Title

Are independent perceptions of weight and size possible by dynamic touch?

Date of Completion

January 1996

Keywords

Psychology, Experimental|Psychology, Cognitive

Degree

Ph.D.

Abstract

Most accounts of the size-weight illusion assume that perceptions of weight and size are not independent. A series of five experiments was conducted in order to formally evaluate this assumption. A perceptual-coupling hypothesis was rejected in Experiment 1 by demonstrating a lack of correlation between volume and perceived heaviness. An overall decrease in perceived heaviness accompanying all increases in volume was shown in Experiment 2, however, when participants were allowed to view the objects that they were hefting and wielding. The relations between the various perceptions of weight and size and the same physical dimensions were evaluated in Experiment 3. Perceived weight, length, and width were shown to be structured only by the appropriate physical variables whereas perceived volume was not independent of mass. This contrasts slightly with the true test of perceptual independence in Experiment 4 that demonstrated a perceptual independence of weight from length and volume. No conclusions were possible regarding the perceptual independence of weight and width. It was shown in Experiment 5 that observed independence and dependence was the result of particular information-perception relations. Independent perceptions are the result of independent information. Discussion focused on the roles of selective attention and motor control in this process. ^