Laboratory of Brain and Cognition, National Institute for Mental Health, Bethesda, Maryland 20892
J Neurosci. 2014 Jul 2;34(27):9173-7. doi: 10.1523/JNEUROSCI.5038-13.2014.
Neuroimaging studies have identified a face-selective region in the right posterior superior temporal sulcus (rpSTS) that responds more strongly during facial expression recognition tasks than during facial identity recognition tasks, but precisely when the rpSTS begins to causally contribute to expression recognition is unclear. The present study addressed this issue using transcranial magnetic stimulation (TMS). In Experiment 1, repetitive TMS delivered over the rpSTS of human participants, at a frequency of 10 Hz for 500 ms, selectively impaired a facial expression task but had no effect on a matched facial identity task. In Experiment 2, participants performed the expression task only while double-pulse TMS (dTMS) was delivered over the rpSTS or over the right occipital face area (rOFA), a face-selective region in lateral occipital cortex, at different latencies up to 210 ms after stimulus onset. Task performance was selectively impaired when dTMS was delivered over the rpSTS at 60-100 ms and 100-140 ms. dTMS delivered over the rOFA impaired task performance at 60-100 ms only. These results demonstrate that the rpSTS causally contributes to expression recognition and that it does so over a longer time-scale than the rOFA. This difference in the length of the TMS induced impairment between the rpSTS and the rOFA suggests that the neural computations that contribute to facial expression recognition in each region are functionally distinct.
神经影像学研究已经确定了右侧后上颞叶（rpSTS）中的一个面孔选择性区域，该区域在进行面部表情识别任务时比进行面部身份识别任务时反应更强烈，但确切地说，rpSTS 何时开始对表情识别产生因果影响尚不清楚。本研究使用经颅磁刺激（TMS）解决了这个问题。在实验 1 中，对人类参与者的 rpSTS 进行重复 TMS 刺激，频率为 10 Hz，持续 500 ms，选择性地损害了面部表情任务，但对面部身份识别任务没有影响。在实验 2 中，当双脉冲 TMS（dTMS）在刺激开始后 60-100ms 和 100-140ms 时分别施加到 rpSTS 或右侧枕面区（rOFA）（外侧枕叶皮层中的一个面孔选择性区域）时，参与者仅执行表情任务。当 dTMS 施加到 rpSTS 时，任务表现选择性受损在 60-100ms 和 100-140ms 时。当 dTMS 施加到 rOFA 时，仅在 60-100ms 时损害任务表现。这些结果表明，rpSTS 对表情识别有因果贡献，而且其作用时间尺度比 rOFA 长。rpSTS 和 rOFA 之间 TMS 诱导的损伤长度的这种差异表明，每个区域中有助于面部表情识别的神经计算在功能上是不同的。
