Lukas J H
Int J Neurosci. 1981;12(2):137-45. doi: 10.3109/00207458108985796.
This study examined whether the efferent olivocochlear bundle (OCB) functions to attenuate irrelevant auditory stimuli during visual attention. Subjects either counted 8000 Hz, 50 dB SL target tone pips, or target letters flashed rapidly on a visual display. The target stimuli were randomly interspersed among nontarget stimuli to prevent ther subjects anticipating their occurrence (Naatanen, 1975). The auditory brainstem potentials were tape recorded for separate analyses of the target and nontarget tone pips. The nontarget tone pips were not significantly affected suggesting they were attenuated in the auditory task (intramodal effect) as well as during the visual task. During focused visual attention, the auditory nerve component to the target tone pips was significantly reduced in amplitude by 37.4% and increased in latency by 90 musec. Wave V generated partially from the inferior colliculus was also reduced in amplitude by 12.9%; however, this decrement, was not statistically significant. The use of 8000 Hz tone pips and random target presentation precluded middle ear muscle contractions producing these results. It was concluded that the efferent OCB which synapses on and inhibits the hair cells and axons within the cochlea may function during visual attention by attenuating irrelevant acoustic stimuli.
本研究考察了传出橄榄耳蜗束（OCB）在视觉注意力集中时是否发挥作用以衰减无关听觉刺激。受试者要么计数8000赫兹、50分贝声级的目标音脉冲，要么注视视觉显示屏上快速闪现的目标字母。目标刺激随机穿插在非目标刺激之中，以防止受试者预测其出现（纳塔宁，1975年）。听觉脑干电位通过磁带记录，以便分别分析目标音脉冲和非目标音脉冲。非目标音脉冲未受到显著影响，这表明它们在听觉任务（模态内效应）以及视觉任务期间被衰减。在集中视觉注意力时，目标音脉冲的听神经成分振幅显著降低了37.4%，潜伏期增加了90微秒。部分由下丘产生的V波振幅也降低了12.9%；然而，这种降低在统计学上并不显著。使用8000赫兹音脉冲和随机目标呈现排除了中耳肌肉收缩产生这些结果的可能性。得出的结论是，在耳蜗内与毛细胞和轴突形成突触并对其产生抑制作用的传出OCB，可能在视觉注意力集中时通过衰减无关听觉刺激发挥作用。
