Neural regulatory mechanism of desire for food: revealed by magnetoencephalography.

Currently, little is known about the brain function that allows individuals to suppress eating behavior. The present study used magnetoencephalography (MEG) to examine changes in neural activity over time that were related to suppression of motivation to eat in 11 healthy males. The MEG experiment consisted of four motivation sessions and four suppression sessions in an alternating and counterbalanced order. During MEG recordings, participants viewed a set of food pictures and mosaic pictures projected onto a screen, and were then asked to rate their motivation to eat and the suppression of the motivation to eat during the recordings. The present study demonstrated a higher β-band (13-25 Hz) event-related synchronization (ERS) level during the suppression sessions relative to the motivation sessions in the left supplementary motor area (SMA) 200-300 ms after the start of food picture presentation. Similar differences were also observed in θ-band (4-8 Hz) event-related desynchronization (ERD) in the left dorsolateral prefrontal cortex (DLPFC) after 500-600 ms. Negative relationships were observed between these levels of MEG responses and the number of food items for which the participants reported the motivation to eat during the MEG recordings. These findings indicate that the left DLPFC and SMA, particularly the DLPFC, play prominent roles in the suppression of motivation to eat. This may help to clarify the temporal aspects of the neural basis of self-control of appetitive motivation as well as aid development of self-control strategies such as cognitive behavioral therapy for patients with disordered appetite.