Competing sound sources reveal spatial effects in cortical processing.
Competing sound sources reveal spatial effects in cortical processing.
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DOI：
10.1371/journal.pbio.1001319
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发表时间：
2012
期刊：
影响因子：
9.8
通讯作者：
Sen K
中科院分区：
文献类型：
--
作者：
Maddox RK;Billimoria CP;Perrone BP;Shinn-Cunningham BG;Sen K
鸟类听觉前脑的神经元对两个竞争源的空间结构表现出很强的敏感性，即使对任何单个源只有很弱的空间依赖性。为什么听觉皮层的空间调谐很弱，尽管在自然环境中位置对物体识别很重要？这个问题一直困扰着神经科学家，他们专注于将生理结果与听觉感知联系起来。在这里，我们表明，同时，竞争声源的空间位置显着影响如何以及神经尖峰列车记录斑胸草雀场L（哺乳动物初级听觉皮层的模拟）编码源身份。我们发现，安静时鸟鸣声的位置对歌曲神经编码的保真度影响不大。然而，当歌曲沿着掩蔽音时，空间效果明显。对于每个空间配置，一个子集的神经元编码的歌曲身份比其他人更强大。因此，来自不同位置的竞争源支配不同神经亚群的反应，有助于将神经反应分离成独立的表征。这些结果有助于阐明皮层处理如何利用空间信息提供一个基板选择性空间听觉注意。当一个听众同时面对许多声源时，当一个特定的声源来自不同的空间位置时，比其他竞争声源更容易理解。然而，以往对听觉皮层的研究普遍发现，在对单一声源的反应中，皮层并没有对空间位置的精确表征，这使得空间位置的这种效应难以理解。在这里，我们提出了斑马雀与两个同时的声音（鸟鸣目标和噪声掩蔽的声音）从不同的空间位置和记录的神经反应在字段L，这是类似于哺乳动物的初级听觉皮层。当目标声音单独呈现时，声源的位置对基于L场神经活动识别目标歌曲的能力几乎没有影响。然而，当目标呈现掩蔽声时，两个源的位置强烈影响神经辨别性能。此外，不同的神经元亚群优先编码目标或掩蔽，提供了一个潜在的基板空间选择性注意。因此，即使位置在皮层神经元中没有很好地编码，空间信息也强烈地调节皮层反应。
Neurons in the avian auditory forebrain show strong sensitivity to the spatial configuration of two competing sources, even though there is only weak spatial dependence for any single source. Why is spatial tuning in auditory cortex weak, even though location is important to object recognition in natural settings? This question continues to vex neuroscientists focused on linking physiological results to auditory perception. Here we show that the spatial locations of simultaneous, competing sound sources dramatically influence how well neural spike trains recorded from the zebra finch field L (an analog of mammalian primary auditory cortex) encode source identity. We find that the location of a birdsong played in quiet has little effect on the fidelity of the neural encoding of the song. However, when the song is presented along with a masker, spatial effects are pronounced. For each spatial configuration, a subset of neurons encodes song identity more robustly than others. As a result, competing sources from different locations dominate responses of different neural subpopulations, helping to separate neural responses into independent representations. These results help elucidate how cortical processing exploits spatial information to provide a substrate for selective spatial auditory attention. When a listener is presented with many sound sources at once, it is easier to understand a particular source when it comes from a different spatial location than the other competing sources. However, past studies of auditory cortex generally find that in response to a single sound source, there is not a precise representation of spatial location in the cortex, which makes this effect of spatial location hard to understand. Here, we presented zebra finches with two simultaneous sounds (a birdsong target and a noise masking sound) from distinct spatial locations and recorded neural responses in field L, which is analogous to primary auditory cortex in mammals. When the target sound was presented by itself, the location of the source had little effect on the ability to identify the target song based on neural activity in field L. However, when the target was presented with a masker sound, the location of both sources strongly affected neural discrimination performance. Moreover, different subpopulations of neurons preferentially encoded either target or masker, providing a potential substrate for spatial selective attention. Thus, even though location is not well coded in cortical neurons, spatial information strongly modulates cortical responses.
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影响因子：
2.4
作者：
Best, V;Ozmeral, E;Shinn-Cunningham, BG
通讯作者：
Shinn-Cunningham, BG
影响因子：
2.5
作者：
IMIG, TJ;IRONS, WA;SAMSON, FR
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作者：
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影响因子：
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作者：
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DOI：
10.1007/s10162-011-0292-1
发表时间：
2012-02-01
影响因子：
2.4
作者：
Larson, Eric;Maddox, Ross K.;Billimoria, Cyrus P.
通讯作者：
Billimoria, Cyrus P.