Depth Cue Conflicts Between Real and Virtual Objects Disrupt Visually-Guided Reaching in Augmented Reality.

Depth cues, such as binocular disparity, play a critical role in supporting accurate and precise reaching within near space, facilitating reliable interaction with objects and surfaces [27]. Augmented reality (AR) presents unique challenges for such interactions, as mismatched focal distances between real and virtual objects can distort perceived depth. Prior work has examined the perceptual consequences of focal distance mismatches under controlled viewing conditions, as well as AR task performance in more natural settings; here we consider these factors together in a visually guided reaching task with multiple available depth cues for combinations of real and virtual objects. Participants performed a precision visual motor task in an AR environment, placing a virtual ring around either real or virtual posts at varying distances. Our results show that accuracy was degraded when placing a virtual ring on real posts, with fewer successful placements compared to virtual posts. We demonstrate that this increase in error was due to a systematic underestimation of virtual object distances relative to their physical counterparts. These findings indicate that distortions in perceived depth between real and virtual objects persist during active reaching, despite the availability of multiple depth cues including binocular disparity, proprioception, occlusion, and motion parallax. Measuring and correcting for these distortions is important for optimizing the effectiveness and usability of AR devices.