McPherson D L, Starr A
Program in Audiology, Brigham Young University, Provo, UT 84602, USA
Hear Res. 1995 Sep;89(1-2):162-71. doi: 10.1016/0378-5955(95)00134-1.
Binaural interaction in the brainstem and middle latency auditory evoked potentials to intensity (dI) and timing differences (dT) between the two ears was studied in 10 normal hearing young adults. A component reflecting binaural interaction in the brainstem potentials occurred at approximately 7 ms and was of largest amplitude when dI and dT were 0. The latency of the binaural interaction component gradually shifted and its amplitude decreased as dI or dT increased and binaural interaction became undetectable when dI = 16 dB or when dT > or = 1.6 ms. In the middle latency potentials binaural interaction components peaking at 20, 32, and 45 ms were defined that were also largest when dI and dT = 0. The latency of the interaction did not shift with changes in dT and dI whereas the amplitude gradually decreased but binaural interaction components were still evident even at the largest values of dI (30 dB) and dT (3 ms). Psychophysical judgments of binaural perceptions showed binaural fusion of the stimuli to persist with dT values up to 1.6 ms and that lateralization of the intracranial image was complete when either dT = 1.6 ms or when dI = 16 dB. The results suggest that the presence of a binaural interaction component of auditory brainstem potentials correlates with the fusion of binaural click stimuli and the amplitude of the binaural interaction component correlates inversely with the degree of lateralization of the intracranial image. Binaural interaction components of middle latency potentials persist and continue to change even after the binaural stimuli cannot be fused.
对10名听力正常的年轻成年人进行了研究，观察其脑干中的双耳相互作用以及双耳间强度差异（dI）和时间差异（dT）诱发的中潜伏期听觉诱发电位。反映脑干电位中双耳相互作用的一个成分出现在约7毫秒处，当dI和dT为0时振幅最大。随着dI或dT增加，双耳相互作用成分的潜伏期逐渐偏移，其振幅减小，当dI = 16分贝或dT≥1.6毫秒时，双耳相互作用无法检测到。在中潜伏期电位中，定义了在20、32和45毫秒达到峰值的双耳相互作用成分，当dI和dT = 0时这些成分也最大。相互作用的潜伏期不随dT和dI的变化而偏移，而振幅逐渐减小，但即使在dI（30分贝）和dT（3毫秒）的最大值时，双耳相互作用成分仍然明显。双耳感知的心理物理学判断表明，刺激的双耳融合在dT值高达1.6毫秒时仍然存在，当dT = 1.6毫秒或dI = 16分贝时，颅内图像的定位完成。结果表明，听觉脑干电位中双耳相互作用成分的存在与双耳点击刺激的融合相关，双耳相互作用成分的振幅与颅内图像的定位程度呈负相关。即使双耳刺激无法融合，中潜伏期电位的双耳相互作用成分仍然存在并继续变化。
