Neural Coding of Periodicity in Marmoset Auditory Cortex
Neural Coding of Periodicity in Marmoset Auditory Cortex
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DOI：
10.1152/jn.00281.2009
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发表时间：
2010-04-01
影响因子：
2.5
通讯作者：
Wang, Xiaoqin
中科院分区：
文献类型：
--
作者：
Bendor, Daniel;Wang, Xiaoqin
王晓东，王晓东，王晓东。狨猴听觉皮层周期性的神经编码。中国生物医学工程学报（自然科学版），2009,31(4):559 - 567。首次发表于2010年2月10日；doi: 10.1152 / jn.00281.2009。音高，即我们对音阶高低的感知，关键取决于声音的周期性。如果一个声音信号暂时抖动，使其成为非周期性的，即使通常与音高共变的其他声学特征不变，音高也将不再被感知。以前研究音高的电生理研究通常只使用周期性的声刺激，因此这些研究无法区分音高的神经表征和仅与音高相关的声学特征。在本报告中，我们研究了醒着的狨猴（Callithrix jacchus）的听觉皮层中周期性重复率的神经编码，这是一种随音高共变的声学特征。我们首先检查单个神经元是否对不同周期声信号表现出相似的重复率调谐。接下来，我们测量这些神经表征对声信号的时间规律性有多敏感。我们发现整个听觉皮层的神经元随声信号的重复频率而变化其放电速率。然而，类似的重复频率调谐和对时间规律的敏感性通常只在初级听觉皮层前外侧边界附近的一小群神经元中观察到，初级听觉皮层是先前确定的音调处理中心的位置。这些结果表明，虽然重复频率编码是听觉皮层加工的一个普遍组成部分，但周期性的神经关联仅限于听觉皮层中假设的音调加工中心内的一类特殊的音调选择神经元。
Bendor D, Wang X. Neural coding of periodicity in marmoset auditory cortex. J Neurophysiol 103: 1809-1822, 2010. First published February 10, 2010; doi: 10.1152/jn.00281.2009. Pitch, our perception of how high or low a sound is on a musical scale, crucially depends on a sound's periodicity. If an acoustic signal is temporally jittered so that it becomes aperiodic, the pitch will no longer be perceivable even though other acoustical features that normally covary with pitch are unchanged. Previous electrophysiological studies investigating pitch have typically used only periodic acoustic stimuli, and as such these studies cannot distinguish between a neural representation of pitch and an acoustical feature that only correlates with pitch. In this report, we examine in the auditory cortex of awake marmoset monkeys (Callithrix jacchus) the neural coding of a periodicity's repetition rate, an acoustic feature that covaries with pitch. We first examine if individual neurons show similar repetition rate tuning for different periodic acoustic signals. We next measure how sensitive these neural representations are to the temporal regularity of the acoustic signal. We find that neurons throughout auditory cortex covary their firing rate with the repetition rate of an acoustic signal. However, similar repetition rate tuning across acoustic stimuli and sensitivity to temporal regularity were generally only observed in a small group of neurons found near the anterolateral border of primary auditory cortex, the location of a previously identified putative pitch processing center. These results suggest that although the encoding of repetition rate is a general component of auditory cortical processing, the neural correlate of periodicity is confined to a special class of pitch-selective neurons within the putative pitch processing center of auditory cortex.