Rinsma Thijs, van der Kamp John, Dicks Matt, Cañal-Bruland Rouwen
Research Institute MOVE Amsterdam, Faculty of Behavioural and Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands.
Institute of Human Performance, University of Hong Kong, Hong Kong SAR, China.
Exp Brain Res. 2017 Jun;235(6):1823-1833. doi: 10.1007/s00221-016-4868-1. Epub 2017 Mar 15.
In a recent amendment to the two-visual-system model, it has been proposed that actions must result in tactile contact with the goal object for the dorsal system to become engaged (Whitwell et al., Neuropsychologia 55:41-50, 2014). The present study tested this addition by assessing the use of allocentric information in normal and pantomime actions. To this end, magicians, and participants who were inexperienced in performing pantomime actions made normal and pantomime grasps toward objects embedded in the Müller-Lyer illusion. During pantomime grasping, a grasp was made next to an object that was in full view (i.e., a displaced pantomime grasping task). The results showed that pantomime grasps took longer, were slower, and had smaller hand apertures than normal grasping. Most importantly, hand apertures were affected by the illusion during pantomime grasping but not in normal grasping, indicating that displaced pantomime grasping is based on allocentric information. This was true for participants without experience in performing pantomime grasps as well as for magicians with experience in pantomiming. The finding that the illusory bias is limited to pantomime grasping and persists with experience supports the conjecture that the normal engagement of the dorsal system's contribution requires tactile contact with a goal object. If no tactile contact is made, then movement control shifts toward the ventral system.
在双视觉系统模型的近期一项修正中，有人提出，动作必须导致与目标物体的触觉接触，背侧系统才会被激活（惠特韦尔等人，《神经心理学》55:41 - 50，2014年）。本研究通过评估正常动作和模仿动作中对空间信息的使用来检验这一补充内容。为此，魔术师以及没有模仿动作经验的参与者对嵌入缪勒 - 莱尔错觉中的物体进行正常抓握和模仿抓握。在模仿抓握过程中，在完全可见的物体旁边进行抓握动作（即移位模仿抓握任务）。结果表明，模仿抓握比正常抓握花费时间更长、速度更慢且手部张角更小。最重要的是，在模仿抓握过程中手部张角受错觉影响，而在正常抓握中不受影响，这表明移位模仿抓握是基于空间信息的。对于没有模仿抓握经验的参与者以及有模仿经验的魔术师来说都是如此。虚幻偏差仅限于模仿抓握且随着经验持续存在这一发现支持了这样的推测，即背侧系统发挥作用的正常激活需要与目标物体的触觉接触。如果没有进行触觉接触，那么运动控制就会转向腹侧系统。
