Abstract
Although there has been a great deal of research on binocular distance perception (Foley, 1980; Gogel, 1977), a number of questions remain unexplored. One such question involves how our ability to perceive distances is influenced by fitness and stress (internal and external), a combination of task demands and factors often encountered by first responders. Previous research has shown that kinesthetic stress (via backpack weight) influences a person's ability to accurately judge distances (Proffitt, Bhalla, Gossweiler, & Midgett, 2003). In the current study, we both attempted to replicate and extend on previous work by exploring the effects of cardiovascular fitness (CVF) and anxiety on distance perception. Anxiety was measured using the State-Trait Anxiety Inventory test (Spielberger, Reheiser, & Sydeman, 1995) and CVF was measured using MET scores (Jurca et al., 2005). Participants were asked to verbally estimate distances and then walk blindly to the target while carrying a backpack weighing approximately 20% of their weight, which served as a physical stressor. We found that participants overestimated in the verbal task, but underestimated in the blind walking task, regardless of whether they wore a backpack or not. Interestingly, errors were approximately twice as large in the verbal task compared to the blind walking task as distance increased. Verbal judgment error was strongly, positively correlated between blocks, but blind walking was not, suggesting that the action oriented task (blind walking) may have been more sensitive to stress. Furthermore, there was a positive correlation between CVF and blind walking error for the second block of the heavy backpack condition, but not for the verbal error. Combined, our data support the assertion that verbal and action oriented tasks may be subserved by different neurophysiological networks (Bingham & Pagano, 1998).
Meeting abstract presented at VSS 2014