Greene Ernest
Department of Psychology, University of Southern California, Los Angeles, CA 90089-1061, USA.
Percept Mot Skills. 2007 Jun;104(3 Pt 2):1043-59. doi: 10.2466/pms.104.4.1043-1059.
Most extant theories of shape perception assume or assert that various contour attributes, and in particular, the orientation, curvature and linear extent of the contours provide essential object recognition cues. The present study examined this proposal using discrete dots that marked locations on the outer boundary of namable objects, providing shape-patterns similar to silhouettes. For each shape, the display initially provided only a sampling of the total number of dots in the boundary, and the number of dots was periodically increased until the participant named the object. There were three treatment conditions in which the initial display as well as the periodic increments consisted of continuous arrays (strings) of dots, randomly positioned dots, or evenly spaced dots. Analysis showed objects were recognized with the fewest percentage of dots with the evenly spaced condition, and participants needed the greatest percentage with the contiguous array condition. In many cases objects could be identified when very few evenly spaced dots were shown, thereby providing large spacing between the dots. It seems unlikely that known neural mechanisms could extract contour attributes, e.g., orientation, curvature, and linear extent, from such sparse stimulus patterns, which provides a challenge to the proposition that these are essential shape cues.
大多数现存的形状感知理论假定或断言，各种轮廓属性，特别是轮廓的方向、曲率和线性范围提供了基本的物体识别线索。本研究使用离散的点来检验这一观点，这些点标记了可命名物体外边界上的位置，提供了类似于剪影的形状模式。对于每个形状，显示最初只提供边界上总点数的一个样本，并且点数会定期增加，直到参与者说出物体的名称。有三种处理条件，其中初始显示以及定期增加的点数由连续的点阵列（串）、随机定位的点或均匀间隔的点组成。分析表明，在均匀间隔条件下，用最少百分比的点就能识别物体，而在连续阵列条件下，参与者需要最大百分比的点。在许多情况下，当显示很少的均匀间隔的点时就能识别物体，从而在点之间提供了很大的间距。已知的神经机制似乎不太可能从如此稀疏的刺激模式中提取轮廓属性，例如方向、曲率和线性范围，这对这些是基本形状线索的观点提出了挑战。
