Abstract
According to the action-specific perception account, perception of space is influenced by the energetic costs required to perform an action. As a result, action abilities are restricted by the physical characteristics and limitations of the perceiver. As such, changes in an observer’s reaching ability (Witt et al., 2005) or the ability to pass through an aperture (Stefanucci & Geuss, 2009) have an effect on perceived space, such as distance and width. Other work has also demonstrated that perceived hill slant is influenced by one’s ability to walk up a hill; hills appeared steeper to people carrying a heavy backpack, those who are elderly or in poor physical fitness (Bhalla & Proffitt, 1999). However, these experiments have not made the distinction in terms of whether action-specific effects are influenced by actual ability and/or beliefs about ability. In the current experiment, we examined the effect of obesity on perceived hill slant. Among people who struggle with obesity, there exists a naturally occurring dissociation between beliefs about body size and actual body size (Truesdale & Stevens, 2008). Seventy-three subjects of various weight classification groups, including normal weight, overweight and obese, made visual estimates of the slant of a hill. Participants also provided evaluative, perceptual and self-report measures of their beliefs about body size as well as actual body size measurements such as weight, body mass index (BMI), and percent body fat. We found that actual body size influenced perceived hill slant such that greater BMI, body fat, and weight resulted in larger visual hill slant estimates. Furthermore, we found that beliefs about body size do not affect perceived slant, illustrating that perceived space is influence by an observer’s actual body size regardless of a person’s beliefs about body size.
Meeting abstract presented at VSS 2013