Abstract
Previous research has shown that changing the body can influence the perception of distances in near space (Witt, Proffitt, & Epstein, 2005). In this set of experiments, we found that changes in body size altered the perception of the width of an aperture. In Experiment 1, participants were randomly assigned to either hold a large exercise ball or not. All participants' perception of the width of the apertures was assessed using a visual matching measure. Those participants who held the exercise ball estimated the width of the aperture to be smaller than those who were not holding the ball. In Experiment 2, we asked participants to perform the same task, but this time their body size was altered by wearing a different object, a 45-inch rod that extended across the participants' bodies. In contrast to the previous findings, participants who wore the rod overestimated the size of the aperture compared to participants who did not wear the rod. In Experiment 3, we assessed whether the perception of body size was accurate when holding the exercise ball and the rod. A group of participants estimated the width of their bodies (when holding the ball, when holding the rod, and when holding nothing) by visually estimating their width with a matching task and by drawing a representation of their width on a white board. Findings showed that participants overestimated their width when holding the ball and underestimated their width when holding the rod. The results suggest that the perception of body size plays a role in the estimation of the width of apertures and that the direction of change is dependent on participant's perception of their width when holding different sized objects.