Sensitivity to an Illusion of Sound Location in Human Auditory Cortex.
Sensitivity to an Illusion of Sound Location in Human Auditory Cortex.
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DOI：
10.3389/fnsys.2017.00035
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发表时间：
2017
影响因子：
3
通讯作者：
Stecker GC
中科院分区：
文献类型：
--
作者：
Higgins NC;McLaughlin SA;Da Costa S;Stecker GC
人类听众在确定声音位置时，会将更大的权重放在声音的开头，而不是中间或结尾，从而产生一种被称为弗朗森效应的听觉错觉。在这里，我们利用这种效应来测试人类听觉皮层（AC）是否代表声音的物理与感知空间特征。我们使用功能性磁共振成像（fMRI）来测量AC响应的声音，不同的感知位置，由于耳间水平差（ILD）适用于声音发作或完整的声音持续时间。AC的血流动力学反应分析显示，在完全提示（真实）和仅发作（虚幻）的偏侧刺激中对ILD敏感。分类分析显示，对仅发作ILD的敏感性存在地区差异，与原发性AC相比，在后房中观察到更好的分类。也就是说，将ILD限制在声音开始时（这会改变空间线索的物理性质，但不会改变感知性质），并不能消除皮层对该线索的敏感性。这些结果表明，听觉空间的感知表征出现或在高阶AC区域中被细化，支持在嘈杂或混响环境中对听觉空间的稳定感知，并形成诸如弗朗森效应的错觉的基础。
Human listeners place greater weight on the beginning of a sound compared to the middle or end when determining sound location, creating an auditory illusion known as the Franssen effect. Here, we exploited that effect to test whether human auditory cortex (AC) represents the physical vs. perceived spatial features of a sound. We used functional magnetic resonance imaging (fMRI) to measure AC responses to sounds that varied in perceived location due to interaural level differences (ILD) applied to sound onsets or to the full sound duration. Analysis of hemodynamic responses in AC revealed sensitivity to ILD in both full-cue (veridical) and onset-only (illusory) lateralized stimuli. Classification analysis revealed regional differences in the sensitivity to onset-only ILDs, where better classification was observed in posterior compared to primary AC. That is, restricting the ILD to sound onset—which alters the physical but not the perceptual nature of the spatial cue—did not eliminate cortical sensitivity to that cue. These results suggest that perceptual representations of auditory space emerge or are refined in higher-order AC regions, supporting the stable perception of auditory space in noisy or reverberant environments and forming the basis of illusions such as the Franssen effect.