Tenke C E, Bruder G E, Towey J P, Leite P, Sidtis J J
Department of Biopsychology, New York State Psychiatric Institute, New York 10032.
Psychophysiology. 1993 Jan;30(1):62-70. doi: 10.1111/j.1469-8986.1993.tb03205.x.
Electrophysiologic correlates of perceptual asymmetry for dichotic pitch discrimination were investigated in 20 normal subjects. Brain event-related potentials (ERPs) elicited by dichotic pairs and binaural probe tones in the Complex Tone Test (Sidtis, 1981) were recorded from homologous scalp locations over left and right hemispheres (F3, F4; C3, C4; P3, P4; O1, O2). Baseline-to-peak amplitudes were measured for N100, P200, and a late positive complex consisting of P350, P550, and slow wave. A left ear advantage (LEA) was evident in 70% of the subjects, and hemispheric asymmetries related to this behavioral asymmetry were found for P350 and P550 amplitudes to probe stimuli. Subjects with a strong LEA had greater amplitudes over the right hemisphere than the left, whereas subjects with little or no LEA showed a nonsignificant trend toward the opposite hemispheric asymmetry. Hemispheric asymmetry of these late ERPs at parietal and occipital sites was highly correlated with behavioral asymmetry. These findings suggest the utility of electrophysiological measures in assessing hemispheric asymmetries for processing complex pitch information.
在20名正常受试者中研究了用于双耳音高辨别感知不对称的电生理相关性。在复杂音调测试（Sidtis，1981）中，由双耳对和双耳探测音引发的脑事件相关电位（ERP）从左、右半球的同源头皮位置（F3、F4；C3、C4；P3、P4；O1、O2）记录。测量了N100、P200以及由P350、P550和慢波组成的晚期正复合体的基线到峰值幅度。70%的受试者表现出左耳优势（LEA），并且发现与这种行为不对称相关的半球不对称存在于探测刺激的P350和P550幅度中。具有强烈LEA的受试者右半球的幅度大于左半球，而具有轻微或无LEA的受试者则表现出向相反半球不对称的不显著趋势。顶叶和枕叶部位这些晚期ERP的半球不对称与行为不对称高度相关。这些发现表明电生理测量在评估处理复杂音调信息的半球不对称方面的效用。
