Can patients with central field loss perform head pointing in a virtual reality environment?

International audienceIntroduction: Virtual Reality (VR) headsets are raising more and more interest from the low-vision research community since they offer a promising framework for low-vision aids and rehabilitation protocols. However, the study of VR accessibility to low vision is still in its early stages and designing efficient user interfaces for low-vision users remains an open challenge. Head pointing (a common way to interact with the world in VR environments) may represent a promising option for patients with Central Field Loss (CFL) who lose the ability to direct their gaze efficiently towards a target. Yet, little is known about the actual head-pointing capacities of CFL patients.Discussion: The purpose of the current study is to evaluate whether patients with CFL are able to perform precise head-pointing tasks in VR. 49 patients with binocular CFL, aged 34 to 97 (mean = 77±13), were tested with an Oculus Go headset in a very simple VR environment (grey background). At the beginning of each block, a head-contingent reticle was displayed in a specific location in front of the patient. A total of 9 reticle locations were tested either in the center of the visual field or with a 7° offset. At each trial, a target appeared in the visual field and patients were instructed to move their head to position the reticle precisely onto the target. Targets were black circles (1° to 3° diameter) randomly presented in five fixed positions (center or top, right, bottom, left at 18° of eccentricity). On average, patients were able to use their head to position the reticle precisely onto the target 94% of the time. Individual differences emerged, with a significant drop in pointing speed performance for specific reticle locations.Conclusions: Our preliminary results show that patients with CFL are able to perform accurately precise head-pointing tasks. This represents a fundamental step towards the design of efficient and user-friendly visual aids and rehabilitation tools using VR. For instance, head pointing could provide an ergonomic framework to design user interfaces that require precise pointing abilities to perform item selection. Similarly, one can imagine designing head-contingent pointing exercises that will drive the rehabilitation process while limiting straining of the eyes

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Pointing at static targets in a virtual reality environment: performance of visually impaired vs. normally-sighted persons

International audienceVirtual reality (VR) offers innovative perspectives in the field of visual impairment. The general and exploratory goal of this study was to investigate how well the patients performed a pointing task compared to normally-sighted controls. We also assessed whether the characteristics of patients’ scotoma correlated with their performance in our pointing task. Normally-sighted and visually impaired subjects participated in a head contingent task developed with PTVR (https://ptvr.inria.fr/). Subjects had to move their head to point with a head-contingent reticle at a static target in the virtual environment. Pointing had to be maintained for 2 seconds to be validated (a timeout occurred after 30 sec without valid pointing). Reticle position in the headset’s viewport was either in the center (centered condition) or 10° from the center at one of the 8 possible half-meridians (eccentric condition). An additional perimetric exam was conducted for patients using a microperimeter (MP-3 Nidek Inc.), thus providing information about the position and shape of the scotoma. Our main dependent variable was the time needed to achieve valid pointing. We also estimated the accuracy of the subjects’ performance. Accuracy is the percentage of trials validated by the subject during the experiment. Linear mixed-effects models were used to analyze the reaction times of all subjects. Our preliminary data (N=8) show that visually impaired subjects are able to perform our head-contingent task. Although the reaction times were longer in the patients’ group (mean, 12.4 sec) than in the control group (mean, 4.6 sec). Patients had lower accuracy (87%) than normally-sighted subjects (100%). For the patients’ group, the results indicate an anisotropy of pointing performance across the reticle’s positions. Microperimetry data will help to understand how this idiosyncratic anisotropy may be related to the characteristics of each subject's scotoma. These data will help us develop rehabilitation tools based on pointing tasks

Influence of logographic and alphabetic writing systems on auditory information processing: The generalizability and stability issues

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Pointing at static targets in a virtual reality environment: performance of visually impaired vs. normally-sighted persons

International audienc

Can patients with central field loss perform head pointing in a virtual reality environment?

International audienceIntroduction: Virtual Reality (VR) headsets are raising more and more interest from the low-vision research community since they offer a promising framework for low-vision aids and rehabilitation protocols. However, the study of VR accessibility to low vision is still in its early stages and designing efficient user interfaces for low-vision users remains an open challenge. Head pointing (a common way to interact with the world in VR environments) may represent a promising option for patients with Central Field Loss (CFL) who lose the ability to direct their gaze efficiently towards a target. Yet, little is known about the actual head-pointing capacities of CFL patients.Discussion: The purpose of the current study is to evaluate whether patients with CFL are able to perform precise head-pointing tasks in VR. 49 patients with binocular CFL, aged 34 to 97 (mean = 77±13), were tested with an Oculus Go headset in a very simple VR environment (grey background). At the beginning of each block, a head-contingent reticle was displayed in a specific location in front of the patient. A total of 9 reticle locations were tested either in the center of the visual field or with a 7° offset. At each trial, a target appeared in the visual field and patients were instructed to move their head to position the reticle precisely onto the target. Targets were black circles (1° to 3° diameter) randomly presented in five fixed positions (center or top, right, bottom, left at 18° of eccentricity). On average, patients were able to use their head to position the reticle precisely onto the target 94% of the time. Individual differences emerged, with a significant drop in pointing speed performance for specific reticle locations.Conclusions: Our preliminary results show that patients with CFL are able to perform accurately precise head-pointing tasks. This represents a fundamental step towards the design of efficient and user-friendly visual aids and rehabilitation tools using VR. For instance, head pointing could provide an ergonomic framework to design user interfaces that require precise pointing abilities to perform item selection. Similarly, one can imagine designing head-contingent pointing exercises that will drive the rehabilitation process while limiting straining of the eyes