March 2013
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15 Reads
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13 Citations
Physiological Psychology
The human averaged auditory evoked response (AER) to monaurally presented musical chord stimuli was recorded simultaneously from electrodes placed symmetrically over the two cerebral hemispheres at central and Wernicke (W) scalp locations. Stimulus presentation was quasi-random to the left (L) and right (R) ears of 14 normal-hearing right-handed male university students. The mean integrated amplitude over the initial 300 msec of the AER reflected asymmetries at the W locations as a function of hemisphere derivation and ear stimulated. The major interhemispheric difference observed when effects of contralateral auditory pathway-to-cortex projections had been equated was a significantly greater magnitude integrated amplitude response at the right (W2) scalp site to L-ear stimulation in comparison with the AER at the left (W1) cortical location to Rear stimulation. Differences of AERs between hemispheres summed across both ears stimulated conceived as attributable to additive auditory input showed a significantly greater integrated amplitude value at W2. When effects of contralateral auditory pathway predominance were examined, the AER integrated amplitude from W2 exceeded the hemisphere response at W1 to L-ear stimulation. The demonstrated asymmetries in the evoked response to musical chords may be associated with preponderance of the right hemisphere and saliency of the L ear for nonverbal, nonmeaningful auditory stimuli.