ATR Computational Neuroscience Laboratories, Kyoto, Japan.
Neuroimage. 2010 Jun;51(2):844-58. doi: 10.1016/j.neuroimage.2010.02.027. Epub 2010 Feb 22.
Articulatory goals have long been proposed to mediate perception. Examples include direct realist and constructivist (analysis by synthesis) theories of speech perception. Although the activity in brain regions involved with action production has been shown to be present during action observation (Mirror Neuron System), the relationship of this activity to perceptual performance has not been clearly demonstrated at the event level. To this end we used functional magnetic resonance imaging fMRI and magnetoencephalography MEG to measure brain activity for correct and incorrect trials of an auditory phonetic identification in noise task. FMRI analysis revealed activity in the premotor cortex including the neighboring frontal opercular part of Broca's area (PMC/Broca's) for both perception and production tasks involving the same phonetic stimuli (potential mirror system site) that was significantly greater for correct over incorrect perceptual identification trials. Time-frequency analysis of single trials conducted over MEG current localized to PMC/Broca's using a hierarchical variational Bayesian source analysis technique revealed significantly greater event-related synchronization ERS and desynchronization ERD for correct over incorrect trials in the alpha, beta, and gamma frequency range prior to and after stimulus presentation. Together, these fMRI and MEG results are consistent with the hypothesis that articulatory processes serve to facilitate perceptual performance, while further dispelling concerns that activity found in ventral PMC/Broca's (mirror system) is merely a product of covert production of the perceived action. The finding of performance predictive activity prior to stimulus onset as well as activity related to task difficulty instead of information available in stimulation are consistent with constructivist and contrary to direct realist theories of perception.
发音目标长期以来被认为是感知的中介。例如，语音感知的直接现实主义和建构主义（分析综合）理论。尽管已经证明，在观察动作时，与动作产生相关的大脑区域的活动是存在的（镜像神经元系统），但这种活动与感知表现之间的关系在事件水平上并没有得到明确证明。为此，我们使用功能磁共振成像（fMRI）和脑磁图（MEG）来测量听觉语音识别任务中正确和错误试次的大脑活动。fMRI 分析显示，运动前皮层（PMC/布洛卡区的相邻额回部分）在感知和产生任务中都有活动，涉及到相同的语音刺激（潜在的镜像系统部位），对于正确的感知识别试次，其活动明显大于错误的试次。使用分层变分贝叶斯源分析技术，对 MEG 中单个试次的时频分析显示，在刺激呈现前后的 alpha、beta 和 gamma 频率范围内，正确试次的事件相关同步（ERS）和去同步（ERD）明显大于错误试次。fMRI 和 MEG 的结果一致表明，发音过程有助于提高感知表现，同时进一步消除了对腹侧 PMC/布洛卡区（镜像系统）活动仅仅是感知动作的隐蔽产生的产物的担忧。在刺激呈现之前，以及与任务难度相关的活动而不是与刺激中可用信息相关的活动，与建构主义一致，与感知的直接现实主义理论相反。
