Department of Neurosurgery, University of Iowa, Iowa City, Iowa, United States of America.
PLoS One. 2011 Mar 3;6(3):e14744. doi: 10.1371/journal.pone.0014744.
During speaking, auditory feedback is used to adjust vocalizations. The brain systems mediating this integrative ability have been investigated using a wide range of experimental strategies. In this report we examined how vocalization alters speech-sound processing within auditory cortex by directly recording evoked responses to vocalizations and playback stimuli using intracranial electrodes implanted in neurosurgery patients. Several new findings resulted from these high-resolution invasive recordings in human subjects. Suppressive effects of vocalization were found to occur only within circumscribed areas of auditory cortex. In addition, at a smaller number of sites, the opposite pattern was seen; cortical responses were enhanced during vocalization. This increase in activity was reflected in high gamma power changes, but was not evident in the averaged evoked potential waveforms. These new findings support forward models for vocal control in which efference copies of premotor cortex activity modulate sub-regions of auditory cortex.
在说话过程中，听觉反馈用于调整发声。使用广泛的实验策略研究了介导这种综合能力的大脑系统。在本报告中，我们通过使用植入神经外科患者的颅内电极直接记录对发声和回放刺激的诱发反应，检查了发声如何改变听觉皮层内的语音处理。这些来自人类受试者的高分辨率侵入性记录产生了一些新的发现。发现发声的抑制作用仅发生在听觉皮层的特定区域内。此外，在少数部位观察到相反的模式；发声时皮质反应增强。这种活动增加反映在高伽马功率变化中，但在平均诱发电位波形中并不明显。这些新发现支持发声控制的前馈模型，其中运动前皮层活动的传出副本调节听觉皮层的子区域。
