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. Assessing physiologic responses can be attained by various approaches, one of which is analyzing EEG. Objectives: In this study, we aimed to assess Alpha wave in the frontal region after inducing specific emotion by showing evocative video clips. Methods: After eye open recording at baseline, we showed five video clips that each induced specific emotions from the five major emotions (neutral, happiness, sadness, anger, and fear) to 66 healthy individuals, including 33 males and 33 females aged 20 40 years simultaneously. Then, we analyzed their brain waves. Absolute power of Alpha wave band (1, 2, total) in the frontal region (FZ, F4, F3) was analyzed via Wilcoxon test. Results: With respect to eye open situation, all video clips significantly changed Alpha 2 in F3 and F4 (P < 0.001), but not in Fz except for sadness. The sad clip significantly increased Alpha 2 in Fz and 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 Alpha2. Nonetheless, in two other zones (F3, F4), Alpha1 was exclusive and Alpha2 variability was non-exclusive. It appears plausible that sadness activates neuron groups, which are involved in generating Alpha waves.