Modulation power and phase spectrum of natural sounds enhance neural encoding performed by single auditory neurons
Modulation power and phase spectrum of natural sounds enhance neural encoding performed by single auditory neurons
复制标题
DOI：
10.1523/jneurosci.2449-04.2004
复制
发表时间：
2004-10-13
影响因子：
5.3
通讯作者：
Theunissen, FE
中科院分区：
文献类型：
--
作者：
Hsu, A;Woolley, SMN;Theunissen, FE
我们研究了神经编码的合成和自然的声音由单个神经元在雄性斑胸草雀的听觉系统，通过估计的互信息随时间变化的平均放电率的神经元反应。使用一种新的参数方法估计有限的数据的互信息，我们测试的假设，歌曲和歌曲样的合成声音将优先编码相对于其他复杂的，但非歌曲样的合成声音。为了验证这一假设，我们设计了两个合成刺激：合成歌曲，匹配功率的频谱-时间调制，但缺乏调制相位结构的斑胸草雀的歌曲和噪音与统一的频带限制的频谱-时间调制。通过将神经选择性定义为相对互信息，我们发现鸣禽的听觉系统对类似歌声的声音表现出选择性。这种选择性在听觉系统中沿着向上的处理阶段以分层的方式增加。中脑神经元以最高的信息速率和效率对合成歌曲作出反应，因此对歌曲的频谱-时间调制具有选择性。初级前脑神经元对斑胸草雀鸣唱和合成鸣唱的信息量均高于噪声刺激。次级前脑神经元对斑胸草雀鸣唱的反应最高，因此对它的特定调制相位关系具有选择性。我们还评估了三个响应属性对这种选择性的相对贡献：（1）尖峰可靠性，（2）速率分布熵，和（3）带宽。我们发现，速率分布和带宽，但不是可靠性负责较高的平均信息速率发现歌曲般的声音。
We examined the neural encoding of synthetic and natural sounds by single neurons in the auditory system of male zebra finches by estimating the mutual information in the time-varying mean firing rate of the neuronal response. Using a novel parametric method for estimating mutual information with limited data, we tested the hypothesis that song and song-like synthetic sounds would be preferentially encoded relative to other complex, but non-song-like synthetic sounds. To test this hypothesis, we designed two synthetic stimuli: synthetic songs that matched the power of spectral - temporal modulations but lacked the modulation phase structure of zebra finch song and noise with uniform band-limited spectral - temporal modulations. By defining neural selectivity as relative mutual information, we found that the auditory system of songbirds showed selectivity for song-like sounds. This selectivity increased in a hierarchical manner along ascending processing stages in the auditory system. Midbrain neurons responded with highest information rates and efficiency to synthetic songs and thus were selective for the spectral - temporal modulations of song. Primary forebrain neurons showed increased information to zebra finch song and synthetic song equally over noise stimuli. Secondary forebrain neurons responded with the highest information to zebra finch song relative to other stimuli and thus were selective for its specific modulation phase relationships. We also assessed the relative contribution of three response properties to this selectivity: ( 1) spiking reliability, ( 2) rate distribution entropy, and ( 3) bandwidth. We found that rate distribution and bandwidth but not reliability were responsible for the higher average information rates found for song-like sounds.