Responses of neurons to click-pairs as simulated echoes: Auditory nerve to auditory cortex
Responses of neurons to click-pairs as simulated echoes: Auditory nerve to auditory cortex
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DOI：
10.1121/1.428199
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发表时间：
1999-12-01
影响因子：
2.4
通讯作者：
Batra, R
中科院分区：
文献类型：
--
作者：
Fitzpatrick, DC;Kuwada, S;Batra, R
当两个相同的声音从不同的位置发出且间隔很短时，感知到的是主声音位置处的单个声源。这种“优先效应”是一种重要的行为现象，其神经基础正在得到越来越多的研究。在这份报告中，记录了未麻醉动物上行听觉系统的几个结构对具有不同刺激间隔的成对喀哒声的神经反应。测试的结构是听神经、前腹侧耳蜗核、上橄榄复合体、下丘和初级听觉皮层。主要发现是前导声音（调节器）对滞后声音（探头）响应的抑制效果的持续时间逐渐增加。第一次主要增加发生在下脑干和下丘之间，第二次主要增加发生在下丘和听觉皮层之间。在来自听神经、耳蜗核和上橄榄复合体的神经元中，对于类似于 2 ms 的调节器和探针间隔，对探针的响应平均恢复 50%。在下丘中，平均间隔大约 7 毫秒时恢复 50%，而听觉皮层则在大约 20 毫秒时恢复。尽管平均恢复时间有所增加，但每个结构中的一些神经元在优先时间窗口内对探针表现出较大的响应（类似于点击的 1-4 毫秒）。这表明在优先效应期间，回声的一些信息被保留。在另一个极端，对于一些皮质神经元，调节器抑制探针反应的时间间隔长达 300 毫秒。这与行为结果一致，显示主导声音在优先效应之外的较长时间内占据主导地位。随着信息的提升，其他转变包括神经后面的结构中恢复功能形状的增加，以及“调整”到听觉皮层中特定调节器探针间隔的神经元。后者让人想起蝙蝠中调节回声延迟的神经元，并且可能有助于感知声学空间的大小。 (C) 1999 年美国声学学会。 [S0001-4966(99)07612-2]。
When two identical sounds are presented from different locations with a short interval between them, the perception is of a single sound source at the location of the leading sound. This "precedence effect" is an important behavioral phenomenon whose neural basis is being increasingly studied. For this report, neural responses were recorded to paired clicks with varying interstimulus intervals, from several structures of the ascending auditory system in unanesthetized animals. The structures tested were the auditory nerve, anteroventral cochlear nucleus, superior olivary complex, inferior colliculus, and primary auditory cortex. The main finding is a progressive increase in the duration of the suppressive effect of the leading sound (the conditioner) on the response to the lagging sound (the probe). The first major increase occurred between the lower brainstem and inferior colliculus, and the second between the inferior colliculus and auditory cortex. In neurons from the auditory nerve, cochlear nucleus, and superior olivary complex, 50% recovery of the response to the probe occurred, on average, for conditioner and probe intervals of similar to 2 ms. In the inferior colliculus, 50% recovery occurred at an average separation of similar to 7 ms, and in the auditory cortex at similar to 20 ms. Despite these increases in average recovery times, some neurons in every structure showed large responses to the probe within the time window for precedence (similar to 1-4 ms for clicks). This indicates that during the period of the precedence effect, some information about echoes is retained. At the other extreme, for some cortical neurons the conditioner suppressed the probe response for intervals of up to 300 ms. This is in accord with behavioral results that show dominance of the leading sound for an extended period beyond that of the precedence effect. Other transformations as information ascended included an increased variety in the shapes of the recovery functions in structures subsequent to the nerve, and neurons "tuned" to particular conditioner-probe intervals in the auditory cortex. These latter are reminiscent of neurons tuned to echo delay in bats, and may contribute to the perception of the size of the acoustic space. (C) 1999 Acoustical Society of America. [S0001-4966(99)07612-2].