Department of Mathematics, Seattle University, Seattle, Washington 98122, USA.
Cluster of Excellence "Hearing4all" and Research Centre Neurosensory Science, Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky University, Oldenburg, Germany.
J Acoust Soc Am. 2018 Oct;144(4):2116. doi: 10.1121/1.5056171.
Auditory perception depends on multi-dimensional information in acoustic signals that must be encoded by auditory nerve fibers (ANF). These dimensions are represented by filters with different frequency selectivities. Multiple models have been suggested; however, the identification of relevant filters and type of interactions has been elusive, limiting progress in modeling the cochlear output. Spike-triggered covariance analysis of barn owl ANF responses was used to determine the number of relevant stimulus filters and estimate the nonlinearity that produces responses from filter outputs. This confirmed that ANF responses depend on multiple filters. The first, most dominant filter was the spike-triggered average, which was excitatory for all neurons. The second and third filters could be either suppressive or excitatory with center frequencies above or below that of the first filter. The nonlinear function mapping the first two filter outputs to the spiking probability ranged from restricted to nearly circular-symmetric, reflecting different modes of interaction between stimulus dimensions across the sample. This shows that stimulus encoding in ANFs of the barn owl is multidimensional and exhibits diversity over the population, suggesting that models must allow for variable numbers of filters and types of interactions between filters to describe how sound is encoded in ANFs.
听觉感知取决于声学信号中的多维信息，这些信息必须由听觉神经纤维 (ANF) 进行编码。这些维度由具有不同频率选择性的滤波器来表示。已经提出了多种模型；然而，相关滤波器的识别和相互作用的类型一直难以捉摸，这限制了对耳蜗输出进行建模的进展。利用仓鸮听觉神经纤维反应的脉冲触发协方差分析来确定相关刺激滤波器的数量，并估计从滤波器输出产生反应的非线性。这证实了听觉神经纤维反应取决于多个滤波器。第一个、最主要的滤波器是脉冲触发平均，它对所有神经元都是兴奋性的。第二个和第三个滤波器可以是兴奋性的，也可以是抑制性的，其中心频率高于或低于第一个滤波器。将前两个滤波器输出映射到脉冲概率的非线性函数从受限到几乎圆形对称，反映了在样本中刺激维度之间不同的相互作用模式。这表明，仓鸮听觉神经纤维中的刺激编码是多维的，并在种群中表现出多样性，这表明模型必须允许滤波器的数量和滤波器之间相互作用的类型发生变化，以描述声音是如何在听觉神经纤维中编码的。
