The Orofacial Somatosensory System Is Modulated During Speech Planning and Production.
The Orofacial Somatosensory System Is Modulated During Speech Planning and Production.
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口面部体感系统在言语规划和产生过程中受到调节。
DOI：
10.1044/2020_jslhr-19-00318
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Daliri,Ayoub
中科院分区：
文献类型：
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作者：
McGuffin,BriannaJ;Liss,JulieM;Daliri,Ayoub
在我们之前的研究中，我们发现大脑对听觉系统进行调节，并且这种调节始于言语计划。然而，目前尚不清楚大脑是否使用类似的机制来调节口面部体感系统。在这里，我们开发了一种新的行为范式来(a)检查体感系统在言语计划过程中是否被调节，(b)确定在言语计划和言语产生过程中体感调节的时间过程。方法采用电流刺激下唇诱导体感的实验方法，共20例。在第一个实验中，我们使用阶梯法（一上四下）来确定每个参与者在休息时的感知阈值（即参与者在85%的试验中检测到的刺激）。在第二个实验中，我们估计了每个参与者在说话前和控制条件（默读）的不同时间点对电刺激的检测比率（其大小相当于他们的感知阈值）。结果静默阅读状态下的整体检测率相对于静止状态下的检测率保持不变。在言语开始前536 ms左右，说话条件下的检测率与默读条件下的检测率相似；然而，说话状态下的检测率逐渐开始下降，并在说话前58 ms达到最低水平。总之，我们提供了令人信服的行为证据，表明当言语运动系统准备言语运动时，它也以一种时间特异性的方式调节口面体感系统。
PurposeIn our previous studies, we showed that the brain modulates the auditory system, and the modulation starts during speech planning. However, it remained unknown whether the brain uses similar mechanisms to modulate the orofacial somatosensory system. Here, we developed a novel behavioral paradigm to (a) examine whether the somatosensory system is modulated during speech planning and (b) determine the somatosensory modulation's time course during planning and production.MethodParticipants (N= 20) completed two experiments in which we applied electrical current stimulation to the lower lip to induce somatosensory sensation. In the first experiment, we used a staircase method (one-up, four-down) to determine each participant's perceptual threshold at rest (i.e., the stimulus that the participant detected on 85% of trials). In the second experiment, we estimated each participant's detection ratio of electrical stimuli (with a magnitude equivalent of their perceptual threshold) delivered at various time points before speaking and during a control condition (silent reading).ResultsWe found that the overall detection ratio in the silent reading condition remained unchanged relative to the detection ratio at rest. Approximately 536 ms before speech onset, the detection ratio in the speaking condition was similar to that in the silent reading condition; however, the detection ratio in the speaking condition gradually started to decrease and reached its lowest level at 58 ms before speech onset.ConclusionsOverall, we provided compelling behavioral evidence that, as the speech motor system prepares speech movements, it also modulates the orofacial somatosensory system in a temporally specific manner.