Temporal processing and adaptation in the songbird auditory forebrain
Temporal processing and adaptation in the songbird auditory forebrain
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DOI：
10.1016/j.neuron.2006.08.030
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发表时间：
2006-09-21
期刊：
影响因子：
16.2
通讯作者：
Doupe, Allison J.
中科院分区：
文献类型：
--
作者：
Nagel, Katherine I.;Doupe, Allison J.
鸣禽的听觉神经元必须以许多音量编码自然声音的动态。我们研究了神经编码如何依赖于刺激强度的分布。利用反向相关，我们将对调幅声音的响应建模为线性滤波器和非线性增益函数的输出，然后询问滤波器和非线性如何依赖于刺激均值和方差。过滤器的形状强烈依赖于平均幅度(体积)：在低平均值时，大多数神经元在许多毫秒内整合声音，而在高平均值时，神经元更多地对幅度的局部变化做出反应。增加幅度调制的方差(对比度)对滤光片形状的影响较小，但降低了大多数细胞的放电增益。在统计数据发生变化后，滤波器和增益的变化都会迅速发生，这表明它们代表了处理过程中的非线性。这些变化可能允许神经元在更大的动态范围内有效地发出信号，这让人想起其他感觉系统的发现。
Songbird auditory neurons must encode the dynamics of natural sounds at many volumes. We investigated how neural coding depends on the distribution of stimulus intensities. Using reverse-correlation, we modeled responses to amplitude-modulated sounds as the output of a linear filter and a nonlinear gain function, then asked how filters and nonlinearities depend on the stimulus mean and variance. Filter shape depended strongly on mean amplitude (volume): at low mean, most neurons integrated sound over many milliseconds, while at high mean, neurons responded more to local changes in amplitude. Increasing the variance (contrast) of amplitude modulations had less effect on filter shape but decreased the gain of firing in most cells. Both filter and gain changes occurred rapidly after a change in statistics, suggesting that they represent nonlinearities in processing. These changes may permit neurons to signal effectively over a wider dynamic range and are reminiscent of findings in other sensory systems.