Adam Barnas, Kevin Longacre



Download Project (1.2 MB)


The embodied cognition approach to perception suggests that spatial perception involves the integration of visual cues and body-based cues when perceiving capabilities for action, or affordances, in extrapersonal space. For example, behavioral studies suggest that altering the affordances of the observer (e.g., by giving the participant a tool to extend reach) alters the perceived body size (peripersonal space) and perceived dimensions of the environment (extrapersonal space), such as the perceived distance to a target (Reed & Farah, 1995). Eye height is also likely to play a role in judging object dimensions, the perception of affordances, and other action capabilities (Warren & Whang, 1987). Studies recording participants' performances walking under a series of obstacles show that people require a larger margin of safety when wearing an apparatus on their head or feet that increases their physical height because of the unfamiliarity of the adopted body dimensions. Across three experiments, we will utilize several measures to examine the effect of body height and eye height on perceived object height and perceived passability through a vertical aperture in extrapersonal space. To this end, we hypothesize that body height and eye level manipulations will ultimately alter the perception of the observer's environment, such as reporting smaller object sizes and more difficult passability. All three experiments require participants to match the height of several vertical apertures and report whether they could walk through the apertures without ducking or touching the top. Experiment 1 will serve as a control since body height and eye level will not be manipulated. Experiment 2 will manipulate body height by using rods of varying lengths and Experiment 3 will manipulate eye level by having participants stand on platforms of varying heights. These studies will demonstrate the importance of body dimensions in perceiving external space and affordances with vertical apertures.

Publication Date


Project Designation

Independent Research

Primary Advisor

Benjamin R. Kunz

Primary Advisor's Department



Stander Symposium project

The Influence of Personal Height and Eye Level on the Perception of Object Dimensions and Affordance Judgments