The unconscious integration of vocal and facial cues during speech perception facilitates face-to-face communication. Recent studies have provided substantial behavioural evidence concerning impairments in audiovisual (AV) speech perception in schizophrenia. However, the specific neurophysiological mechanism underlying these deficits remains unknown. Here, we investigated activities and connectivities centered on the auditory cortex during AV speech perception in schizophrenia. Using magnetoencephalography, we recorded and analysed event-related fields in response to auditory (A: voice), visual (V: face) and AV (voice–face) stimuli in 23 schizophrenia patients (13 males) and 22 healthy controls (13 males). The functional connectivity associated with the subadditive response to AV stimulus (i.e., [AV] < [A] + [V]) was also compared between the two groups. Within the healthy control group, [AV] activity was smaller than the sum of [A] and [V] at latencies of approximately 100 ms in the posterior ramus of the lateral sulcus in only the left hemisphere, demonstrating a subadditive N1m effect. Conversely, the schizophrenia group did not show such a subadditive response. Furthermore, weaker functional connectivity from the posterior ramus of the lateral sulcus of the left hemisphere to the fusiform gyrus of the right hemisphere was observed in schizophrenia. Notably, this weakened connectivity was associated with the severity of negative symptoms. These results demonstrate abnormalities in connectivity between speech- and face-related cortical areas in schizophrenia. This aberrant subadditive response and connectivity deficits for integrating speech and facial information may be the neural basis of social communication dysfunctions in schizophrenia.

中文翻译：

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精神分裂症视听言语感知过程中的异常连接和激活

在言语感知过程中，声音和面部线索的无意识整合促进了面对面的交流。最近的研究提供了关于精神分裂症视听（AV）言语感知障碍的大量行为证据。然而，这些缺陷背后的具体神经生理学机制仍然未知。在这里，我们研究了精神分裂症患者 AV 言语感知过程中以听觉皮层为中心的活动和连接。使用脑磁图，我们记录并分析了 23 名精神分裂症患者（13 名男性）和 22 名健康对照者（13 名男性）对听觉（A：声音）、视觉（V：面部）和 AV（声音-面部）刺激的事件相关场的反应。 ）。两组之间还比较了与 AV 刺激的次加性反应（即 [AV] < [A] + [V]）相关的功能连接。在健康对照组中，仅在左半球的外侧沟后支中，在潜伏期约 100 ms 时，[AV] 活性小于 [A] 和 [V] 的总和，这表明存在次加性 N1m 效应。相反，精神分裂症组没有表现出这种亚加性反应。此外，在精神分裂症中观察到从左半球外侧沟后支到右半球梭状回的功能连接较弱。值得注意的是，这种减弱的连通性与阴性症状的严重程度有关。这些结果表明精神分裂症患者的言语和面部相关皮层区域之间的连接异常。这种异常的亚加性反应和整合语音和面部信息的连接性缺陷可能是精神分裂症社交沟通功能障碍的神经基础。