Emotion-related cerebral asymmetry: hemodynamics measured by functional ultrasound

This study assessed the use of transcranial Doppler ultrasound in detecting selective changes in cerebral blood flow velocity during emotional process es. The role of the respective hemispheres in emotional processing is contr oversial. Cerebral control of emotional processing has previously been inve stigated by analysis of patients with unilateral brain damage, experiments with selective stimulation of only one hemisphere, and more recently by ima ging techniques measuring local cerebral blood now. We investigated mean fl ow velocity continuously and simultaneously in both the right and left midd le cerebral arteries (MCAs) in 16 healthy right-handed young subjects at re st and during the performance of three tasks: task 1: 15 slides with nonemo tional content; task 2: 15 slides with negative emotional content; task 3: 15 slides with nonemotional content with different content from that in tas k 1. The three tasks produced significantly different effects on the right and left hemispheres. During the two nonemotional tasks the increase in mea n Row velocity over basal values was similar in the two MCAs (task Ir left MCA = 3.21 +/- 1.9%; right MCA = 3.63 +/- 2.1%; task 3: left MCA = 2.42 +/- 0.7%, right MCA = 2.56 +/- 1.3%); the negative emotional task was accompan ied by a significantly higher increase in the right (11.31 +/- 1.6%) than i n the left MCA (4.72 +/- 3.7%; analysis of variance two-way interaction: si de of recording x task, F = 43.6, P < 0.001). These results show the possib ility of obtaining specific functional information from bilateral transcran ial Doppler ultrasound and, suggest the involvement of the right hemisphere in emotional processing.