Neural correlates of context-dependent perceptual enhancement in the inferior colliculus.
Neural correlates of context-dependent perceptual enhancement in the inferior colliculus.
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DOI：
10.1523/jneurosci.0277-10.2010
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发表时间：
2010-05-12
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影响因子：
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通讯作者：
Young ED
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文献类型：
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作者：
Nelson PC;Young ED
在某些情况下，先前的听觉刺激实际上会导致对后续声音的敏感度提高。这些现象中的许多似乎是在大脑中产生的，作为中央计算的反映。一个示例是宽带声音内的探测信号的鲁棒感知增强（或“弹出”），其起始时间相对于音调混合的其余部分延迟。在这里，我们表明，这种刺激的神经表征经历了一个戏剧性的转变，作为路径上升，从一个隐含的和分布式的外围代码明确促进单神经元反应的水平下丘（IC）的两个清醒和被动倾听的雌性绒猴（Callithrix jacchus）。IC响应的许多关键特征直接平行于增强的心理物理测量，包括对探头周围的频谱陷波宽度、复合物的总体水平和前一声音的持续时间（称为条件）的依赖。神经探测阈值的探头和没有空调也定性协议与类似的心理声学措施。在空调的响应特性预测随后的探测响应的增强或抑制：建立响应与增强，而适应空调响应更有可能导致抑制。这些数据可以在很大程度上解释了一个现象学的计算模型，使用动态（适应）抑制作为一个必要的成分，在生成的神经增强。
In certain situations, preceding auditory stimulation can actually result in heightened sensitivity to subsequent sounds. Many of these phenomena appear to be generated in the brain as reflections of central computations. One example is the robust perceptual enhancement (or “pop out”) of a probe signal within a broad-band sound whose onset time is delayed relative to the remainder of a mixture of tones. Here we show that the neural representation of such stimuli undergoes a dramatic transformation as the pathway is ascended, from an implicit and distributed peripheral code to explicitly facilitated single-neuron responses at the level of the inferior colliculus (IC) of two awake and passively listening female marmoset monkeys (callithrix jacchus). Many key features of the IC responses directly parallel psychophysical measures of enhancement, including the dependence on the width of a spectral notch surrounding the probe, the overall level of the complex, and the duration of the preceding sound (referred to as the conditioner). Neural detection thresholds for the probe with and without the conditioner were also in qualitative agreement with analogous psychoacoustic measures. Response characteristics during the conditioners were predictive of the enhancement or suppression of the ensuing probe response: build-up responses were associated with enhancement while adapting conditioner responses were more likely to result in suppression. These data can be largely explained by a phenomenological computational model using dynamic (adapting) inhibition as a necessary ingredient in the generation of neural enhancement.