Neural responses to dynamic versus static food cues: A pilot functional MRI study

Contemporary food environments are dominated by dynamic food cues such as moving videos of food, which may engage neural pathways differently than static images. Yet most neuroimaging studies of food cue reactivity have relied on static images. This preliminary study aimed to explore neural responses in reward- and appetite-regulating brain regions to dynamic versus static presentations of high- and low-calorie food stimuli. Seventeen healthy adults (8 with healthy weight and 9 with overweight; mean age = 32.7 ± 10.1y; 53% female) completed a novel functional magnetic resonance imaging (fMRI) paradigm involving dynamic (video) and static (image) presentations of food and non-food object stimuli. Two fMRI runs were conducted: high-calorie food and object cues were presented in Run 1 and low-calorie food and object cues were presented in Run 2. Stimulus format (dynamic vs. static) was manipulated within each run, and analyses of format effects were conducted separately for the high- and low-calorie conditions. Primary analyses examined whether stimulus format (dynamic vs. static) elicited differential activation of visual food cues relative to non-food objects, with high-calorie and low-calorie conditions tested separately. Regions of interest included a priori reward- and appetite-related regions, including the amygdala, dorsal striatum, ventral striatum, insula, and substantia nigra/ventral tegmental area. Secondary whole-brain analyses and exploratory comparisons by weight status were conducted. Stimulus format did not significantly modulate activation to food cues relative to objects in a priori reward- and appetite-related regions for either high- or low-calorie foods. Whole-brain analyses showed that the dynamic-versus-static high-calorie food contrast (relative to objects) elicited greater activation in the right occipital fusiform gyrus. Frontal, insular, occipital, and postcentral activation was observed to the dynamic high-calorie food-versus-object contrast. Exploratory analyses showed that, for high-calorie foods, individuals with overweight showed greater dynamic-versus-static food-related activation (relative to objects) in the dorsal striatum than individuals with healthy weight; for low-calorie foods, individuals with healthy weight showed greater dynamic-versus-static food-related activation (relative to objects) in the substantia nigra/ventral tegmental area than individuals with overweight. In this pilot study, effect sizes for dynamic-versus-static differences in reward-related regions did not reach statistical significance, and thus findings should be interpreted with caution given the limited sample size. Dynamic cues were well tolerated and showed similar appeal compared with static images, while engaging broader networks related to perception, attention, and salience. Larger studies and designs that randomize the food cue type are needed to confirm and extend these observations.