School of Psychology, the University of Nottingham, Nottingham NG7 2RD, UK.
J Neurosci. 2011 Aug 17;31(33):12001-10. doi: 10.1523/JNEUROSCI.0845-11.2011.
Spontaneous mimicry of other people's actions serves an important social function, enhancing affiliation and social interaction. This mimicry can be subtly modulated by different social contexts. We recently found behavioral evidence that direct eye gaze rapidly and specifically enhances mimicry of intransitive hand movements (Wang et al., 2011). Based on past findings linking medial prefrontal cortex (mPFC) to both eye contact and the control of mimicry, we hypothesized that mPFC might be the neural origin of this behavioral effect. The present study aimed to test this hypothesis. During functional magnetic resonance imaging (fMRI) scanning, 20 human participants performed a simple mimicry or no-mimicry task, as previously described (Wang et al., 2011), with direct gaze present on half of the trials. As predicted, fMRI results showed that performing the task activated mirror systems, while direct gaze and inhibition of the natural tendency to mimic both engaged mPFC. Critically, we found an interaction between mimicry and eye contact in mPFC, superior temporal sulcus (STS) and inferior frontal gyrus. We then used dynamic causal modeling to contrast 12 possible models of information processing in this network. Results supported a model in which eye contact controls mimicry by modulating the connection strength from mPFC to STS. This suggests that mPFC is the originator of the gaze-mimicry interaction and that it modulates sensory input to the mirror system. Thus, our results demonstrate how different components of the social brain work together to on-line control mimicry according to the social context.
他人动作的自发性模仿具有重要的社会功能，可以增强亲和感和社会互动。这种模仿可以通过不同的社会环境微妙地调节。我们最近发现行为证据表明，直接眼神注视可以快速而特定地增强对非传递性手部动作的模仿（Wang 等人，2011）。基于过去将内侧前额叶皮层（mPFC）与眼神接触和模仿控制联系起来的发现，我们假设 mPFC 可能是这种行为效应的神经起源。本研究旨在检验这一假设。在功能磁共振成像（fMRI）扫描期间，20 名人类参与者按照之前的描述（Wang 等人，2011）进行了简单的模仿或不模仿任务，其中一半的试验中存在直接注视。正如预测的那样，fMRI 结果表明，执行任务激活了镜像系统，而直接注视和抑制自然模仿倾向都参与了 mPFC。至关重要的是，我们在 mPFC、颞上沟（STS）和下额前回中发现了模仿和眼神接触之间的相互作用。然后，我们使用动态因果建模对比了该网络中 12 种可能的信息处理模型。结果支持了这样一种模型，即眼神接触通过调节从 mPFC 到 STS 的连接强度来控制模仿。这表明 mPFC 是注视-模仿相互作用的起源，它调节了对镜像系统的感觉输入。因此，我们的结果表明，社会大脑的不同组成部分如何根据社会环境协同工作，在线控制模仿。
