Hullett Patrick W, Hamilton Liberty S, Mesgarani Nima, Schreiner Christoph E, Chang Edward F
University of California Berkeley and San Francisco Joint Graduate Group in Bioengineering, Center for Integrative Neuroscience, Department of Otolaryngology-Head and Neck Surgery, and.
Center for Integrative Neuroscience, Department of Neurological Surgery, School of Medicine, University of California, San Francisco, San Francisco, California 94158.
J Neurosci. 2016 Feb 10;36(6):2014-26. doi: 10.1523/JNEUROSCI.1779-15.2016.
The human superior temporal gyrus (STG) is critical for speech perception, yet the organization of spectrotemporal processing of speech within the STG is not well understood. Here, to characterize the spatial organization of spectrotemporal processing of speech across human STG, we use high-density cortical surface field potential recordings while participants listened to natural continuous speech. While synthetic broad-band stimuli did not yield sustained activation of the STG, spectrotemporal receptive fields could be reconstructed from vigorous responses to speech stimuli. We find that the human STG displays a robust anterior-posterior spatial distribution of spectrotemporal tuning in which the posterior STG is tuned for temporally fast varying speech sounds that have relatively constant energy across the frequency axis (low spectral modulation) while the anterior STG is tuned for temporally slow varying speech sounds that have a high degree of spectral variation across the frequency axis (high spectral modulation). This work illustrates organization of spectrotemporal processing in the human STG, and illuminates processing of ethologically relevant speech signals in a region of the brain specialized for speech perception.
Considerable evidence has implicated the human superior temporal gyrus (STG) in speech processing. However, the gross organization of spectrotemporal processing of speech within the STG is not well characterized. Here we use natural speech stimuli and advanced receptive field characterization methods to show that spectrotemporal features within speech are well organized along the posterior-to-anterior axis of the human STG. These findings demonstrate robust functional organization based on spectrotemporal modulation content, and illustrate that much of the encoded information in the STG represents the physical acoustic properties of speech stimuli.
人类颞上回（STG）对语音感知至关重要，但STG内语音的频谱-时间处理组织尚不清楚。在这里，为了描述人类STG中语音频谱-时间处理的空间组织，我们在参与者听自然连续语音时使用高密度皮质表面场电位记录。虽然合成宽带刺激并未引起STG的持续激活，但可以从对语音刺激的强烈反应中重建频谱-时间感受野。我们发现，人类STG在频谱-时间调谐上呈现出强大的前后空间分布，其中后颞上回针对频率轴上能量相对恒定（低频谱调制）的时间快速变化的语音进行调谐，而前颞上回针对频率轴上具有高度频谱变化（高频谱调制）的时间缓慢变化的语音进行调谐。这项工作阐明了人类STG中频谱-时间处理的组织，并揭示了在专门用于语音感知的大脑区域中对行为学相关语音信号的处理。
大量证据表明人类颞上回（STG）参与语音处理。然而，STG内语音频谱-时间处理的总体组织尚未得到很好的描述。在这里，我们使用自然语音刺激和先进的感受野表征方法来表明，语音中的频谱-时间特征沿人类STG的后-前轴组织良好。这些发现证明了基于频谱-时间调制内容的强大功能组织，并表明STG中编码的许多信息代表了语音刺激的物理声学特性。
