Manser-Smith Kelda, Tamè Luigi, Longo Matthew R
Department of Psychological Sciences.
J Exp Psychol Hum Percept Perform. 2018 Nov;44(11):1727-1738. doi: 10.1037/xhp0000566. Epub 2018 Aug 9.
Recent research has shown systematic patterns of confusions between digits of the hands and feet. The present study addressed whether such confusions arise from early somatosensory maps or higher level body representations. As the glabrous and hairy skin of the hands and feet have distinct representations in somatosensory cortex, an effect arising from early somatotopic maps may show distinct patterns on each skin surface. In contrast, if the effect arises from higher level body representations which represent the digits as volumetric units, similar patterns should be apparent regardless of which side of the digit is touched. We obtained confusion matrices showing the pattern of mislocalization on the glabrous and hairy skin surfaces of the toes (Experiment 1) and fingers (Experiment 2). Our results replicated the characteristic pattern of mislocalizations found on the glabrous skin reported in previous studies. Critically, these effects were highly similar on the hairy skin surface of both the toes and fingers. Despite the pattern of mislocalizations being highly stereotyped across participants, there were consistent individual differences in the pattern of confusions across the two skin surfaces. These results suggest that mislocalizations occur at the level of individual digits, consistent with their resulting from higher level body representations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
近期研究显示，在手和脚的数字之间存在系统性的混淆模式。本研究探讨了这种混淆是否源于早期的躯体感觉图谱或更高级别的身体表征。由于手和脚的无毛皮肤和多毛皮肤在躯体感觉皮层中有不同的表征，早期躯体定位图谱产生的效应可能在每个皮肤表面呈现出不同的模式。相比之下，如果效应源于将手指作为体积单位来表征的更高级别身体表征，那么无论触碰手指的哪一侧，都应该会出现相似的模式。我们获得了混淆矩阵，展示了在脚趾（实验1）和手指（实验2）的无毛皮肤和多毛皮肤表面上的错误定位模式。我们的结果复制了先前研究中在无毛皮肤上发现的错误定位特征模式。关键的是，这些效应在脚趾和手指的多毛皮肤表面上非常相似。尽管参与者之间的错误定位模式高度刻板，但在两个皮肤表面的混淆模式上存在一致的个体差异。这些结果表明，错误定位发生在单个手指的层面，这与它们源于更高级别身体表征的结果一致。（PsycINFO数据库记录（c）2018美国心理学会，保留所有权利）
