REVERSIBILITY OF THE NECKER CUBE: III. EFFECTS OF INTERPOLATION ON REVERSAL RATE OF THE CUBE PRESENTED REPETITIVELY.

Abstract

The neuropsychological concept of satiation of orientation proposed to account for Necker cube reversals was examined. Under passive viewing, experiments were conducted (1) to compare reversal rates of the Necker cube presented to various parts of one or both retinas at a number of repetition rates, (2) to determine the effects of interpolating various related figures between successive exposures of the Necker cube, (3) to determine whether reversal rate of the Maltese cross, a figure-ground reversible figure, is similarly affected by varying repetition rate. The results indicated the following. (1) Reversal rates of Necker cube and Maltese cross were profoundly affected by varying repetition rate. This effect was independent of retinal locus. More reversals were mediated by the right than by the left hemisphere. (2) The interpolation Necker cube with axis of orientation similar to that of the test Necker cube had the effect of shifting the reversal rates toward that of continuous viewing even when there was no coincidence of the two cubes on the retina. The cube with axis of orientation opposite that of the test cube was ineffective. (3) Ipsilateral interpolation was more effective than contralateral interpolation in shifting the reversal rate toward that of the continuous case. (4) Since interpolation was quite effective when test cube was presented to one eye and interpolation cube to the contralateral eye, an explanation of reversals based upon retinal fatigue or related peripheral mechanisms is ruled out.