Food cue-elicited brain potentials in obese and healthy-weight individuals.

Abstract

In western societies the abundant availability of rewarding food is believed to contribute considerably to the current obesity epidemic. Obese individuals are assumed to be particularly sensitive and reactive to environmental food cues. Food cue reactivity suggests enhanced processing of food stimuli in the brain. Electrophysiological indices of information processing are event-related potentials (ERP). As is demonstrated in addiction and psychopathology research, amplitudes of long-latency ERPs (P3 and Late Positive Potentials [LPP]) are modulated by the motivational significance of processed information: in cue-exposure paradigms motivationally salient stimuli elicit larger ERP amplitudes than non-relevant stimuli. The present study investigated ERPs (P3, LPP, and an early ERP component between 150 and 300 ms) elicited by pictures of palatable foods and non-food control pictures in an obese ( N =20, 4 males, BMI: 36.69±6.47 kg/m 2 , age: 28.65±6.59 yr) and normal-weight sample ( N =20, 4 males; BMI: 22.68±1.53 kg/m 2 ; age: 28.65±6.08 yr). Overall, significantly enlarged ERP amplitudes were observed for food cues as compared to non-food cues at lateral parietal–occipital and lateral central–temporal electrode sites. Particularly parietal–occipital ERP amplitudes correlated positively with self-reported increase of food craving and physiological hunger during the exposure session. However, no differences between obese and normal-weight participants were observed. These findings demonstrate that food information is processed differently in the human brain as compared to non-food information, in a way that reflects the natural reinforcing value of food.