熟练的运动性能在很大程度上取决于快速的校正响应,这些响应可在扰动时保持运动的目标。尽管众所周知,在到达对象时产生的纠正性响应的增益可以适应不同的环境,很少有人知道的适应性的纠正反应支持操纵对象后,他们被抓住。在这里,我们研究了当被抬起的物体比预期的重并且无法在预测时抬起时引起的校正响应的适应性。此响应涉及触发的垂直负载力的单调增加,在90毫秒内,由于缺乏预期的感觉反馈信号,并在发生实际提离时终止。严重的,因为在物体无法抬离的瞬间无法直接感知物体的实际重量,校正响应的任何适应都必须基于先前提升的记忆。我们证明当人类,包括男人和女人,反复举起一个物体,偶尔试捕,从基线重量增加到固定的较重重量,他们缩放响应的增益(即,力增加的速率)在2-3个捕捞试验中增加到较重的重量。我们还表明,响应量表的增益,在第一次抓捕审判中,与对象的基线权重。因此,提升反应的增益可以通过短期和长期经验来适应。最后,我们证明,这种适应保留了跨上下文的反应的有效性。重要性声明在这里,我们首次研究了当物体比预期重并且无法在预测时抬起时引起的校正性抬起响应的适应性。回应的一个显著特征,这是由缺乏预期的感官反馈而产生的感官预测误差驱动的,错误的大小是未知的。也就是说,电机系统只收到一个分类错误,表明物体比预期重,而不是它的实际重量。尽管在引起响应的那一刻不知道误差大小,我们表明,响应可以根据近期和长期记忆来扩展到误差大小的预测。
Skilled motor performance depends critically on rapid corrective responses that act to preserve the goal of the movement in the face of perturbations. Although it is well established that the gain of corrective responses elicited while reaching toward objects adapts to different contexts, little is known about the adaptability of corrective responses supporting the manipulation of objects after they are grasped. Here, we investigated the adaptability of the corrective response elicited when an object being lifted is heavier than expected and fails to lift off when predicted. This response involves a monotonic increase in vertical load force triggered, within ∼90 ms, by the absence of expected sensory feedback signaling lift off and terminated when actual lift off occurs. Critically, because the actual weight of the object cannot be directly sensed at the moment the object fails to lift off, any adaptation of the corrective response would have to be based on memory from previous lifts. We show that when humans, including men and women, repeatedly lift an object that on occasional catch trials increases from a baseline weight to a fixed heavier weight, they scale the gain of the response (i.e., the rate of force increase) to the heavier weight within two to three catch trials. We also show that the gain of the response scales, on the first catch trial, with the baseline weight of the object. Thus, the gain of the lifting response can be adapted by both short- and long-term experience. Finally, we demonstrate that this adaptation preserves the efficacy of the response across contexts.SIGNIFICANCE STATEMENT Here, we present the first investigation of the adaptability of the corrective lifting response elicited when an object is heavier than expected and fails to lift off when predicted. A striking feature of the response, which is driven by a sensory prediction error arising from the absence of expected sensory feedback, is that the magnitude of the error is unknown. That is, the motor system only receives a categorical error indicating that the object is heavier than expected but not its actual weight. Although the error magnitude is not known at the moment the response is elicited, we show that the response can be scaled to predictions of error magnitude based on both recent and long-term memories.