Hemispheric asymmetry and emotion: effects of nonverbal affective stimuli

The purpose of the present study was to investigate the cerebral processing of affect by measuring the electroencephalographic activity of the frontal lobes and electrodermal activity in response to a series of nonverbal affective stimuli. Cognitive and sensorimotor processes were minimized by employing a design that did not require subjects to perform any task other than attending to the stimuli. Summated frontal alpha activity was determined during nonemotional, positive, and negative stimuli. Changes in bilateral skin conductance were also measured during the presentation of the stimuli. Results demonstrated that there was bilateral activation of the frontal lobes in response to the positive affective stimuli. The level of activation of the frontal lobes was the same in response to both negative and nonemotional stimuli. There was no evidence of hemispheric asymmetry or gender-related differences in patterns of activation. Furthermore, there was no evidence of lateralization in the skin conductance response magnitude.