Cortical responses to food stimuli in eating-disorder symptoms: An EEG study of approach-avoidance motivation

Eating disorders involve disturbances in body perception with substantial psychological and physical consequences. Neurobiological and motivational processes may help explain why these symptoms emerge and persist. This study examined cortical responses to food stimuli, indexed by frontal alpha asymmetry (FAA) within an approach-avoidance framework, to clarify their relation to eating-disorder symptoms in a nonclinical sample. Eighty adults aged 18-40 completed an EEG task with food images varying in calorie content (low vs. high) and freshness (fresh vs. rotten), alongside self-report measures of eating-disorder symptoms and cognitive flexibility. Regression analyses showed that FAA was associated with global symptom severity and, more specifically, with dietary restraint; after controlling for age, sex, and BMI, only the association with restraint remained significant. Frontal asymmetry may therefore index individual differences in restrictive eating rather than serve as a general neurophysiological marker of eating-disorder pathology. The behavioural data supported the task itself: participants clearly distinguished stimuli by calorie content and freshness, rating fresh foods more favourably and responding faster to rotten ones, consistent with heightened salience for aversive food cues. Cognitive flexibility, by contrast, was not related to eating-disorder symptoms in this sample. Taken together, these findings suggest that FAA may reflect motivational processes underlying restrictive eating tendencies in nonclinical populations and support the use of task-based neurophysiological paradigms for studying these processes.