A Spatial Map of Onset and Sustained Responses to Speech in the Human Superior Temporal Gyrus
A Spatial Map of Onset and Sustained Responses to Speech in the Human Superior Temporal Gyrus
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DOI：
10.1016/j.cub.2018.04.033
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发表时间：
2018-06-18
期刊：
影响因子：
9.2
通讯作者：
Chang, Edward F.
中科院分区：
文献类型：
--
作者：
Hamilton, Liberty S.;Edwards, Erik;Chang, Edward F.
为了从语音中获得意义，我们必须从输入的语音信号中提取多个维度的并发信息。也就是说，与处理语音特征同样重要的是检测声学线索，这些线索为我们听到的信息提供了结构和上下文。大脑如何组织这些信息是未知的。使用数据驱动的计算方法对高密度颅内录音从27名人类参与者，我们揭示了功能的区别，在后上级颞回的语音神经反应，根据无论是发病或持续的反应配置文件。虽然类似的反应类型已被观察到整个听觉系统，我们发现了新的证据，一个主要的空间parcellation中，一个独特的尾侧区检测声学发作和嘴部环绕区持续，相对延迟的反应正在进行的语音刺激。虽然在自然语音感知期间基本上使用后发作和前持续响应，但是它们不限于语音刺激，并且甚至对于反转或频谱旋转的语音也可以看到。单电极编码的语音特征在每个区域取决于是否发生在句子开始的声音，这表明联合编码的语音特征和他们的时间背景。尾侧区的起始反应可以准确地解码句子和短语起始边界，为检测语音和其他自然声音中的时间标志提供了潜在的重要内部机制。这些发现表明，起始和持续的反应不仅定义了高级听觉皮层的基本空间组织，而且对语音信息在皮层中的解析方式也有直接的影响。
To derive meaning from speech, we must extract multiple dimensions of concurrent information from incoming speech signals. That is, equally important to processing phonetic features is the detection of acoustic cues that give structure and context to the information we hear. How the brain organizes this information is unknown. Using data-driven computational methods on high-density intracranial recordings from 27 human participants, we reveal the functional distinction of neural responses to speech in the posterior superior temporal gyrus according to either onset or sustained response profiles. Though similar response types have been observed throughout the auditory system, we found novel evidence for a major spatial parcellation in which a distinct caudal zone detects acoustic onsets and a rostral-surround zone shows sustained, relatively delayed responses to ongoing speech stimuli. While posterior onset and anterior sustained responses are used substantially during natural speech perception, they are not limited to speech stimuli and are seen even for reversed or spectrally rotated speech. Single-electrode encoding of phonetic features in each zone depended upon whether the sound occurred at sentence onset, suggesting joint encoding of phonetic features and their temporal context. Onset responses in the caudal zone could accurately decode sentence and phrase onset boundaries, providing a potentially important internal mechanism for detecting temporal landmarks in speech and other natural sounds. These findings suggest that onset and sustained responses not only define the basic spatial organization of high-order auditory cortex but also have direct implications for how speech information is parsed in the cortex.