Efficient auditory coding
Efficient auditory coding
复制标题
DOI：
10.1038/nature04485
复制
发表时间：
2006-02-23
期刊：
影响因子：
64.8
通讯作者：
Lewicki, MS
中科院分区：
文献类型：
--
作者：
Smith, EC;Lewicki, MS
听觉神经代码必须服务于广泛的听觉任务，这些任务需要在时间和频率上具有很高的灵敏度，并且对自然声学环境中存在的各种声音都有效。有人提出（1-5），感觉系统可能已经进化出高效的编码策略，以最大限度地增加传递给大脑的信息，同时最大限度地减少所需的能量和神经资源。在这里，我们表明，对于自然的声音，完整的声波波形可以有效地表示与人口尖峰代码的基础上的非线性模型。在这个模型中，理想化的尖峰编码的精确的时间位置和幅度的基本声学特征。我们发现，当这些特征被优化用于编码自然声音或语音时，它们显示出与时域耳蜗滤波器估计惊人的相似性，具有与听觉神经纤维相似的频率带宽依赖性，并且产生比传统信号表示更大的编码效率。这些结果表明，听觉代码可能接近信息论的最佳和语音的声学结构可能是适应哺乳动物听觉系统的编码能力。
The auditory neural code must serve a wide range of auditory tasks that require great sensitivity in time and frequency and be effective over the diverse array of sounds present in natural acoustic environments. It has been suggested(1-5) that sensory systems might have evolved highly efficient coding strategies to maximize the information conveyed to the brain while minimizing the required energy and neural resources. Here we show that, for natural sounds, the complete acoustic waveform can be represented efficiently with a nonlinear model based on a population spike code. In this model, idealized spikes encode the precise temporal positions and magnitudes of underlying acoustic features. We find that when the features are optimized for coding either natural sounds or speech, they show striking similarities to time-domain cochlear filter estimates, have a frequency-bandwidth dependence similar to that of auditory nerve fibres, and yield significantly greater coding efficiency than conventional signal representations. These results indicate that the auditory code might approach an information theoretic optimum and that the acoustic structure of speech might be adapted to the coding capacity of the mammalian auditory system.