An experimental investigation of past experience as a determinant of visual form perception.

Abstract

Letters and reversed letters were intermingled in series with nonsense figures and presented both for 4 second exposures between the limits of 26 and 35° in indirect vision and for brief exposures of 60 or 20 ms. The differences between the reproductions of letters and reversed letters yielded significant critical ratios. However, when the series of stimulus figures were made up solely of letters or reversed letters, the difference in reproductions for letters and reversed letters was insignificant. It is suggested that the set in the first experiment was not truly neutral, but involved a positive set to see nonsense figures, which was the essential condition for the emergence of an experience effect. Additional experiments comprising geometrical forms that were structurally equivalent to letters and to their reversed forms yielded insignificant differences. "Likewise, Chinese and Arabic characters were no more readily perceived in obverse than in reverse orientation by subjects unfamiliar with them. Thus all the indications are that structural differences between letters and their reversals are not responsible for the difference in readiness of perception between them." (PsycINFO Database Record (c) 2006 APA, all rights reserved)