Neurology Department, New York University, New York, United States.
Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands.
Elife. 2024 Sep 10;13:RP94198. doi: 10.7554/eLife.94198.
Across the animal kingdom, neural responses in the auditory cortex are suppressed during vocalization, and humans are no exception. A common hypothesis is that suppression increases sensitivity to auditory feedback, enabling the detection of vocalization errors. This hypothesis has been previously confirmed in non-human primates, however a direct link between auditory suppression and sensitivity in human speech monitoring remains elusive. To address this issue, we obtained intracranial electroencephalography (iEEG) recordings from 35 neurosurgical participants during speech production. We first characterized the detailed topography of auditory suppression, which varied across superior temporal gyrus (STG). Next, we performed a delayed auditory feedback (DAF) task to determine whether the suppressed sites were also sensitive to auditory feedback alterations. Indeed, overlapping sites showed enhanced responses to feedback, indicating sensitivity. Importantly, there was a strong correlation between the degree of auditory suppression and feedback sensitivity, suggesting suppression might be a key mechanism that underlies speech monitoring. Further, we found that when participants produced speech with simultaneous auditory feedback, posterior STG was selectively activated if participants were engaged in a DAF paradigm, suggesting that increased attentional load can modulate auditory feedback sensitivity.
在整个动物王国中，听觉皮层的神经反应在发声时会受到抑制，人类也不例外。一个常见的假设是，抑制作用会提高对听觉反馈的敏感性，从而能够检测到发声错误。这一假设在非人类灵长类动物中得到了证实，然而，听觉抑制与人类言语监测敏感性之间的直接联系仍然难以捉摸。为了解决这个问题，我们在 35 名接受神经外科手术的参与者进行言语产生时获得了颅内脑电图 (iEEG) 记录。我们首先描述了听觉抑制的详细空间分布，其在颞上回 (STG) 中有所不同。接下来，我们进行了延迟听觉反馈 (DAF) 任务，以确定被抑制的部位是否也对听觉反馈变化敏感。事实上，重叠部位对反馈的反应增强，表明具有敏感性。重要的是，听觉抑制的程度与反馈敏感性之间存在很强的相关性，这表明抑制可能是言语监测的关键机制。此外，我们发现当参与者在产生言语的同时接受听觉反馈时，如果参与者参与 DAF 范式，后颞上回会被选择性激活，这表明注意力负荷的增加可以调节听觉反馈敏感性。
