Department of Computer Science

Central and peripheral vision loss, caused by conditions such as age-related macular degeneration and retinitis pigmentosa, disrupt visual processing in distinct ways, yet their impact on real-world scene perception remains poorly understood. Here, we used a real-time, gaze-contingent simulation to examine how central vision loss and peripheral vision loss alter eye movements and scene understanding. Sighted participants (n = 32, five males) viewed 120 real-world scenes (50% social interaction, 50% neutral) under one- or three-saccade constraints and described each scene; description quality was quantified via semantic similarity to ground-truth responses. Peripheral vision loss observers produced significantly less informative descriptions than both central vision loss and control participants, particularly for social interaction scenes, suggesting that peripheral vision is critical for rapid extraction of scene semantics. In contrast, central vision loss primarily disrupted oculomotor behavior, including increased saccade amplitudes, delayed saccade initiation, and reduced intersubject fixation consistency. Description quality was not predicted by fixation similarity to controls but by fixations to labeled humans and critical objects, underscoring the role of semantically informative sampling for real-world scenes that include people. These results reveal a dissociation between perceptual and oculomotor consequences of vision loss and highlight the importance of peripheral input for real-world scene understanding.

Purpose

Methods

Results

Conclusions

Translational relevance

A key limitation shared by both electronic and optogenetic sight recovery technologies is that they cause simultaneous rather than complementary firing within on- and off-center cells. Here, using "virtual patients"-sighted individuals viewing distorted input-we examine whether gamified training improves the ability to compensate for distortions in neuronal population coding. We measured perceptual learning using dichoptic input, filtered so that regions of the image that produced on-center responses in one eye produced off-center responses in the other eye. The Non-Gaming control group carried out an object discrimination task over five sessions using this filtered input. The Gaming group carried out an additional 25 hours of gamified training using a similarly filtered variant of the video game Fruit Ninja. Both groups showed improvements over time in the object discrimination task. However, there was no significant transfer of learning from the "Fruit Ninja" task to the object discrimination task. The lack of transfer of learning from video game training to object recognition suggests that gamification-based rehabilitation for sight recovery technologies may have limited utility and may be most effective when targeted on learning specific visual tasks.

Objective:Spatial scheduling of electrode activation ("rastering") is essential for safely operating high-density retinal implants, yet its perceptual consequences remain poorly understood. This study systematically evaluates the impact of raster patterns, or spatial arrangements of sequential electrode activation, on performance and perceived difficulty in simulated prosthetic vision (SPV). By addressing this gap, we aimed to identify patterns that optimize functional vision in retinal implants. Approach:Sighted participants completed letter recognition and motion discrimination tasks under four raster patterns (horizontal, vertical, checkerboard, and random) using an immersive SPV system. The simulations emulated epiretinal implant perception and employed psychophysically validated models of electrode activation, phosphene appearance, nonlinear spatial summation, and temporal dynamics, ensuring realistic representation of prosthetic vision. Performance accuracy and self-reported difficulty were analyzed to assess the effects of raster patterning. Main results:The checkerboard pattern consistently outperformed other raster patterns, yielding significantly higher accuracy and lower difficulty ratings across both tasks. The horizontal and vertical patterns introduced biases aligned with apparent motion artifacts, while the checkerboard minimized such effects. Random patterns resulted in the lowest performance, underscoring the importance of structured activation. Notably, checkerboard matched performance in the "No Raster" condition, despite conforming to groupwise safety constraints. Significance:This is the first quantitative, task-based evaluation of raster patterns in SPV. Checkerboard-style scheduling enhances perceptual clarity without increasing computational load, offering a low-overhead, clinically relevant strategy for improving usability in next-generation retinal prostheses.

Spatial memory and navigation are foundational cognitive functions intricately tied to the hippocampal and striatal neural circuits. These regions integrate multisensory inputs from the environment, with the vestibular system exerting a particularly strong influence on visuospatial processing. While prior work has explored how Galvanic Vestibular Stimulation (GVS) can enhance spatial cognition in individuals with vestibular disorders, limited research has focused on its potentially beneficial effects in those without vestibular disorders. To address this gap, we present a study using a novel experimental paradigm that combines noisy GVS (nGVS) with virtual reality (VR) to systematically examine the impact of vestibular stimulation on spatial learning and memory in healthy adults. Our findings (n=32) suggest that nGVS can significantly improve spatial memory performance, facilitating learning and recollection compared to the without-nGVS condition. Unlike previous screen-based studies, our work uniquely integrates nGVS with an ecologically valid scenario in VR, with study results indicating nGVS as a potential modifier of human spatial memory.

People who are blind employ unique strategies when performing instrumental activities of daily living (iADLs), often relying on multiple sensory modalities and assistive technologies. While prior research has extensively explored adaptive strategies for outdoor activities like wayfinding and navigation, less emphasis has been placed on the information needs and problem-solving strategies for managing domestic activities. To address this gap, our study presents insights from 16 semi-structured interviews with individuals who are either legally or completely blind, highlighting both the current use and potential future applications of technologies for home-based iADLs. Our findings reveal several underexplored challenges, including the difficulty of locating misplaced objects, a structured problem-solving approach where digital tools are a last resort, and limited awareness of assistive training programs. Participants also faced persistent usability barriers as software updates disrupted accessibility features. Participants utilize a variety of low-tech and high-tech solutions, with tactile labeling systems and digital assistance apps being particularly prevalent. However, existing assistive technologies often fail to integrate seamlessly with users’ preferred strategies, leading to frustration and underutilization. Addressing these barriers is crucial for enhancing the adoption of assistive technologies and ultimately improving the quality of life for people who are blind.

Purpose: Visual prosthetics are a promising assistive technology for vision loss, yet research often overlooks the human aspects of this technology. While previous studies focus on the perceptual experiences or attitudes of implant recipients (implantees), a systematic account of how current implants are being used in everyday life is still lacking. Methods: We interviewed six recipients of the most widely used visual implants (Argus II and Orion) and six leading researchers in the field. Through thematic analyses, we explored the daily usage of these implants by implantees and compared their responses to the expectations of researchers. We also sought implantees' input on desired features for future versions, aiming to inform the development of the next generation of implants. Results: Although implants are designed to facilitate various daily activities, we found that implantees use them less frequently than researchers expect. This discrepancy primarily stems from issues with usability and reliability, with implantees finding alternative methods to accomplish tasks, reducing the need to rely on the implant. For future implants, implantees emphasized the desire for improved vision, smart integration, and increased independence. Conclusions: Our study reveals a significant gap between researcher expectations and implantee experiences with visual prostheses. Although limited by access to a small population of implantees, this study highlights the importance of focusing future research on usability and real-world applications. Translational Relevance: This retrospective qualitative study advocates for a better alignment between technology development and implantee needs to enhance clinical relevance and practical utility of visual prosthetics.