Comparison of figural aftereffect and figural retroactive-effect for the concentric circles figure.

Abstract

The concentric circles figural aftereffect (FAE) and figural retroactive-effect (FRE) have been compared for different luminance contrast and temporal conditions (Adam, Heron, & Cooper, 1972; Adam, Mullin, & Sperry, 1969). This paper reports a comparison of the two phenomena for six diameters of the inducing figure, these ranging from four-tenths to nine-tenths of a standard 1.25-in. test figure diameter. Stimuli were drawn in black on white cards and presented tachistoscopically at a distance of 52 in. Both figures were 1.25 in. to S's left from a fixation point while comparison figures were the same distance to the right. Exposure durations of the inducing and test figures were 50 msec. and 200 msec. respectively, the second stimulus (test figure for FAE, inducing figure for FRE) immediately following the first (inducing figure for FAE, test figure for FRE). Two independent groups of 10 Ss each were used for measurement of the FAE and FRE, each S making judgments for all diameters of inducing figures. Other details of experimental method were essentially the same as those used in the earlier comparisons of FAE and FRE, and in previous FAE studies reported in This Journal (e.g., Adam & Ring, 1968). The FAE consistently displayed the typical apparent repulsion of test figure by the inducing figure. In the raw data for the FRE, however, a number of attraction effects were evident, these occurring most frequently when the ratio between diameters of the inducing and test figures was 8:lO. These attraction effects were replicated for a new group of 10 Ss and persisted when Ss were retested after an interval of one to two days. Conditions for their occurrence are currently under investigation.