Dynamic and Task-Dependent Encoding of Speech and Voice by Phase Reorganization of Cortical Oscillations
Dynamic and Task-Dependent Encoding of Speech and Voice by Phase Reorganization of Cortical Oscillations
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DOI：
10.1523/jneurosci.3694-08.2009
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发表时间：
2009-02-11
影响因子：
5.3
通讯作者：
Formisano, Elia
中科院分区：
文献类型：
--
作者：
Bonte, Milene;Valente, Giancarlo;Formisano, Elia
语音和声音是人类交流的核心。对这些声音的皮质处理关键取决于行为需求。然而，实现这种自适应过程的神经计算机制仍然难以捉摸。在这里，我们研究了三个说话者(两个女性，一个男性)对自然语音(元音/a/，/i/，/u/)的脑电反应的任务依赖性重组，同时听者对元音或说话人身份执行一对一任务。我们发现，声诱发反应的动态变化和α频段(8-12赫兹)皮层振荡的相位模式密切地反映了沿任务相关维度对声音的提取和分析。元音分类导致与谁发音该元音无关地对相同元音例如/a/的响应的显著时间重排，而说话者分类导致对相同说话者(例如说话者1)的响应的显著时间重排，而与她/他发音的元音无关。这种对物理不同外部事件的神经元响应的瞬时和目标相关的重新排列为形成和处理听觉(语音)输入的抽象表示提供了健壮的皮质编码机制。
Speech and vocal sounds are at the core of human communication. Cortical processing of these sounds critically depends on behavioral demands. However, the neurocomputational mechanisms enabling this adaptive processing remain elusive. Here we examine the task-dependent reorganization of electroencephalographic responses to natural speech sounds ( vowels /a/, /i/, /u/) spoken by three speakers ( two female, one male) while listeners perform a one-back task on either vowel or speaker identity. We show that dynamic changes of sound-evoked responses and phase patterns of cortical oscillations in the alpha band (8-12 Hz) closely reflect the abstraction and analysis of the sounds along the task-relevant dimension. Vowel categorization leads to a significant temporal realignment of responses to the same vowel, e. g., /a/, independent of who pronounced this vowel, whereas speaker categorization leads to a significant temporal realignment of responses to the same speaker, e. g., speaker 1, independent of which vowel she/he pronounced. This transient and goal-dependent realignment of neuronal responses to physically different external events provides a robust cortical coding mechanism for forming and processing abstract representations of auditory ( speech) input.