Studies in space orientation. III. Perception of the upright in the absence of a visual field.

Abstract

the position of his body varied systematically, the S, in a completely darkened room, was required to adjust a luminous rod to the true vertical and horizontal. Judgments were found to be very accurate when the body was upright, but errors appeared as soon as the body, or even the head alone, was titled. The largest errors occurred when the body was horizonal, which was the most extreme displacement of the body employed. In addition, when the body was tilted, successive judgments proved to be quite variable. It is thus indicated that postural factors provide an adequate and stable basis for judging the vertical and horizontal when the body is upright, but not when the body is tilted. The errors made with head or body tilted were systematic in their direction. With small tilts, the rod tended to be displaced opposite to the body, and with large tilts, toward the body. These are the long-know E-phenomenon and Aubert-phenomenon, respectively. These phenomena are eliminated at once upon the introduction of a visual field. (see 23: 48). (PsycINFO Database Record (c) 2012 APA, all rights reserved)