Neurocognition and Action Research Group, Department of Sport Science, Faculty of Psychology and Sport Science, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany.
Neurosci Lett. 2013 Feb 8;534:139-44. doi: 10.1016/j.neulet.2012.11.034. Epub 2012 Nov 29.
The function of thumb posture in mental rotation has not yet been studied intensely, despite its special role in manual action. To investigate if thumb posture modifies relative visual and proprioceptive contributions, we conducted two experiments comprising hand laterality judgement tasks with identical stimuli (left and right hands in palmar and dorsal views presented at four orientations). In half of the stimuli, all digits were extended, whereas in the other half the thumb was flexed into the palm of the hand. In the second experiment, participants' thumbs were taped in the same flexed posture that was displayed in half of the stimuli one hour previous to and throughout the experiment. Results of both experiments revealed effects of orientation, side and view on reaction time, but an effect of stimulus thumb posture occurred only in the second experiment in which participants' thumbs were fixed. In palmar view, stimuli rotated by 90° with fingers pointing towards the participant's midline had shorter reaction times than stimuli rotated (evidentially less comfortably) in the opposite direction. This finding suggests that participants applied motor imagery strategies for palmar but not for dorsal views of the hand, indicating a difference in visual and sensorimotor familiarity.
尽管拇指姿势在手动操作中具有特殊作用，但它在心理旋转中的功能尚未得到深入研究。为了研究拇指姿势是否会改变相对视觉和本体感觉的贡献，我们进行了两项实验，这些实验包括使用相同刺激的手偏向判断任务（在四个方向上呈现手掌和手背视图的左手和右手）。在一半的刺激中，所有手指都伸展，而在另一半刺激中，拇指弯曲到手掌中。在第二项实验中，参与者的拇指在实验前一小时和整个实验过程中都用胶带固定在与一半刺激中显示的相同弯曲姿势。两个实验的结果都显示了方向、侧和视图对反应时间的影响，但只有在参与者的拇指被固定的第二项实验中才出现了刺激拇指姿势的影响。在手掌视图中，与手指指向参与者中线的 90°旋转的刺激相比，以相反方向旋转（明显不那么舒适）的刺激具有更短的反应时间。这一发现表明，参与者对手掌视图而不是手背视图应用了运动意象策略，表明视觉和运动感觉的熟悉度存在差异。
