Effects of exposure time and intertrial interval upon decrement to the Müller-Lyer illusion.

Abstract

Decrement in magnitude of constant error to the Miiller-Lyer figure was reported to occur as a function of trials early in this century (3,5,6,11). Recently interest in this phenomenon has been revived (7,8,9). Kohler and Fishback (7,8) reported: an inverse relationship between number of trials per day and magnitude of decrement; greater decrement with spaced trials; additional decrement during overnight rest periods. Preliminary research (12) failed to verify these relationships and suggested alternative hypotheses. Decrement in magnitude of a response as a function of trials has long been referred to in the field of learning as "habituation" (4). If the change in response to the Muller-Lyer figure is an habituatory decrement, it is related to experimental variables in the same manner as 1 This paper is based upon a dissertation submitted to the Graduate School of Indiana University in partial fulfillment of the requirements for the Ph.D. degree. The author is indebted to J. R. Kantor, W. K. Estes, and H. G. Yamaguchi for many helpful suggestions during the course of this study.

Apparent combined length of two-line and four-line sets

“…8 (4) Unequally long pairs in the 25/75 to 35/65 range looked longer than 50/50 pairs in Experiments I, 2, and 3, and the strength of this illusion may depend on exposure duration. When S views a geometrical illusion for a longer duration or for a larger number of repeat exposures, the illusion typically diminishes (e.g., Lewis, 1912;Mountjoy, 1958;Schiller & Wiener, 1962). Piaget, Bang, and Matalon (1958), for instance, found maximums for various illusions at tachistoscopic exposures ranging from 0.04 to 0.5 sec, with the most typical maximum occurring at 0.1 sec.…”

Illusion decrement in intersecting line figures

“…The occurrence of decrement in the magnitude of the Mueller-Lyer illusion is, however, weIl established (Judd, 1902;Lewis, 1908;Mountjoy, 1958;Day, 1962). Although the reasons for the decrease in illusion magnitude with practice are not yet clear, there are indications that information from erroneous saccadic eye movements made during inspection of the figure facilitates the process (Festinger, White, & Allyn, 1968;Burnham, 1968).…”

Peripheral and central components in variants of the Mueller-Lyer illusion

“…1902): (2) rate of decrement responds to traditional learning variables such as the spacing of trials (Dewar. 1968: Mountjoy. 1958): and (3) the amount of decrement is increased if information about the nature and extent of the iIlusion is made available through information feedback from erroneous eye movements over the figure (Coren & Hoenig.…”