The growth of the equidistance tendency over time

To determine the manner in which the equidistance tendency (ET) varies as a function of time, 10 Ss tracked the perceived position of a monocular test object viewed in a binocular field consisting of two rectangles which differed in perceived size and distance.Variables investigated were the temporal order of rectangle appearance and disappearance which determined whether or not opposingETs existed, luminance and repetition interval of the 20 msec test object. It was found thatET effects occur gradually over time, that opposingETs retard the rate at which the test object changes its perceived locus, and that elapsed time rather than total observation time was critical in determining how great a change in perceived locus of the test object occurred. Implications of these findings were discussed.