Neural modulation tuning characteristics scale to efficiently encode natural sound statistics.
Neural modulation tuning characteristics scale to efficiently encode natural sound statistics.
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DOI：
10.1523/jneurosci.0966-10.2010
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发表时间：
2010-11-24
期刊：
影响因子：
--
通讯作者：
Escabí MA
中科院分区：
文献类型：
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作者：
Rodríguez FA;Chen C;Read HL;Escabí MA
有效编码假说认为，神经和感知灵敏度的进化是为了忠实地代表生物相关的感觉信号。在这里，我们的特点是spectrotemporal调制统计的几个自然的声音合奏，并研究神经元编码这些统计在中央核的下丘（CNIC）的猫。我们报告说，调制调谐在CNIC匹配，以均衡自然声音的调制功率。具体而言，自然声音表现出频谱和时间调制之间的权衡，表现为1/f调制功率谱（MPS）。神经调谐与自然声音MPS高度重叠，神经元逼近比例分辨率滤波器，其中调制带宽随特征调制频率缩放，这是之前在人类心理声学中描述的行为。我们证明，这种神经缩放反对自然声音的1/f缩放，并通过均衡它们的MPS来增强自然声音的表示。因此，CNIC中的调制调谐可能已经演变为以与效率原则一致的方式表示自然声音调制，并且所得到的特性可能是感知分辨率的基础。
The efficient-coding hypothesis asserts that neural and perceptual sensitivity evolved to faithfully represent biologically relevant sensory signals. Here we characterized the spectrotemporal modulation statistics of several natural sound ensembles and examined how neurons encode these statistics in the central nucleus of the inferior colliculus (CNIC) of cats. We report that modulation-tuning in the CNIC is matched to equalize the modulation power of natural sounds. Specifically, natural sounds exhibited a tradeoff between spectral and temporal modulations, which manifests as 1/f modulation power spectrum (MPS). Neural tuning was highly overlapped with the natural sound MPS and neurons approximated proportional resolution filters where modulation bandwidths scaled with characteristic modulation frequencies, a behavior previously described in human psychoacoustics. We demonstrate that this neural scaling opposes the 1/f scaling of natural sounds and enhances the natural sound representation by equalizing their MPS. Modulation tuning in the CNIC may thus have evolved to represent natural sound modulations in a manner consistent with efficiency principles and the resulting characteristics likely underlie perceptual resolution.