Department of Psychology, University of Minnesota, 75 East River Parkway, Minneapolis, Minnesota 55455, USA.
J Acoust Soc Am. 2019 Aug;146(2):1475. doi: 10.1121/1.5123391.
The effects of selectively attending to a target stimulus in a background containing distractors can be observed in cortical representations of sound as an attenuation of the representation of distractor stimuli. The locus in the auditory system at which attentional modulations first arise is unknown, but anatomical evidence suggests that cortically driven modulation of neural activity could extend as peripherally as the cochlea itself. Previous studies of selective attention have used otoacoustic emissions to probe cochlear function under varying conditions of attention with mixed results. In the current study, two experiments combined visual and auditory tasks to maximize sustained attention, perceptual load, and cochlear dynamic range in an attempt to improve the likelihood of observing selective attention effects on cochlear responses. Across a total of 45 listeners in the two experiments, no systematic effects of attention or perceptual load were observed on stimulus-frequency otoacoustic emissions. The results revealed significant between-subject variability in the otoacoustic-emission measure of cochlear function that does not depend on listener performance in the behavioral tasks and is not related to movement-generated noise. The findings suggest that attentional modulation of auditory information in humans arises at stages of processing beyond the cochlea.
在包含干扰刺激的背景中选择性地关注目标刺激的效果可以在声音的皮质表示中观察到，表现为对干扰刺激表示的衰减。注意力调节最初出现的听觉系统中的位置尚不清楚，但解剖学证据表明，皮质驱动的神经活动调制可以延伸到耳蜗本身的外围。以前的选择性注意研究使用耳声发射来探测在不同注意力条件下的耳蜗功能，但结果喜忧参半。在当前的研究中，两项实验结合了视觉和听觉任务，以最大限度地提高注意力的持续性、感知负载和耳蜗动态范围，试图提高在耳蜗反应上观察到选择性注意效果的可能性。在两项实验中的总共 45 名听众中，在刺激频率耳声发射上没有观察到注意力或感知负载的系统影响。结果表明，耳蜗功能的耳声发射测量值存在显著的个体间变异性，这种变异性不依赖于行为任务中的听众表现，也与运动产生的噪声无关。这些发现表明，人类听觉信息的注意力调节出现在耳蜗以外的处理阶段。
