The role of the right hemisphere in the physiological and cognitive components of emotional processing

Right hemisphere specialization for emotional processing was investigated using behavioral and psychophysiological methods. Fifty undergraduates were shown slides depicting negative emotional and neutral scenes briefly lateralized to the right or left cerebral hemispheres and asked to categorize each as emotional or neutral. Pulse volume and heart rate (HR) measured physiological processing and reaction time measured cognitive processing. The largest vasoconstriction responses and HR deceleration were obtained for emotional items in the right hemisphere. However, reaction time failed to show right hemisphere superiority in perceptual/cognitive processing, demonstrating instead slowest responses to emotional stimuli presented to the right hemisphere together with evidence for left hemisphere competence. Selective right hemispheric activation in autonomic responses, combined with the lack of right hemisphere specialization in the cognitive task, suggests that the physiological response system rather than the perceptual/cognitive system is the locus of the right hemisphere superiority for emotion.