Nakamizo Sachio, Imamura Mariko
Department of Psychology, Faculty of Human-Environment Studies, Kyushu University, 6-19-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
J Physiol Anthropol Appl Human Sci. 2004 Nov;23(6):325-9. doi: 10.2114/jpa.23.325.
We examined Emmert's law by measuring the perceived size of an afterimage and the perceived distance of the surface on which the afterimage was projected in actual and virtual environments. The actual environment consisted of a corridor with ample cues as to distance and depth. The virtual environment was made from the CAVE of a virtual reality system. The afterimage, disc-shaped and one degree in diameter, was produced by flashing with an electric photoflash. The observers were asked to estimate the perceived distance to surfaces located at various physical distances (1 to 24 m) by the magnitude estimation method and to estimate the perceived size of the afterimage projected on the surfaces by a matching method. The results show that the perceived size of the afterimage was directly proportional to the perceived distance in both environments; thus, Emmert's law holds in virtual as well as actual environments. We suggest that Emmert's law is a specific case of a functional principle of distance scaling by the visual system.
我们通过测量后像的感知大小以及后像在实际环境和虚拟环境中所投射表面的感知距离，来检验埃默特法则。实际环境是一条有丰富距离和深度线索的走廊。虚拟环境是由虚拟现实系统的洞穴式自动虚拟环境（CAVE）构建而成。通过电子闪光灯闪烁产生直径为1度的圆盘状后像。要求观察者采用数量估计法估计位于不同实际距离（1至24米）的表面的感知距离，并采用匹配法估计投射在这些表面上的后像的感知大小。结果表明，在两种环境中，后像的感知大小与感知距离成正比；因此，埃默特法则在虚拟环境和实际环境中均成立。我们认为，埃默特法则是视觉系统距离缩放功能原理的一个具体实例。
