This study investigated the feasibility of magnetoencephalography for objective assessment of emotion and stress by comparing amplitude modulations of alpha rhythm due to the viewing of emotional pictures in a normal (control) condition and a fasting-induced stress condition. In the control condition, viewing both pleasant pictures (P) and unpleasant pictures (U) suppressed alpha rhythm significantly more than viewing neutral pictures (N). In the fasting condition however, U suppressed alpha rhythm significantly more than P or N. Since it is know that alpha rhythm is suppressed by attention to visual inputs, these results suggest that attention to pleasant stimuli is impaired by fasting-induced stress.
Figure. Three-dimensional map showing the trend of “alpha rhythm amplitude modulation” against “emotional valence” and “arousal”. The declines of the “control” and “fasting” planes indicate that alpha rhythm is suppressed by arousal in the normal (control) condition, while it is suppressed by emotional valence in the fasting-induced stress condition.