The Effect of Feedback on Estimates of Reaching Ability in Virtual Reality

Immersive virtual environments (VEs) are most useful for training and education when viewers perceive and act accurately within them. Judgments of action capabilities within a VE provide a good measure of perceptual fidelity - the notion of how closely perception and action in the VE match that in the real world - and can also assess how perception for action may be calibrated with visual feedback based on one's own actions. In the current study we tested judgments of action capabilities within a VE for two different reaching behaviors: reaching out and reaching up. Our goal was to assess whether feedback from actual reaching improves judgments and if any recalibration due to feedback differed across reaching behaviors. We first measured participants' actual reaching out and reaching up capabilities so that feedback trials could be scaled to their actual abilities. Participants then completed blocks of alternating perceptual adjustment and feedback trials. In adjustment trials, they adjusted a virtual target to a distance perceived to be just reachable. In feedback trials, they viewed targets that were farther or closer than their actual reach, decided whether the target was reachable, and then reached out to the target to receive visual feedback from a hand-held controller. The first feedback block manipulated the target distance to be 30% over or under actual reach and subsequent blocks decreased the deviation to 20%,10% and 5% of actual reach. We found that for both reaching behaviors, reach was initially overestimated, and then perceptual estimations decreased to become more accurate over feedback blocks. Accuracy in the feedback trials themselves showed that targets just beyond reach were more difficult to judge correctly. This study establishes a straightforward methodology that can be used for calibration of actions in VEs and has implications for applications that depend on accurate reaching within VEs.