Laws Keith R, Gale Tim M, Frank Ray, Davey Neil
Department of Psychology, London Guildhall University, United Kingdom.
Brain Cogn. 2002 Mar-Apr;48(2-3):421-4.
It has been argued that greater intra-category structural similarity for living things, and the subsequent "visual crowding," makes them more difficult to recognize and name for neurologically damaged individuals and normal subjects (Humphreys et al., 1988). Nevertheless, the precise meaning and quantification of structural similarity remains unclear, as does the rationale for why it necessarily should be greater for living things. We derived a new measure of visual overlap from the Snodgrass and Vanderwart corpus of line drawings: the degree of pixel overlap within subcategories (Euclidean distance: ED). Contrary to existing notions of visual crowding and extant measures of contour overlap, within-category ED indicated less within-category visual overlap for living things. Furthermore, musical instruments clustered with living things (having low overlap), while body parts clustered with nonliving things (having high overlap). These counter-intuitive findings accord with patient data and thus, provide evidence for the psychological reality and utility of ED.
有人认为，生物类别内部更高的结构相似性以及随之而来的“视觉拥挤”，使得神经受损个体和正常受试者更难识别和命名它们（汉弗莱斯等人，1988年）。然而，结构相似性的确切含义和量化仍不明确，同样不明确的还有为什么生物的结构相似性必然更高的理由。我们从斯诺德格拉斯和范德瓦特的线条画语料库中得出了一种新的视觉重叠度量：子类别内的像素重叠程度（欧几里得距离：ED）。与现有的视觉拥挤概念和轮廓重叠度量相反，类别内的ED表明生物的类别内视觉重叠较少。此外，乐器与生物归为一类（重叠度低），而身体部位与非生物归为一类（重叠度高）。这些与直觉相悖的发现与患者数据相符，因此为ED的心理现实性和实用性提供了证据。
