Department of Physiology and Biophysics, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
PLoS One. 2011;6(11):e26859. doi: 10.1371/journal.pone.0026859. Epub 2011 Nov 2.
The neural mechanisms mediating the activation of the motor system during action observation, also known as motor resonance, are of major interest to the field of motor control. It has been proposed that motor resonance develops in infants through Hebbian plasticity of pathways connecting sensory and motor regions that fire simultaneously during imitation or self movement observation. A fundamental problem when testing this theory in adults is that most experimental paradigms involve actions that have been overpracticed throughout life. Here, we directly tested the sensorimotor theory of motor resonance by creating new visuomotor representations using abstract stimuli (motor symbols) and identifying the neural networks recruited through fMRI. We predicted that the network recruited during action observation and execution would overlap with that recruited during observation of new motor symbols. Our results indicate that a network consisting of premotor and posterior parietal cortex, the supplementary motor area, the inferior frontal gyrus and cerebellum was activated both by new motor symbols and by direct observation of the corresponding action. This tight spatial overlap underscores the importance of sensorimotor learning for motor resonance and further indicates that the physical characteristics of the perceived stimulus are irrelevant to the evoked response in the observer.
介导动作观察时运动系统激活的神经机制，也称为运动共振，是运动控制领域的主要关注点。有人提出，通过在模仿或自我运动观察时同时发射的感觉和运动区域之间的连接通路的赫布可塑性，运动共振在婴儿中发展。在成年人中测试该理论的一个基本问题是，大多数实验范式都涉及一生中反复练习的动作。在这里，我们通过使用抽象刺激（运动符号）创建新的运动表象，并通过 fMRI 识别所招募的神经网络，直接测试运动共振的感觉运动理论。我们预测，在动作观察和执行期间招募的网络将与新的运动符号观察期间招募的网络重叠。我们的结果表明，由运动前皮质和后顶叶皮质、辅助运动区、下额叶回和小脑组成的网络既可以通过新的运动符号激活，也可以通过直接观察相应的动作激活。这种紧密的空间重叠强调了感觉运动学习对运动共振的重要性，并进一步表明，观察者感知刺激的物理特征与诱发反应无关。
