Multimodally specified energy expenditure and action-based distance judgments

Abstract

Previous research has demonstrated that perceived self-motion can be manipulated by the relation between optic flow rate and walking rate. Other studies have revealed that verbal reports of perceived distance are influenced by the energy that would be expended to traverse the distance in question. In an effort to integrate these findings, we investigated how action-based distance judgments are influenced by multimodally specified energy expenditure (MSEE)-the metabolic cost associated with traversing an optically specified distance-using a virtual-reality treadmill environment. The energy expenditure associated with walking, measured as the volume of oxygen consumed, was manipulated by changing treadmill speed or grade. Optically specified distance was manipulated by changing the virtual optic flow rate. All three manipulations of MSEE (walking rate, grade, and optic flow rate) influenced distance reports in the predicted directions and to equivalent degrees. decoupled optical information about forward self-motion from actual walking rate (and thus from proprioceptive information about forward motion) by having participants walk on a treadmill towed by a tractor. When the treadmill speed was slower than the tractor speed (optic flow suggested faster walking), participants underestimated a target distance when later asked to blind-walk it. Likewise, participants overestimated when the treadmill speed was faster than the tractor speed. This result was explained in terms of visuomotor calibration between optical and proprioceptive information about self-motion. KeywordsOther nonoptical influences on distance reports resist visuomotor calibration explanations. Energy expenditure influences prospective (verbal) distance reports even when environmental (i.e., optical) cues remain constant (Proffitt et al.,

Action potential influences spatial perception: Evidence for genuine top-down effects on perception

“…For example, on a regular treadmill, forward walking energy is paired with zero optic flow, so perceivers adapt to the relationship that it takes a lot of effort to go nowhere. Other novel pairings between walking energy and optic flow can be created by using virtual environments (Proffitt et al, 2003;White et al, 2013). Novel pairings can also be created through the clever technique of placing the treadmill on top of a trailer that is being pulled by a tractor (Rieser et al, 1995).…”

“…These studies used a treadmill to recalibrate anticipated walking effort (Proffitt et al, 2003;White, Shockley, & Riley, 2013;Witt et al, 2004;Witt, Proffitt, & Epstein, 2010). Participants walked on a treadmill for approximately 3-5 min.…”

“…Thus, to address the issue of whether walking energy impacts perceived distance, or merely judgments of distance, studies have been run using either verbal estimates (Proffitt et al, 2003;Witt et al, 2004) or measures for which no explicit judgment is made. Instead, participants estimate distance by reproducing the distance by blindwalking to the target (White et al, 2013;Witt, Proffitt, & Epstein, 2010).…”

Relationships and Health: The Critical Role of Affective Science

“…For example, physical fitness is negatively associated with perceived distance (Zadra, Weltman, & Proffitt, 2015) and higher percent body fat corresponds with greater perceived slant in staircases (Taylor-Covill & Eves, 2015). Ongoing energy expenditures (as when running on a treadmill) even correspond with steadily increasing distance judgments (White, Shockley, & Riley, 2013). In its incorporation of these findings, social baseline theory suggests that a key element of social relationships-at least in humans-is the assimilation of others into the self (Aron & Aron, 1997;Lane Beckes, Coan, & Hasselmo, 2013).…”

Optic flow is calibrated to walking effort

“…Given evidence that walkable extents are scaled by the bioenergetic costs of walking (Zadra, Weltman, & Proffitt, 2015;White, et al, 2013), walking energy rather than walking speed may also be the effective variable in the associative relationship between walking magnitude and optical flow magnitude. To test this hypothesis, we used a treadmill and virtual environment (Experiment 2) to manipulate the three relevant variables: (1) walking speed, (2) walking effort, and (3) optical flow speed (see Fig.…”