Lafargue Gilles, Paillard Jacques, Lamarre Yves, Sirigu Angela
Institut des Sciences Cognitives, CNRS, 67 boulevard Pinel, 69675 Bron, Lyon, France.
Eur J Neurosci. 2003 Jun;17(12):2741-9. doi: 10.1046/j.1460-9568.2003.02700.x.
We assessed the ability of healthy subjects (n = 7) and a patient deprived of proprioception (GL) to produce and assess different levels of isometric forces. They first produced a target force with one hand (the reference control hand) and then, after a delay of 3 s, they attempted to match it with the other hand (the experimental matching hand). Despite abnormal variations in motor outputs, we found that GL could, as could the control subjects, maintain a constant relationship between the force exerted by the control hand and the force exerted by the experimental hand. As GL was deprived of proprioceptive cues, these results suggest that she indirectly perceived muscular force through central effort. Interestingly, when carrying out the task the patient reported neither feelings of fatigue nor awareness of how hard she tried to perform the matches. Hence, under certain circumstances (such as in our motor task), it seems possible to assess and scale muscular force on the basis of endogenous signals only. However, internally generated signals related to the size of the motor command may need to interact with afferent input to gain full access to consciousness.
我们评估了健康受试者（n = 7）和一名本体感觉缺失患者（GL）产生和评估不同水平等长力的能力。他们首先用一只手（参考对照手）产生一个目标力，然后在延迟3秒后，尝试用另一只手（实验匹配手）与之匹配。尽管运动输出存在异常变化，但我们发现，与对照受试者一样，GL能够保持对照手施加的力与实验手施加的力之间的恒定关系。由于GL缺乏本体感觉线索，这些结果表明她通过中枢努力间接感知肌肉力量。有趣的是，在执行任务时，患者既没有感到疲劳，也没有意识到自己为完成匹配付出了多大努力。因此，在某些情况下（如我们的运动任务），似乎仅基于内源性信号就可以评估和标定肌肉力量。然而，与运动指令大小相关的内部生成信号可能需要与传入输入相互作用，才能完全进入意识。
