MOTOR SYSTEM MODULATION FOR MOVEMENT DIRECTION AND ROTATION ANGLE DURING MOTOR IMAGERY

作者：Pizzolato F; Fiorio M; Cesari P^*

来源：Neuroscience, 2012, 218: 154-160.

DOI：10.1016/j.neuroscience.2012.05.031

• transcranial magnetic stimulation
• movement direction
• rotation angle
• motor cortex
• imagination

Transcranial magnetic stimulation (TMS) studies have shown that the motor system is facilitated when we imagine performing motor actions. However, it is not clear whether the individual%26apos;s motor system modulates bilaterally and selectively for task parameters, such as movement direction and amplitude. To investigate this issue, we applied single-pulse TMS over the left and right primary motor cortex (M1) of healthy subjects, who had to imagine grasping and rotating a clock hour hand, having a starting position at noon, towards four different times: 2, 5, 7 and 10 o%26apos;clock. Rotations could be in clockwise (2 and 5 o%26apos;clock) or counter-clockwise (7 and 10 o%26apos;clock) directions and could require small (2 and 10 o%26apos;clock) or large (5 and 7 o%26apos;clock) rotation angle. TMS motor-evoked potentials were recorded for three muscles, and movements were imagined with the right and left hands. Results showed that during motor imagery a mirroring pattern was present between the right and the left motor cortices, showing selective activation of the hand-intrinsic muscles spatially close to the direction of the imagined movement. Overall a higher activation for large and a lower activation for small rotation angle were found, but no selective muscle activity was present within the hand-intrinsic muscles for this parameter. Following these results we propose that during action imagination an internally coded covariance between movement parameters is present with a muscle-specific activation for movement direction.

• 出版日期2012-8-30