Northwestern University, Evanston, IL, USA.
J Cogn Neurosci. 2011 May;23(5):1205-17. doi: 10.1162/jocn.2010.21447. Epub 2010 Feb 10.
The neural responses to sensory consequences of a self-produced motor act are suppressed compared with those in response to a similar but externally generated stimulus. Previous studies in the somatosensory and auditory systems have shown that the motor-induced suppression of the sensory mechanisms is sensitive to delays between the motor act and the onset of the stimulus. The present study investigated time-dependent neural processing of auditory feedback in response to self-produced vocalizations. ERPs were recorded in response to normal and pitch-shifted voice auditory feedback during active vocalization and passive listening to the playback of the same vocalizations. The pitch-shifted stimulus was delivered to the subjects' auditory feedback after a randomly chosen time delay between the vocal onset and the stimulus presentation. Results showed that the neural responses to delayed feedback perturbations were significantly larger than those in response to the pitch-shifted stimulus occurring at vocal onset. Active vocalization was shown to enhance neural responsiveness to feedback alterations only for nonzero delays compared with passive listening to the playback. These findings indicated that the neural mechanisms of auditory feedback processing are sensitive to timing between the vocal motor commands and the incoming auditory feedback. Time-dependent neural processing of auditory feedback may be an important feature of the audio-vocal integration system that helps to improve the feedback-based monitoring and control of voice structure through vocal error detection and correction.
与对外界产生的类似刺激的反应相比，自身产生的运动行为的感官后果引起的神经反应受到抑制。先前在体感和听觉系统中的研究表明，运动引起的对感觉机制的抑制对运动行为和刺激开始之间的延迟很敏感。本研究调查了对自身产生的发声的听觉反馈的随时间变化的神经处理。在主动发声和被动聆听相同发声的回放时，记录了对正常和音高变换的语音听觉反馈的 ERP。在发声开始和刺激呈现之间的随机选择的时间延迟之后，将音高变换的刺激传递给受试者的听觉反馈。结果表明，与在发声开始时发生的音高变换刺激相比，对延迟的反馈干扰的神经反应明显更大。与被动聆听回放相比，主动发声仅在非零延迟时增强了对反馈变化的神经反应能力。这些发现表明，听觉反馈处理的神经机制对发声运动指令和传入听觉反馈之间的时间敏感。听觉反馈的随时间变化的神经处理可能是音频-声音整合系统的一个重要特征，有助于通过声音错误检测和校正来提高基于反馈的声音结构的监控和控制。
