophysical tasks on human subjects considering their individual food preferences in a multisensory food exposure set-up. Participants were grouped into Positive Control (PC), Negative Control (NC), and Neutral Control (NEC) based on their preference for sweet and savory items. In Experiment 1, 68 adults reported their momentary craving of the displayed food stimuli through desire scale and bidding scale (willingness to pay) pre and post multisensory exposure. Participants were exposed to food items they liked (PC), disliked (NC) or were neutral to (NEC). Change-point detection analysis asserted the effect of the multisensory food exposure showing statistically significant increase in food craving for negative control post-exposure to disliked food items. A spline regression model confirmed a significant effect of desire rating on bidding behavior for the exposed food items for all subjects. In Experiment 2, 31 subjects participated in an EEG study under similar setup. We investigated Early Posterior Negativity (EPN) around 200 ms and Late Positive Potentials (LPP) in 300-600 ms for pre and post-exposure conditions. Post-exposure EPN was significantly larger than pre-exposure (t (11) = 2.3074, p= 0.0207) for NC. However, no significant change in LPP was observed between preexposure and postexposure for any of the controls. Our results demonstrate that multisensory food exposure can induce food craving even for disliked food items and EPN plays a role in modulating the craving. We further show that desire for exposed food items is correlated with willingness to pay irrespective of individual food preferences.