The Effects of Visual and Auditory Stimulation on EEG Power Spectra during the Viewing of Disgust-Eliciting Videos

Disgust is an affect produced in response to something that is offensive or unpleasant. This emotion is associated with feelings of dizziness and vomiting and, in severe cases, mental illnesses, such as obsessive compulsive disorder and depression. Most experimental electroencephalography (EEG) studies on disgust have identified activated brain areas or disgust elicitors or examined the effects of unimodal stimulation, such as visual, auditory, olfactory, or haptic stimulation. This EEG study examined the effects of disguste liciting visual stimuli that were presented with different auditory stimuli in relative power spectrum analyses of the delta-, theta-, alpha-, beta-, and gamma-wave bands. The EEG data were collected while the participants watched disgust-eliciting videos of body mutilation and disgusting creatures with the original soundtrack or auditory stimuli. Two types of auditory stimuli were used: relaxing music or exciting music. The EEG power spectra of all of the frequency bands were lower in response to videos with auditory stimuli compared with videos with the original soundtracks. Additionally, the mood of the music aroused different responses depending on the type of disgust elicitor, and the types of music that reduced disgust differed according to the different types of disgust elicitors.