De Stefani Elisa, Innocenti Alessandro, De Marco Doriana, Busiello Marianna, Ferri Francesca, Costantini Marcello, Gentilucci Maurizio
Department of Neuroscience, University of Parma, Via Volturno 39, 43100, Parma, Italy.
Exp Brain Res. 2014 Jul;232(7):2431-8. doi: 10.1007/s00221-014-3943-8. Epub 2014 Apr 20.
The present experiment aimed at verifying whether the spatial alignment effect modifies kinematic parameters of pantomimed reaching-grasping of cups located at reachable and not reachable distance. The cup's handle could be oriented either to the right or to the left, thus inducing a grasp movement that could be either congruent or incongruent with the pantomime. The incongruence/congruence induced an increase/decrease in maximal finger aperture, which was observed when the cup was located near but not far from the body. This effect probably depended on influence of the size of the cup body on pantomime control when, in the incongruent condition, cup body was closer to the grasp hand as compared to the handle. Cup distance (near and far) influenced the pantomime even if it was actually executed in the same peripersonal space. Specifically, arm and hand temporal parameters were affected by actual cup distance as well as movement amplitudes. The results indicate that, when executing a reach-to-grasp pantomime, affordance related to the use of the object was instantiated (and in particular the spatial alignment effect became effective), but only when the object could be actually reached. Cup distance (extrinsic object property) influenced affordance, independently of the possibility to actually reach the target.
本实验旨在验证空间对齐效应是否会改变对位于可及和不可及距离处杯子进行抓握动作模仿的运动学参数。杯子的把手可以朝右或朝左，从而引发一种抓握动作，该动作可能与模仿动作一致或不一致。不一致/一致会导致最大手指开度增加/减少，这种情况在杯子位于靠近身体但不远处时会观察到。这种效应可能取决于杯子主体大小对模仿动作控制的影响，在不一致的情况下，与把手相比，杯子主体更靠近抓握的手。杯子距离（近和远）即使是在同一近体空间内实际执行模仿动作时也会对其产生影响。具体而言，手臂和手部的时间参数以及运动幅度会受到实际杯子距离的影响。结果表明，在执行伸手抓握模仿动作时，与物体使用相关的可供性被实例化（特别是空间对齐效应变得有效），但前提是物体实际上能够够到。杯子距离（物体的外在属性）会影响可供性，而与实际够到目标的可能性无关。
