Hemispheric asymmetries in the perception of emotions
The purpose of this study is investigating differential hemispheric activations in the perception of emotion. Electroencephalography (EEG) data were recorded while subjects viewed pictures of three types of emotional contents (negatively arousing, calm, and positively arousing) chosen from the International Affective Picture System (IAPS). The results showed that in the upper alpha (10~12 Hz) frequency band subjects showed greater activation of the left hemisphere than the right hemisphere in response to the positively arousing pictures, whereas negative emotional pictures resulted in greater activation of the right hemisphere relative to the left. The other frequency bands, including lower alpha (8~10 Hz) and gamma (30~45 Hz), did not show any significant interaction effects between emotion type and hemispheric activation. These findings are of practical importance in neuroadaptive system design whose functional characteristics of the system change in response to meaningful variations in the user’s emotional states measured by brain signals.