Brain signature of food and alcohol stimuli processing: a comparative EEG study.

Background: Food and alcohol cues are potent motivational stimuli that engage neural systems supporting reward and approach-avoidance behavior. While EEG studies have largely emphasized event-related potentials, less is known about how sustained oscillatory dynamics differentiate appetitive cues with distinct biological and learned significance. Methods: EEG activity was recorded in healthy adults during passive viewing of food-related, alcohol-related, and matched neutral images using a paradigm optimized for prolonged exposure. Spectral power was analyzed across canonical frequency bands with cluster-based permutation statistics. Individual differences in alcohol use were assessed using the Alcohol Use Disorders Identification Test (AUDIT). Additional psychometric assessments included measures of depression (BDI-II), trait anxiety (STAI-Trait), eating behavior (DEBQ), and nicotine dependence (Fagerström). Results: Food and alcohol cues elicited dissociable oscillatory responses. Food images were associated with increased delta-band power over posterior and central regions, whereas alcohol images induced decreased delta power and increased alpha-band activity over parieto-occipital areas. These effects were most pronounced in individuals with higher AUDIT scores, while lower-AUDIT scorers showed no consistent oscillatory modulation. Psychometric scores indicated non-clinical levels of depression and anxiety across participants. Conclusion: The findings indicate that food and alcohol cues engage partially distinct oscillatory dynamics during passive viewing. EEG spectral measures capture sustained, state-dependent aspects of motivational processing, highlighting differences between biologically grounded and learned reward cues.