FMRI Studies Of Cognitive Judgment Of Hand Movements Simulation

Embodied cognition emphasizes the formative role of the organism’s body structure and sensor motor systems in the development of mind and cognitive processes, Previous studies proved that motor simulation played a functional role in identifying tools, which described that only seeing objects that were typically manipulated in certain ways automatically triggered motor simulation for using them. Motor imagery is widely used to study cognitive aspects of the neural control of action. Different hands postures can influence the motor simulation, but whether the neuromechanism of motor simulation was affected, which was to be further researched.To explore the effects and neuromechanism of motor simulation on cognitive judgment, we used functional magnetic resonance imaging (fMRI) to scan subjects’brain activation while they made laterality judgment on the familiar graspable tools under three experimental conditions, which included non-grasping ball, grasping ball with left hand and grasp ball with right hand. Eighteen participants (10females and8males, age range from21to26, M=23.7±2.6) took part in the experiment. The participants were all right-hand with normal or corrected-to-normal vision and had no neurological or psychological disorders. During the experiment, participants were presented with pictures of familiar graspable tools and ordered to make judgment on the laterality of those tools’ handle under interference or no interference conditions.Behavioral results revealed that there was a significant interaction between hands postures status and the orientation of the tools’handle. In the nature condition participants were faster in judging the orientation when grasping nothing than grasping the ball in their hands, and there was no significant effect between the left and right orientations.Besides, participants were faster when the handle of the tool was away from the grasping hand, in other words, subjects were faster in judging the right orientation of tools’handle when they were grasping the ball with their left hands than in judging the left one, on the other hand, they were faster in judging the left orientation.Imaging results suggested that there were significant activations in the inferior parietal lobule, middle frontal gyrus, inferior frontal gyrus and supplementary motor area under the nature condition. What’s more, the inferior parietal lobule, middle frontal gyrus, supplementary motor area, precuneus, cingulate gyrus and the hippocampus were significantly activated on the interaction between hands postures status and the orientation of the tools’handle.All the above results showed that the neuromechanism of motor simulation focused on the mirror neuron systems, and the MNS played a key role in the process of tools’ orientation judgment. Hand posture status could not only affect the process of cognition, but also interfere with the process of motor simulation.