Tuning to natural stimulus dynamics in primary auditory cortex
Tuning to natural stimulus dynamics in primary auditory cortex
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DOI：
10.1016/j.cub.2005.12.013
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发表时间：
2006-02-07
期刊：
影响因子：
9.2
通讯作者：
Schnupp, JWH
中科院分区：
文献类型：
--
作者：
Garcia-Lazaro, JA;Ahmed, B;Schnupp, JWH
自然音景的振幅和音高波动通常表现出“1/f谱”[1，2]，这意味着音高或响度的大的突然变化在自然界中发生的频率比温和的渐进波动低。此外，据报道，人类听众更喜欢1/f分布的随机旋律，而不是具有更快（1/f（0））或更慢（1/f（2））动态的旋律[3]。因此，人们可能会怀疑中枢听觉系统中的神经元可能被调谐到1/f动态，特别是考虑到最近的报告提供了初级视觉皮层中调谐到1/f动态的证据[4]。为了测试初级听觉皮层（A1）中的神经元是否被调谐到1/f动态，我们记录了对随机音调复合体的反应，其中基频和包络由统计独立的“1/f（伽马）随机游走”确定，伽马值设置为0.5和4之间。许多Al神经元表现出明显的调谐，并以较高的放电率对y在1和1.5之间的刺激作出反应。响应模式引起的1/f（伽马）刺激的伽马值接近1更可重复。这些发现表明，听觉皮层确实是调谐到1/f动态通常发现在自然声景的统计分布。
The amplitude and pitch fluctuations of natural soundscapes often exhibit "1/f spectra" [1, 2], which means that large, abrupt changes in pitch or loudness occur proportionally less frequently in nature than gentle, gradual fluctuations. Furthermore, human listeners reportedly prefer 1/f distributed random melodies to melodies with faster (1/f(0)) or slower (1/f(2)) dynamics [3]. One might therefore suspect that neurons in the central auditory system may be tuned to 1/f dynamics, particularly given that recent reports provide evidence for tuning to 1/f dynamics in primary visual cortex [4]. To test whether neurons in primary auditory cortex (A1) are tuned to 1/f dynamics, we recorded responses to random tone complexes in which the fundamental frequency and the envelope were determined by statistically independent " 1/f(gamma) random walks," with gamma set to values between 0.5 and 4. Many Al neurons showed clearevidence of tuning and responded with higher firing rates to stimuli with y between 1 and 1.5. Response patterns elicited by 1/f(gamma) stimuli were more reproducible for values of gamma close to 1. These findings indicate that auditory cortex is indeed tuned to the 1/fdynamics commonly found in the statistical distributions of natural soundscapes.