Satiety Does Not Affect Neuroaffective Electrophysiological Responses To Food-Related Or Emotional Visual Cues

Continuing to eat even when full leads to excessive calorie consumption and obesity. Thus, understanding brain responses to food cues when satiated has important implications for weight control interventions. We used the late positive potential (LPP, a component of the event-related potentials (ERP) indexing motivational relevance) to determine the extent to which satiety affects brain responses to images of highly palatable foods (high-fat, high-sugar), high and low motivationally relevant (pleasant, unpleasant) and neutral stimuli in a sample of obese (body mass index [BMI] >= 30 kg/m(2)) and lean (BMI < 25 kg/m(2)) individuals. Satiated individuals (N = 55, 21 with BMI >= 30 kg/m(2)) were fed a nutritional drink prior to the experimental session and were individually matched with 55 unsatiated individuals who saw the same images during a passive viewing task. Satiety did not affect LPP response to food-related or motivationally relevant cues in either BMI < 25 kg/m(2) or BMI >= 30 kg/m(2) individuals (p = .6). Irrespective of satiety, all participants showed larger LPPs as a function of the images' motivational relevance. There were no differences in LPP amplitude between BMI < 25 kg/m(2) and BMI >= 30 kg/m(2) individuals for any picture category, including food. However, within-group comparisons showed that BMI < 25 kg/m(2) individuals had larger LPPs to low motivationally relevant pleasant images than to food-related cues (p < .001); this difference was not significant for BMI >= 30 kg/m(2) individuals. Although satiety does not affect LPP responses to food-related cues, these results highlight the importance of evaluating reactivity to food-related cues in relation to other motivationally relevant stimuli.