Neurocognition and Action Research Group and Center of Excellence Cognitive Interaction Technology (EXC 277), Bielefeld University, PB 100131, 33501 Bielefeld, Germany.
Exp Brain Res. 2012 Aug;221(1):93-105. doi: 10.1007/s00221-012-3151-3. Epub 2012 Jul 6.
Mental rotation of human hands has been found to differ essentially from mental rotation of objects in such a way that reaction times and error rates of handedness judgements are influenced by the comfort and familiarity of the presented hand postures. To investigate the role of the similarity of the presented hands to the participant's own hand, we used different primates' hands as stimuli in a mental rotation task. Five out of 24 primate hands were chosen for their ratings in human-likeness and saliency of the thumb according to a questionnaire study and presented in two mental rotation experiments; in the second experiment, they were modified in such a way that all hands appeared thumbless. Results of both experiments revealed effects of species and orientation on reaction times, and an interaction between species and hand side occurred in the second experiment. In the first experiment, the thumbless Colobus hand differed from all other hands, showing the highest reaction times and error rates and failing to show the expected medial-over-lateral advantage. In the second experiment, the eccentricity of the Colobus hand was decreased and the facilitating effect of human-likeness was slightly increased. We conclude that motor strategies were applied that relied less on the asymmetry of the stimuli but rather on their similarity to the human hand. We argue that motor simulation might facilitate the processing of incomplete stimuli by mentally completing them, especially if all stimuli can be processed in a consistent manner.
人手的心理旋转与物体的心理旋转在本质上存在差异，因为手的姿势的舒适度和熟悉度会影响到手性判断的反应时间和错误率。为了研究呈现的手与参与者自身手的相似性的作用，我们在心理旋转任务中使用了不同灵长类动物的手作为刺激。根据问卷调查研究，选择了五只灵长类动物的手作为其人类似度和拇指显著性的评分，它们在两个心理旋转实验中被呈现；在第二个实验中，它们被修改为所有手都没有拇指。两个实验的结果都揭示了物种和方向对反应时间的影响，并且在第二个实验中，物种和手侧之间存在相互作用。在第一个实验中，无拇指的疣猴手与所有其他手不同，表现出最高的反应时间和错误率，并且未能表现出预期的中线优势。在第二个实验中，疣猴手的偏心度降低，人类似度的促进作用略有增加。我们得出结论，应用了运动策略，这些策略较少依赖于刺激的不对称性，而是依赖于它们与人类手的相似性。我们认为，运动模拟可能通过在心理上完成它们来促进对不完整刺激的处理，尤其是如果所有刺激都可以以一致的方式进行处理。
