Variability of frontal alpha wave in response to mood induction via visual stimulus: A quantitative electroencephalographic study

Background: one of the prime areas in psychiatry is concerned with assessing emotions. assessment of physiologic responses can be attained by various approaches. one of them is analyzing electroencephalography (eeg). objectives: in current study,we aimed to assess alpha wave in frontal region after inducing specific emotion by showing evocative video clips. materials and methods: after a baseline in eye open situation recording,we showed 5 video clips that each induced specific emotions from five major ones (neutral,happiness,sadness,anger,fear) to 66 healthy individuals,including 33 males and 33 females between 20 - 40 years old and eeg recording was continued simultaneously. then,we analyzed their brain waves. absolute power of alpha wave bands (alpha 1 and alpha 2) in frontal region (fz,f4,f3) was analyzed via wilcoxon test. results: with respect to eye open situation,all video clips made significant change in alpha 2 in f3 and f4 (p < 0.001) but not in fz except for sadness. sad inductive clip made a significant increase in alpha 2 in fz,also alpha 1 in f3 and f4 (p < 0.001). fz had no significant variability in all other emotions. conclusions: the most trenchant impact with respect to alpha band was sadness,and the most exclusive finding in fz was alpha 2. nonetheless,in two other zones (f3,f4),alpha 1 was exclusive and alpha 2 variability was non-exclusive. it appears plausible that sadness activates neuron groups,which are involved in generating alpha waves. © 2016,mazandaran university of medical sciences.