Interocular conflict from a monocular augmented reality display: Impact of visual characteristics on performance.

In monocular see-through augmented reality systems, each eye is stimulated differently by a monocular image that is superimposed on the binocular background. This can impair binocular fusion, due to interocular conflict. As a function of visual characteristics, the latter can have a greater or lesser impact on user comfort and performance. This study tested several visual characteristics of a binocular background and a monocular element during an exposure that reproduced the interocular conflict induced by a monocular see-through near-eye display. The aim was to identify which factors impact the user's performance. Performance was measured as target tracking and event detection, identification, fixation time, and latency. Our results demonstrate that performance is a function of the binocular background. Furthermore, exogenous attentional stimulation, in the form of a pulse with different levels of contrast applied to the monocular display, appears to preserve performance in most background conditions.

Using the landmark-route-survey framework to evaluate spatial knowledge obtained from synthetic vision systems.

OBJECTIVE: Using the landmark-route-survey framework, this research investigated the effect of synthetic vision systems (SVS) in either low or high visibility conditions on performance in wayfinding and spatial-knowledge-based tasks that probed spatial awareness. BACKGROUND: SVS are cockpit displays that depict computer-generated views of the terrain surrounding an aircraft and have been developed to support flight efficiency through improved spatial awareness. No studies have directly measured SVS impact on the three levels of spatial knowledge (landmark, route, and survey). METHOD: A total of 55 nonpilots learned a route in four different experimental conditions (high or low visibility, either with or without SVS). Subsequently, they underwent four recall tasks: way finding, scene recognition, scene classification, and sketch map. Six dependent measures were used to probe the three levels of spatial knowledge (selection errors, sorting errors, number of landmarks depicted, bidimensional regression) and their use in the wayfinding task (direction errors, designated landmark errors, and wayfinding verbalized hesitations). RESULTS: SVS produced higher performance in all four tasks. The low visibility condition lowered the wayfinding and scene-recognition performance. CONCLUSION: The overall results indicated that visibility mostly affected the first level of spatial knowledge (landmark) inducing a decreased wayfinding performance, whereas the use of SVS influenced the three levels of spatial knowledge (route and survey) inducing an increased wayfinding performance. APPLICATION: Potential applications of this work include spatial knowledge-based measures to evaluate SVS prototypes as well as to assess the relationship between spatial knowledge and spatial awareness.