Evolved navigation theory and horizontal visual illusions

Evolved navigation theory and the plateau illusion

“…Data from a repeated-measures analysis of variance suggested significant differences between edge and ground estimates, F(1, 52) = 57.98, p < .001, a significant difference in magnitude across stimulus lengths, F(2, 104) = 15.58, p = .004, and no significant interaction between these two variables, F(2, 104) = 0.07, p = .934. This manipulation generally replicated the results of similar manipulations in previous research (Jackson, 2005(Jackson, , 2009Jackson & Cormack, 2007, 2008Jackson & Willey, 2011).…”

“…ground). Underestimation in order to increase safe navigation extends directly from the ENT concept of overestimation in order to decrease risky navigation outlined in previous literature (Jackson, 2005(Jackson, , 2009(Jackson, , 2013Jackson & Cormack, 2006, 2007, 2008Jackson & Willey, 2011). Although the visual setting of Experiment 1 did not generate a clear underestimation, we observed the expected underestimation across all expected distances in Experiment 2, plausibly generated by the presence of clear navigation risks.…”

“…This also required an egocentric toward estimate because an exocentric estimate would fall on the edge surface (see Figs. 1 and 3), which would replicate a different estimate and increase perceived distance (Jackson & Willey, 2011), which would bias results toward ENT predictions. In order to understand if egocentric or exocentric estimation method affected estimates, we were able to present both methods between subjects in all edge and ground estimates in Experiment 2 and compare participant estimates across those methods.…”

“…We conducted a manipulation check in order to determine if observers' estimates reflected falling risks, as demonstrated in similar research (Jackson, 2005;Jackson & Cormack, 2006, 2011. Specifically, that observers estimated distances without falling risks (e.g.…”

“…Further, Jackson (2009) found that observers who (unknowingly) most overestimate the length of surfaces from which they could fall also most overestimate the risk of falling. Jackson and Cormack (2010) found that removal of falling risk removes these overestimations, while Jackson and Willey (2011) found that adding falling risks to otherwise correctly estimated surfaces induces these overestimations. This ENT logic appears in print repeatedly and unambiguously over years prior to the current study.…”