Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands.
University of Amsterdam, Amsterdam, the Netherlands.
Neuroimage. 2020 Dec;223:117319. doi: 10.1016/j.neuroimage.2020.117319. Epub 2020 Aug 31.
There is increasing evidence that the hippocampus is involved in language production and verbal communication, although little is known about its possible role. According to one view, hippocampus contributes semantic memory to spoken language. Alternatively, hippocampus is involved in the processing the (mis)match between expected sensory consequences of speaking and the perceived speech feedback. In the current study, we re-analysed functional magnetic resonance (fMRI) data of two overt picture-naming studies to test whether hippocampus is involved in speech production and, if so, whether the results can distinguish between a "pure memory" versus a "prediction" account of hippocampal involvement. In both studies, participants overtly named pictures during scanning while hearing their own speech feedback unimpededly or impaired by a superimposed noise mask. Results showed decreased hippocampal activity when speech feedback was impaired, compared to when feedback was unimpeded. Further, we found increased functional coupling between auditory cortex and hippocampus during unimpeded speech feedback, compared to impaired feedback. Finally, we found significant functional coupling between a hippocampal/supplementary motor area (SMA) interaction term and auditory cortex, anterior cingulate cortex and cerebellum during overt picture naming, but not during listening to one's own pre-recorded voice. These findings indicate that hippocampus plays a role in speech production that is in accordance with a "prediction" view of hippocampal functioning.
越来越多的证据表明，海马体参与语言产生和口头交流，尽管其可能的作用知之甚少。根据一种观点，海马体为口语提供语义记忆。或者，海马体参与处理说话时预期感觉后果与感知到的语音反馈之间的（不）匹配。在当前的研究中，我们重新分析了两项显性图片命名研究的功能磁共振（fMRI）数据，以测试海马体是否参与言语产生，如果是，结果是否可以区分海马体参与的“纯记忆”与“预测”解释。在这两项研究中，参与者在扫描过程中大声说出图片的名称，同时不受干扰或受到叠加噪声掩蔽的干扰地听到自己的语音反馈。结果表明，与反馈不受干扰时相比，语音反馈受到干扰时海马体活动减少。此外，我们发现，与反馈受到干扰时相比，反馈不受干扰时听觉皮层与海马体之间的功能耦合增加。最后，我们发现，在显性图片命名期间，海马体/辅助运动区（SMA）交互项与听觉皮层、前扣带皮层和小脑之间存在显著的功能耦合，但在聆听自己的预录语音时则不存在。这些发现表明，海马体在言语产生中发挥作用，这与海马体功能的“预测”观点一致。
