Charras Pom, Lupiáñez Juan
Departamento de Psicología Experimental y de Fisiología del Comportamiento, Campus de Cartuja S/N, CP 18071, Granada, Spain.
Perception. 2009;38(10):1428-38. doi: 10.1068/p6287.
The length of a whole line is overestimated in comparison to the sum of its parts (Künnapas, 1955 Journal of Experimental Psychology 49 134-140). This has been considered to be true for many years, although recent studies have demonstrated that it is not always so. The perception of the length of a whole line is highly dependent on the configuration of its two parts. More precisely, whereas a whole line is perceived as longer than the sum of symmetrically bisected line parts, this overestimation decreases when compared to the sum of the lengths of asymmetrically bisected line parts. Furthermore, the extent of overestimation depends on the degree of asymmetry, so that when the two parts are greatly asymmetric in length, the whole is no longer overestimated (Wolfe et al, 2005 Perception & Psychophysics 67 967-979). Here, two experiments are reported in which a vertical/horizontal line length comparison task was used to investigate how line bisection affects length estimation. The results give rise to a new general principle characterising the mechanisms of visual perception: the sum of the lengths of two asymmetrically bisected parts is perceived as greater than that of two symmetrically bisected parts. Also bisection plays a critical role in length perception by preventing vertical bias.
与各部分长度之和相比，整条线的长度被高估了（昆纳帕斯，1955年《实验心理学杂志》第49卷，第134 - 140页）。多年来人们一直认为情况确实如此，尽管最近的研究表明并非总是如此。整条线长度的感知高度依赖于其两部分的构型。更确切地说，当一条线被对称平分时，整条线被感知为比各部分长度之和更长，但与非对称平分的线部分的长度之和相比，这种高估就会减少。此外，高估的程度取决于不对称的程度，所以当两部分在长度上差异很大时，整体就不再被高估了（沃尔夫等人，2005年《知觉与心理物理学》第67卷，第967 - 979页）。这里报告了两个实验，其中使用垂直/水平线段长度比较任务来研究线段二等分如何影响长度估计。结果产生了一个表征视觉感知机制的新的一般原则：两个非对称平分部分的长度之和被感知为大于两个对称平分部分的长度之和。而且二等分通过防止垂直偏差在长度感知中起着关键作用。
