Berner Julia, Schönfeldt-Lecuona Carlos, Nowak Dennis A
Department of Psychiatry III, University of Ulm, Germany.
Neuropsychologia. 2007 Apr 9;45(8):1931-8. doi: 10.1016/j.neuropsychologia.2006.11.011. Epub 2007 Jan 19.
When an object is repetitively lifted, the scaling of grip force is influenced by the mechanical properties of the preceding lift, suggesting the formation of a sensorimotor memory. Similar effects on force scaling are observed when the subsequent lift is performed with the hand opposite to the preceding lift. We used neuronavigated rTMS over the hand area of the dominant primary motor cortex to investigate its role in setting up sensorimotor memory. After ten lifts of a novel object with the dominant hand either rTMS or a period of motor rest commenced, until another set of lifts was performed with either the same or opposite hand. Compared to motor rest, rTMS caused underestimation of the object's weight when given 10 or 30s after the previous set of lifts, but overestimation of the object's weight when applied 60 or 120 s after the previous set of lifts, regardless of the hand performing the lift. Our interpretation of the data is that (a) the primary motor cortex is essential for setting up sensorimotor memory related to the mechanical object properties during manipulation and (b) rTMS can induce bidirectional changes of grip efficiency within the dynamics of sensorimotor integration.
当反复提起一个物体时，握力的缩放受到前一次提起动作的机械特性的影响，这表明形成了一种感觉运动记忆。当用与前一次提起动作相反的手进行后续提起动作时，也会观察到对力的缩放有类似的影响。我们使用神经导航重复经颅磁刺激（rTMS）作用于优势侧初级运动皮层的手部区域，以研究其在建立感觉运动记忆中的作用。先用优势手对一个新物体进行十次提起动作后，要么开始进行rTMS，要么进行一段时间的运动休息，直到用同一只手或相反的手进行另一组提起动作。与运动休息相比，在前一组提起动作后10秒或30秒施加rTMS时，会导致对物体重量的低估，但在前一组提起动作后60秒或120秒施加rTMS时，会导致对物体重量的高估，无论进行提起动作的是哪只手。我们对这些数据的解释是：（a）初级运动皮层对于在操作过程中建立与物体机械特性相关的感觉运动记忆至关重要；（b）rTMS可以在感觉运动整合的动态过程中诱导握力效率的双向变化。
