Department of Psychology, University of Milano-Bicocca, P.za Ateneo Nuovo 1, Milano, Italy.
Neuroimage. 2013 Aug 1;76:24-32. doi: 10.1016/j.neuroimage.2013.03.020. Epub 2013 Mar 21.
Neuroimaging and electrophysiological studies have shown the involvement of a fronto-temporo-occipital network in face processing, but the functional relation among these areas remains unclear. We used transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) to explore the local and global cortical excitability at rest and during two different face processing behavioral tasks. Single-pulse TMS was delivered (100 ms after face stimulus onset) over the right medial prefrontal cortex (mPFC) during a face identity or a face expression matching task, while continuous EEG was recorded using a 60-channel TMS-compatible amplifier. We examined TMS effects on the occipital face-specific ERP component and compared TMS-evoked potentials (TEPs) recorded during task performance and a passive point fixation control task. TMS reduced the P1-N1 component recorded at the occipital electrodes. Moreover, performing face tasks significantly modulated TEPs recorded at the occipital and temporal electrodes within the first 30 ms after right mPFC stimulation, with a specific increase of temporal TEPs in the right hemisphere for the facial expression task. Furthermore, in order to test the site-specificity of the reported effects, TMS was applied over the right premotor cortex (PMC) as a control site using the same experimental paradigm. Results showed that TMS over the right PMC did not affect ERP components in posterior regions during the face tasks and TEP amplitude did not change between task and no task condition, either at fronto-central electrodes near the stimulation or at temporal and occipital electrodes. These findings support the notion that the prefrontal cortex exerts a very early influence over the occipital cortex during face processing tasks and that excitability across right fronto-temporal cortical regions is significantly modulated during explicit facial expression processing.
神经影像学和电生理学研究表明，额颞顶枕网络参与了面孔处理，但这些区域之间的功能关系尚不清楚。我们使用经颅磁刺激结合脑电图（TMS-EEG）来探索静息状态和两种不同的面孔处理行为任务期间局部和全局皮质兴奋性。在面孔身份或面孔表情匹配任务期间，在右侧内侧前额叶皮层（mPFC）上给予单脉冲 TMS（在面孔刺激开始后 100 毫秒），同时使用 60 通道 TMS 兼容放大器记录连续 EEG。我们检查了 TMS 对枕部面孔特异性 ERP 成分的影响，并比较了在任务执行期间和被动点固定控制任务期间记录的 TMS 诱发电位（TEP）。TMS 降低了在枕部电极记录的 P1-N1 成分。此外，执行面孔任务显着调节了在右侧 mPFC 刺激后最初 30 毫秒内在枕部和颞部电极记录的 TEP，在面孔表情任务中右半球的颞部 TEP 特异性增加。此外，为了测试报告的效应的特异性，使用相同的实验范式，将 TMS 施加于右侧运动前皮层（PMC）作为对照部位。结果表明，TMS 施加于右侧 PMC 不会对面孔任务期间的后部区域的 ERP 成分产生影响，并且在任务和无任务条件之间，在刺激附近的额-中央电极或颞部和枕部电极处，TEP 幅度都没有变化。这些发现支持了这样的观点，即前额叶皮层在面孔处理任务期间对面孔处理任务对面孔处理任务中的枕叶皮层施加了非常早期的影响，并且右额颞皮质区域的兴奋性在明确的面部表情处理过程中明显调节。
