Kwon Jay C, Lee Byung H, Ji Jung Min, Jeong Yong, Kim Bong Jik, Heilman Kenneth M, Na Duk L
Department of Neurology, Changwon Fatima Hospital, Changwon, Korea.
J Int Neuropsychol Soc. 2004 Oct;10(6):913-9. doi: 10.1017/s1355617704106152.
We investigated whether the perception or production of a given line length in normal subjects varies according to where in peripersonal space the line is perceived or produced. We also investigated the influence of the direction of movement used to make the line. In Experiment 1, blindfolded normal subjects were asked to estimate distances while the examiner moved the subject's hand in proximal (medial) or distal (lateral) space, moving centripetally or centrifugally. The subjects showed a spatial effect, perceiving the same length as shorter in proximal space than distal space. This result could be related to either a proximal spatial attentional bias or an anisometric representation of spatial distances. In Experiment 2, we attempted to dissociate these hypotheses by studying blindfolded normal subjects, who were requested to produce horizontal lines of a given length (100 or 200 mm) in proximal versus distal peripersonal space using centripetal or centrifugal movements. Centrifugal movements in proximal space were the longest; centrifugal movements in distal space were the shortest: in between were the proximal centripetal and distal centripetal movements which did not differ from each other. These results suggest that in peripersonal space the perception of length in normal subjects is most consistent with anisometric mental representation where the size of mental representations of length units decreases as a function of the distance from the subject's midsagittal plane. Length production, however, may depend on an interaction of the anisometric mental representation and the premotor/intentional factors.
我们研究了正常受试者对给定线段长度的感知或生成是否会根据线段在个人周边空间中被感知或生成的位置而变化。我们还研究了用于绘制线段的移动方向的影响。在实验1中，蒙住双眼的正常受试者被要求估计距离，同时检查者在近端（内侧）或远端（外侧）空间中移动受试者的手，向心或离心移动。受试者表现出空间效应，即感知到相同长度在近端空间比在远端空间更短。这一结果可能与近端空间注意力偏差或空间距离的非等距表征有关。在实验2中，我们试图通过研究蒙住双眼的正常受试者来区分这些假设，这些受试者被要求使用向心或离心运动在近端与远端个人周边空间中绘制给定长度（100或200毫米）的水平线。近端空间中的离心运动最长；远端空间中的离心运动最短：介于两者之间的是近端向心运动和远端向心运动，它们彼此没有差异。这些结果表明，在个人周边空间中，正常受试者对长度的感知最符合非等距心理表征，即长度单位的心理表征大小随着与受试者正中矢状面距离的增加而减小。然而，长度生成可能取决于非等距心理表征与运动前/意向因素的相互作用。
