Theses and Dissertations Collection

Human perception of speed is heavily influenced by their distance from a ground plane. Previous studies have found that while controlling speed during simulated flight through an environment with both a ground plane and a plane of clouds above, humans naturally attend to speed information present in the ground plane only (Meyer, 2015). Potential factors leading to attentional selection of the ground plane under standard viewing conditions, known as ground dominance, include the direction of gravity, lower visual field bias, and the location of limbs (Dyre, Meyer, & Adamic, 2013). This experiment decoupled the direction of gravity from visual field and limb location by manipulating the posture of participants as either upright or supine. We continued to find evidence of altitude-speed cross-talk (confusing changes in altitude as changes in speed) in both the upright and supine conditions, providing evidence that gravity alone is not a determining factor on ground dominance.