Research Institute, Hospital for Sick Children, University of Toronto, Canada.
Brain Res. 2012 Feb 23;1439:44-53. doi: 10.1016/j.brainres.2011.11.042. Epub 2011 Dec 1.
Another person's eye gaze often triggers our attention such that we follow their direction of gaze. We investigated how the neural mechanisms for processing eye-gaze and spatial attention interact using magnetoencephalography (MEG) in young adults. In a cueing paradigm, a face was presented centrally with left or right averted eye-gaze serving as the directional cue in the eye-gaze condition. In the peripheral cue condition, the face with a straight gaze was presented with a cue stimulus appearing on the left or right of the face. Cue validity was 50%. MEG was recorded during the two conditions and event-related beamforming was used to determine the timing and location of the brain activity related to the two types of cueing. The MEG data indicated that generally the network of activation in response to our two cue types was similar. In contrast, MEG responses to the targets demonstrated one main peak at 286-306 ms for the eye-gaze cue condition while two peaks were found at 238-258 ms and 286-306 ms for the peripheral cue condition. Activation was also consistently larger for the invalid than valid trials. Source images for the invalid minus valid contrasts for the 238-258 ms window showed significant activation only in the peripheral cueing condition, in the left temporoparietal junction and left inferior frontal gyrus. In the 286-306 ms window, both conditions showed left medial frontal activations. Thus, peripheral cues showed more rapid neural processing than the eye-gaze cues, with the second component being common to both, reflecting in part common processing. We suggest that attentional processing was maximal in the left hemisphere, as the right hemisphere was likely engaged in processing the face information.
他人的目光注视通常会引起我们的注意，使我们跟随他们的注视方向。我们使用脑磁图 (MEG) 研究了处理目光注视和空间注意的神经机制如何相互作用。在提示范式中，一张脸呈现在中央，左或右斜视作为目光注视条件下的方向提示。在周边提示条件下，直目光的脸伴随着出现在脸的左或右的提示刺激。提示有效性为 50%。在两种条件下记录 MEG，并使用事件相关波束形成来确定与两种提示类型相关的大脑活动的时间和位置。MEG 数据表明，通常，对我们两种提示类型的反应的激活网络是相似的。相比之下，对于目光注视提示条件，目标的 MEG 反应在 286-306 ms 时出现一个主要峰值，而对于周边提示条件，在 238-258 ms 和 286-306 ms 时发现两个峰值。对于无效试验，激活也始终大于有效试验。对于 238-258 ms 窗口的无效减去有效对比的源图像显示，仅在外周提示条件下，在左颞顶联合区和左额下回出现显著激活。在 286-306 ms 窗口，两种条件均显示左内侧额激活。因此，周边提示比目光注视提示显示出更快的神经处理，第二个成分对两者都有影响，部分反映了共同的处理。我们认为，注意力处理在左半球达到最大值，因为右半球可能参与了对面部信息的处理。
