Objective. Retinal prostheses hold the potential to restore artificial vision in blind patients suffering from outer retinal dystrophies. The optimal number, density and coverage of the electrodes that a retinal prosthesis should have to provide adequate artificial vision in daily activities is still an open question and an important design parameter needed to develop better implants. Approach. To address this question, we investigated the interaction between the visual angle, the pixel number and the pixel density without being limited by a small electrode count. We implemented prosthetic vision in a virtual reality environment in order to simulate the real-life experience of using a retinal prosthesis. We designed four different tasks simulating: object recognition, word reading, perception of a descending step and crossing a street. Main results. The results of our study showed that in all the tasks the visual angle played the most significant role in improving the performance of the participant. Significance. The design of new retinal prostheses should take into account the relevance of the restored visual angle to provide a helpful and valuable visual aid to profoundly or totally blind patients.

In complex manufacturing a considerable amount of resources is focused on training workers and developing new skills. Increasing the effectiveness of those processes and reducing the investment required is an outstanding issue. In this paper, we present an experiment (n = 20) that shows how modern metaphors such as collaborative mixed reality can be used to transmit procedural knowledge and could eventually replace other forms of face-to-face training. We implemented a mixed reality setup with seethrough cameras attached to a Head-Mounted Display. The setup allowed for real-time collaborative interactions and simulated conventional forms of training. We tested the system implementing a manufacturing procedure of an aircraft maintenance door. The obtained results indicate that performance levels in the immersive mixed reality training were not significantly different than in the conventional face-to-face training condition. These results and their implications for future training and the use of virtual reality, mixed reality, and augmented reality paradigms in this context are discussed in this paper.

Virtual Reality (VR) has been widely applied to cultural heritage such as the reconstruction of ancient sites and artifacts. It has hardly been applied to the reprise of specific important moments in history. On the other hand immersive journalism does attempt to recreate current events in VR, but such applications typically give the viewer a disembodied non-participatory role in the scene of interest. Here we show how VR was used to reconstruct a specific historical event, where a famous photograph was brought to life, showing Lenin, the leader of the 1917 October Russian Revolution, giving a speech to Red Army recruits in Moscow 1920. We carried out a between groups experimental study with three conditions: Embodied-where the participant was first embodied as Lenin and then later in the audience watching Lenin; Included-where the participant was not embodied as Lenin but was embodied as part of the audience; and Observing-where the participant mainly viewed the scene from a disembodied third person point of view. Twenty participants were assigned to each of the three conditions in a between-groups design. We found that the level of presence was greatest in the Embodied and Included conditions, and that participants were least likely to later follow up information about the Russian Revolution in the Observing condition. Our conclusion is that if the VR setup allows for a period of embodiment as a character in the scenario then this should be employed in order to maximize the chance of participant presence and engagement with the story.