Neuron-Specific Stimulus Masking Reveals Interference in Spike Timing at the Cortical Level
Neuron-Specific Stimulus Masking Reveals Interference in Spike Timing at the Cortical Level
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DOI：
10.1007/s10162-011-0292-1
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发表时间：
2012-02-01
影响因子：
2.4
通讯作者：
Billimoria, Cyrus P.
中科院分区：
文献类型：
--
作者：
Larson, Eric;Maddox, Ross K.;Billimoria, Cyrus P.
听觉系统能够在存在竞争掩蔽物（例如，其他声音或背景音乐）。尽管掩蔽刺激会破坏皮层水平的神经反应，但这种能力还是出现了。由于这种干扰效应的起源仍然是未知的，在这项研究中，我们的工作，以确定和量化的神经干扰效应，起源于由于掩蔽内和外的神经元感受野发生。我们记录单和多单位的听觉网站从外地L，听觉皮层同源的斑胸草雀。我们使用了一种新的方法，称为尖峰定时为基础的刺激过滤，使用每个神经元的测量响应，以创建一个个性化的刺激集。与以前的自适应实验方法相比，该方法通常集中在平均放电率上，该方法在感受野的计算中使用神经反应的完整模式，包括尖峰定时信息。当我们为每个神经元产生并呈现新的刺激来掩盖感受野内的区域时，我们发现神经反应中的时变信息被破坏，降低了神经辨别性能，降低了尖峰时间的可靠性和稀疏性。我们还发现，虽然从感受野以外的频率区域去除刺激能量不会显著影响许多站点的神经反应，但在这些频率区域中添加掩蔽物仍然可以对神经反应和辨别力产生显著影响，而平均放电率没有显著变化。这些发现表明，掩蔽物可以通过干扰神经元感受野内或感受野外的刺激时间信息来干扰神经反应。
The auditory system is capable of robust recognition of sounds in the presence of competing maskers (e.g., other voices or background music). This capability arises despite the fact that masking stimuli can disrupt neural responses at the cortical level. Since the origins of such interference effects remain unknown, in this study, we work to identify and quantify neural interference effects that originate due to masking occurring within and outside receptive fields of neurons. We record from single and multi-unit auditory sites from field L, the auditory cortex homologue in zebra finches. We use a novel method called spike timing-based stimulus filtering that uses the measured response of each neuron to create an individualized stimulus set. In contrast to previous adaptive experimental approaches, which have typically focused on the average firing rate, this method uses the complete pattern of neural responses, including spike timing information, in the calculation of the receptive field. When we generate and present novel stimuli for each neuron that mask the regions within the receptive field, we find that the time-varying information in the neural responses is disrupted, degrading neural discrimination performance and decreasing spike timing reliability and sparseness. We also find that, while removing stimulus energy from frequency regions outside the receptive field does not significantly affect neural responses for many sites, adding a masker in these frequency regions can nonetheless have a significant impact on neural responses and discriminability without a significant change in the average firing rate. These findings suggest that maskers can interfere with neural responses by disrupting stimulus timing information with power either within or outside the receptive fields of neurons.