Towards a unifying basis of auditory thresholds: Distributions of the first-spike latencies of auditory-nerve fibers
Towards a unifying basis of auditory thresholds: Distributions of the first-spike latencies of auditory-nerve fibers
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DOI：
10.1016/j.heares.2007.09.014
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发表时间：
2008-04-01
期刊：
影响因子：
2.8
通讯作者：
Irvine, Dexter R. F.
中科院分区：
文献类型：
--
作者：
Heil, Peter;Neubauer, Heinrich;Irvine, Dexter R. F.
在安静环境中检测声音是听觉系统执行的最简单的任务，但对安静环境中声音感知检测阈值的神经机制仍不清楚。Heil和Neubauer [Heil， P., Neubauer， H., 2003]。基于时间求和的听觉阈值的统一基础。Proc。国家的。学会科学。[USA 100, 6151-6156]为一个简单的概率模型提供了证据，根据该模型，在任何时间点，刺激都有一定的超过阈值并被检测到的概率。因此，随着刺激持续时间的增加，检测事件的累积概率增加，性能提高，阈值幅度减小。这些过程的起源可以追溯到听觉系统中位于内毛细胞和传入听觉神经纤维（ANF）之间的第一个突触。在这里，我们为这个概率“连续观察”模型提供了进一步的支持。它是通过分析具有非常低的自发放电率的cat ANFs在不同振幅的音调中的第一峰的潜伏期分布而得出的。这些光纤中的第一个尖峰可以被认为是检测事件。我们表明，正如预测的那样，分布可以用三个独立子事件发生的联合概率来解释，其中每个子事件发生的概率与低通滤波后的刺激幅度成正比。单个anf的“时间整合”功能来源于它们的第一峰潜伏期，在形状上与“时间整合”功能非常相似，后者将知觉层面的阈值声压水平与刺激持续时间联系起来。这进一步支持了在听觉神经水平上决定第一次（和其他）诱发尖峰的时间的机制与感知水平上的检测阈值之间的密切联系。讨论了膨胀幂律非线性的可能起源和一些泛函结果。(C) 2007 Elsevier B.V.版权所有
Detecting sounds in quiet is the simplest task performed by the auditory system, but the neural mechanisms underlying perceptual detection thresholds for sounds in quiet are still not understood. Heil and Neubauer [Heil, P., Neubauer, H., 2003. A unifying basis of auditory thresholds based on temporal summation. Proc. Natl. Acad. Sci. USA 100, 6151-6156] have provided evidence for a simple probabilistic model according to which the stimulus, at any point in time, has a certain probability of exceeding threshold and being detected. Consequently, as stimulus duration increases, the cumulative probability of detection events increases, performance improves, and threshold amplitude decreases. The origin of these processes was traced to the first synapse in the auditory system, between the inner hair cell and the afferent auditory-nerve fiber (ANF). Here we provide further support for this probabilistic "continuous-look" model. It is derived from analyses of the distributions of the latencies of the first spikes of cat ANFs with very low spontaneous discharge rates to tones of different amplitudes. The first spikes in these fibers can be considered detection events. We show that, as predicted, the distributions can be explained by the joint probability of the occurrence of three independent sub-events, where the probability of each of those occurring is proportional to the low-pass filtered stimulus amplitude. The "temporal integration" functions of individual ANFs, derived from their first-spike latencies, are remarkably similar in shape to "temporal integration" functions, which relate threshold sound pressure level at the perceptual level to stimulus duration. This further supports a close link between the mechanisms determining the timing of the first (and other) evoked spikes at the level of the auditory nerve and detection thresholds at the perceptual level. The possible origin and some functional consequences of the expansive power-law non-linearity are discussed. (C) 2007 Elsevier B.V. All rights reserved.