School of Psychology, University of Newcastle, Australia.
QIMR Berghofer Medical Research Institute, Australia.
Neuropsychologia. 2021 Oct 15;161:108021. doi: 10.1016/j.neuropsychologia.2021.108021. Epub 2021 Sep 10.
Perceiving, anticipating and responding to the actions of another person are fundamentally entwined processes such that seeing another's movement can prompt automatic imitation, as in social mimicry and contagious yawning. Yet the direct-matching of others' movements is not always appropriate, so this tendency must be controlled. This necessitates the hierarchical integration of the systems for action mirroring with domain-general control networks. Here we use functional magnetic resonance imaging (fMRI) and computational modelling to examine the top-down and context-dependent modulation of mirror representations and their influence on motor planning. Participants performed actions that either intentionally or incidentally imitated, or counter-imitated, an observed action. Analyses of these fMRI data revealed a region in the mid-occipital gyrus (MOG) where activity differed between imitation versus counter-imitation in a manner that depended on whether this was intentional or incidental. To identify broader cortical network mechanisms underlying this interaction between intention and imitativeness, we used dynamic causal modelling to pose specific hypotheses which embody assumptions about inter-areal interactions and contextual modulations. These models each incorporated four regions - medial temporal V5 (early motion perception), MOG (action-observation), supplementary motor area (action planning), and anterior insula (executive control) - but differ in their interactions and hierarchical structure. The best model of our data afforded a crucial role for the anterior insula, gating the interaction of supplementary motor area and MOG activity. This provides a novel brain network-based account of task-dependent control over the integration of motor planning and mirror systems, with mirror responses suppressed for intentional counter-imitation.
感知、预测和回应他人的行为是基本交织在一起的过程，以至于看到他人的动作会引发自动模仿，例如社交模仿和传染性哈欠。然而，直接匹配他人的动作并不总是合适的，因此这种趋势必须得到控制。这就需要动作镜像系统与通用控制网络的分层整合。在这里，我们使用功能磁共振成像（fMRI）和计算建模来研究镜像表示的自上而下和上下文相关的调制及其对运动规划的影响。参与者执行的动作要么是故意模仿、意外模仿，要么是反模仿观察到的动作。对这些 fMRI 数据的分析揭示了中枕回（MOG）中的一个区域，其活动在模仿与反模仿之间存在差异，这种差异取决于这种模仿是故意的还是偶然的。为了确定意图和模仿性之间这种相互作用的更广泛的皮质网络机制，我们使用动态因果建模来提出具体的假设，这些假设体现了对区域间相互作用和上下文调制的假设。这些模型都包含四个区域——内侧颞叶 V5（早期运动感知）、MOG（动作观察）、辅助运动区（动作规划）和前脑岛（执行控制）——但它们的相互作用和层次结构不同。我们数据的最佳模型为前脑岛提供了一个关键作用，即门控辅助运动区和 MOG 活动的相互作用。这为基于大脑网络的任务相关控制提供了一种新的解释，即抑制了对故意反模仿的镜像反应。
