The perceived heaviness of non-visible wielded objects has been shown to be a function of the rotational inertia of the object…rdquo;the resistance the object offers to applied wielding torques (e.g., Amazeen & Turvey, 1996). However, when visual information about the object is available rotational inertia alone does not account for the perception of heaviness (e.g., Amazeen, 1997). Thus far, two visual influences on heaviness perception have been documented: Influences related to object size (i.e., larger objects are perceived as lighter than smaller objects; e.g., Ellis & Lederman, 1993) and those related to the kinematics of object motion (e.g., Runeson & Frykholm, 1981). Streit, Shockley, and Riley (2007b) established a link between rotational inertia and visual kinematic influences on heaviness perception demonstrating that changes in apparent rotational kinematics specified a change in rotational inertia, which, in turn, specified a change in multimodally-perceived heaviness. The nature of visual influences on heaviness perception remains unclear. Can purely visual kinematic and size influences on heaviness perception be understood in terms of an inertial model of heaviness perception? The present research was designed to evaluate the nature of visual influences on heaviness perception.
In two experiments, participants judged the heaviness of objects either multimodally (vision + dynamic touch) or visually (based on recordings of the wielding motion generated by multimodal perceivers) under manipulations of apparent object responsiveness and changes in rotational inertia (Experiment 1) or changes in apparent responsiveness and apparent size (Experiment 2). It was shown in Experiment 1 that visual heaviness perception was not reliably sensitive to changes in rotational inertia, but was to changes in apparent responsiveness. It was shown in Experiment 2 that both wielding kinematics and apparent size influenced visual heaviness perception. Specifically, heaviness perception increased with increased acceleration and decreased with increased apparent size. The results collectively suggest that both visual and multimodal heaviness perception may be sensitive to mulitmodally specified mass…rdquo;multimodally specified inertia (Streit et al., 2007b) scaled to the apparent dimensions of the wielded object.