Department of Speech-Language Pathology, University of Toronto, Toronto, Ontario, Canada.
Neuroimage. 2011 Feb 14;54(4):2994-3003. doi: 10.1016/j.neuroimage.2010.11.026. Epub 2010 Nov 21.
Auditory responses to speech sounds that are self-initiated are suppressed compared to responses to the same speech sounds during passive listening. This phenomenon is referred to as speech-induced suppression, a potentially important feedback-mediated speech-motor control process. In an earlier study, we found that both adults who do and do not stutter demonstrated a reduced amplitude of the auditory M50 and M100 responses to speech during active production relative to passive listening. It is unknown if auditory responses to self-initiated speech-motor acts are suppressed in children or if the phenomenon differs between children who do and do not stutter. As stuttering is a developmental speech disorder, examining speech-induced suppression in children may identify possible neural differences underlying stuttering close to its time of onset. We used magnetoencephalography to determine the presence of speech-induced suppression in children and to characterize the properties of speech-induced suppression in children who stutter. We examined the auditory M50 as this was the earliest robust response reproducible across our child participants and the most likely to reflect a motor-to-auditory relation. Both children who do and do not stutter demonstrated speech-induced suppression of the auditory M50. However, children who stutter had a delayed auditory M50 peak latency to vowel sounds compared to children who do not stutter indicating a possible deficiency in their ability to efficiently integrate auditory speech information for the purpose of establishing neural representations of speech sounds.
与被动聆听时相比，自我发起的语音声音的听觉反应会受到抑制。这种现象被称为语音诱导抑制，是一种潜在的重要反馈介导的言语运动控制过程。在早期的一项研究中，我们发现，无论是口吃者还是非口吃者，在主动产生语音时，其听觉 M50 和 M100 反应的幅度相对于被动聆听时都会减小。目前尚不清楚自我发起的言语运动行为的听觉反应是否会在儿童中受到抑制，或者口吃儿童和非口吃儿童之间是否存在差异。由于口吃是一种发育性言语障碍，因此在儿童中检查语音诱导抑制可能有助于确定口吃发生时潜在的神经差异。我们使用脑磁图来确定儿童是否存在语音诱导抑制，并描述口吃儿童的语音诱导抑制的特性。我们检查了听觉 M50，因为这是我们的儿童参与者中最早且可重复出现的稳健反应，最有可能反映出运动与听觉之间的关系。无论是口吃者还是非口吃者，其听觉 M50 都表现出了语音诱导抑制。然而，与非口吃者相比，口吃者的元音听觉 M50 峰值潜伏期延迟，这表明他们可能在有效整合听觉言语信息以建立言语声音的神经表示方面存在能力缺陷。
