On the Go with AR: Attention to Virtual and Physical Targets while Varying Augmentation Density

TL;DR

This study examines how augmentation density and path guidance in on-the-go augmented reality affect attention, search performance, and memory during a walking task. Using a locomotion-based gem search with both physical and virtual targets and a moving spotlight, the authors quantify how clutter and guided navigation shape behavior and awareness of the environment. Key findings show that environmental clutter increases scanning and can reduce awareness of a salient object, with physical targets detected more reliably than virtual ones, while memory for physical and virtual items is similar but prone to source confusion. The work provides design guidance for AR-on-the-go applications, highlighting clutter reduction, safety-focused prioritization of physical cues, and personalized navigation to balance task performance with user comfort and safety.

Abstract

Augmented reality is projected to be a primary mode of information consumption on the go, seamlessly integrating virtual content into the physical world. However, the potential perceptual demands of viewing virtual annotations while navigating a physical environment could impact user efficacy and safety, and the implications of these demands are not well understood. Here, we investigate the impact of virtual path guidance and augmentation density (visual clutter) on search performance and memory. Participants walked along a predefined path, searching for physical or virtual items. They experienced two levels of augmentation density, and either walked freely or with enforced speed and path guidance. Augmentation density impacted behavior and reduced awareness of uncommon objects in the environment. Analysis of search task performance and post-experiment item recall revealed differing attention to physical and virtual objects. On the basis of these findings we outline considerations for AR apps designed for use on the go.

Figures (13)

• Figure 1: Four classes of gems encountered by participants. From left to right: Unmarked-Physical, Unmarked-Virtual, Marked-Physical, Marked-Virtual. All gems emit purple light, and the virtual gems were designed to closely resemble the physical gems.
• Figure 2: Participants experienced two levels of virtual augmentation (environmental clutter) in the hallway the experiment was conducted in. Images depict the environment with low (a) and high (b) levels of augmentation.
• Figure 3: Environment navigation. (a) A depiction of a participant walking within the "spotlight" ring - a virtual green ring that was used to guide participants' path through the study environment in the guided conditions. (b) An example of the spotlight from a participant's perspective (captured directly from the headset). (c,d) Heatmaps depicting the locomotive activity of all participants during spotlight-present (c) and spotlight absent (d) trials. Higher temperatures indicate increased dwell times.
• Figure 4: Twenty-five different light renderings were tested to create virtual gems that most resembled the physical gems. Eight of the twenty-five renderings are shown, with the second gem (from left ) in the top row being the most accurate and thus chosen for the study. The image shown was captured directly from Unity, not from the headset.
• Figure 5: Four different study conditions. Examples from the full factorial combination of augmentation (low, high) and spotlight (absent, present), which creates four distinct conditions. Condition order was fully counterbalanced, and participants completed two trials of each condition, resulting in a total of eight trials for each participant. The participant's perspective at the start of a trial is depicted in each of the images.