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Christopher Kuylen, Laura Thomas, Ben Balas; Cast-body shadows compress perceived distances. Journal of Vision 2013;13(9):214. doi: https://doi.org/10.1167/13.9.214.
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© ARVO (1962-2015); The Authors (2016-present)
When people use a tool to interact with a distant object, the tool can serve as an extension of the human body, leading observers to perceive the object as significantly closer to them (e.g., Davoli et al., 2012). Another entity that may function as an extension of the human body is the cast-body shadow. Although observers cannot use shadows to manipulate objects, they do extend from an observer’s body and create visual changes in the area beyond peripersonal space. We investigated the influence of cast-body shadows on distance perception. Participants (N = 9) viewed an athletic cone at one of eight randomized distances (20’-55’) in three experimental conditions: (1) while shining a laser pointer on the athletic cone, (2) while a light projected their cast-body shadow towards the athletic cone, (3) and under a control condition. Participants then estimated the distance to the cone by turning away, watching the experimenter walk, and telling the experimenter to stop when they thought he was the same distance away as the previously viewed athletic cone. Participants’ distance estimations of the cone were significantly shorter in both the laser and shadow conditions than in the control condition (p<0.005 in each case), but the laser and shadow conditions did not differ from each other (p=0.50). This demonstrates that, like tools, shadows serve as an extension of the body, leading to an underestimation of perceived distance. The results add new support to the hypothesis that extensions of the human body can perceptually distort space and indicate that cast-body shadows are perceived as part of the observer’s body representation and may thus influence a wider range of perceptual phenomena.
Meeting abstract presented at VSS 2013
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