Bertonati Giorgia, Gori Monica, Smeets Jeroen B J, Brenner Eli
Unit for Visually Impaired People (UVIP), Istituto Italiano di Tecnologia, Genoa, Italy.
DIBRIS Department, Università degli studi di Genova, Genoa, Italy.
Exp Brain Res. 2025 Jun 9;243(7):171. doi: 10.1007/s00221-025-07108-6.
Goal-directed movements are constantly guided by the latest information about the target's position. Nevertheless, movements seldom end perfectly on target, so subsequent movements are adjusted to avoid repeating errors. One could intercept moving targets at different positions at different times, so one could adjust both the position and the timing of the endpoint of both the current and the next movement. It could be advantageous to rely more on adjusting the timing for faster targets, because for faster targets a change in timing corresponds with a larger change in position. We therefore examined how participants responded to 'errors' that were introduced by having slow and fast targets jump slightly backwards or forwards along their path. If there was enough time to adjust the ongoing movement after the jump, timing was indeed responsible for a larger fraction of the adjustment for fast targets. But the actual change in timing did not depend on the target's speed. The same change in timing compensated for a larger part of the error for fast targets, so the position could change less. If there was not enough time to adjust the ongoing movement, neither the timing nor the position on the next trial changed differently for the different target speeds. Consequently, a larger fraction of the error was compensated for if the target moved faster. Thus, how people adjust their timing does not depend on the target's speed, but the same change to the timing has more impact if the target is moving faster.
目标导向运动不断地由关于目标位置的最新信息引导。然而，运动很少能完美地在目标处结束，所以后续运动会进行调整以避免重复错误。人们可以在不同时间在不同位置拦截移动目标，所以可以调整当前和下一次运动终点的位置和时间。对于速度较快的目标，更多地依赖于调整时间可能是有利的，因为对于速度较快的目标，时间的变化对应着位置的更大变化。因此，我们研究了参与者如何应对通过让慢速和快速目标沿其路径稍微向后或向前跳跃而引入的“误差”。如果在跳跃后有足够的时间调整正在进行的运动，那么对于快速目标，时间确实在调整中占更大比例。但时间的实际变化并不取决于目标的速度。相同的时间变化能补偿快速目标更大比例的误差，所以位置变化可以更小。如果没有足够的时间调整正在进行的运动，那么对于不同的目标速度，下一次试验中的时间和位置变化都没有差异。因此，如果目标移动得更快，误差的更大比例会得到补偿。所以，人们如何调整时间并不取决于目标的速度，但如果目标移动得更快，相同的时间变化会产生更大的影响。
