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Our internal sense of direction is thought to rely on the activity of head-direction (HD) neurons. We find that the mouse dorsal presubiculum (PreS), a key structure in the cortical representation of HD, displays a modular "patch-matrix" organization, which is conserved across species (including human). Calbindin-positive layer 2 neurons within the "matrix" form modular recurrent microcircuits, while inputs from the anterodorsal and laterodorsal thalamic nuclei are non-overlapping and target the "patch" and "matrix" compartments, respectively. The apical dendrites of identified HD cells are largely restricted within the "matrix," pointing to a non-random sampling of patterned inputs and to a precise structure-function architecture. Optogenetic perturbation of modular recurrent microcircuits results in a drastic tonic suppression of firing only in a subpopulation of HD neurons. Altogether, our data reveal a modular microcircuit organization of the PreS HD map and point to the existence of cell-type-specific microcircuits that support the cortical HD representation.

Virtual reality systems are a popular tool in behavioral sciences. The participants’ behavior is, however, a response to cognitively processed stimuli. Consequently, researchers must ensure that virtually perceived stimuli resemble those present in the real world to ensure the ecological validity of collected findings. Our article provides a literature review relating to distance perception in virtual reality. Furthermore, we present a new study that compares verbal distance estimates within real and virtual environments. The virtual space—a replica of a real outdoor area—was displayed using a state-of-the-art head-mounted display. Investigated distances ranged from 8 to 13 m. Overall, the results show no significant difference between egocentric distance estimates in real and virtual environments. However, a more in-depth analysis suggests that the order in which participants were exposed to the two environments may affect the outcome. Furthermore, the study suggests that a rising experience of immersion leads to an alignment of the estimated virtual distances with the real ones. The results also show that the discrepancy between estimates of real and virtual distances increases with the incongruity between virtual and actual eye heights, demonstrating the importance of an accurately set virtual eye height.

Background: The human resources required on large cruise ships can only be secured with crew members from different countries of origin with different health statuses. Method: The present secondary...

Objective: The goal of this contribution is to develop a classifier able to determine if cybersickness (CS) has occurred after immersion in a virtual reality (VR) scenario, based on a combination of biosignals and game parameters. Methods: We collected electrocardiographic, electrooculographic, respiratory, and skin conductivity data from a total of 66 participants. In addition, we also captured relevant game parameters such as avatar linear and angular speed as well as acceleration, head movements, and on-screen collisions. The data were collected while the participants were in a 10-minute VR experience, which was developed in Unity. The experience forced rotation and lateral movements upon the participants to provoke CS. A baseline was captured during a first simple scenario. The data were then split in per-level, per-60-second, and per-30-second windows. Furthermore, participants filled a pre- and postimmersion simulator sickness questionnaire. Simulator sickness scores were then used as a reference for binary (CS vs. no CS) and ternary (no CS-mild CS-severe CS) classification patterns. Several classification methods (support vector machines, K-nearest neighbors, and neural networks) were tested. Results: A maximum classification accuracy of 82% was achieved for binary classification and 56% for ternary classification. Conclusion: Given the sample size and the variety of movement patterns presented in the demonstration, we conclude that a combination of biosignals and game parameters suffice to determine the occurrence of CS. However, substantial further research is required to improve binary classification accuracy to adequate values for real-life scenarios and to determine better approaches to classify its severity.

Immersive computer graphics systems strive to generate perceptually realistic user experiences. Current-generation virtual reality (VR) displays are successful in accurately rendering many perceptually important effects, including perspective, disparity, motion parallax, and other depth cues. In this article, we introduce ocular parallax rendering, a technology that accurately renders small amounts of gaze-contingent parallax capable of improving depth perception and realism in VR. Ocular parallax describes the small amounts of depth-dependent image shifts on the retina that are created as the eye rotates. The effect occurs because the centers of rotation and projection of the eye are not the same. We study the perceptual implications of ocular parallax rendering by designing and conducting a series of user experiments. Specifically, we estimate perceptual detection and discrimination thresholds for this effect and demonstrate that it is clearly visible in most VR applications. Additionally, we show that ocular parallax rendering provides an effective ordinal depth cue and it improves the impression of realistic depth in VR., Video: https://www.youtube.com/watch?v=FvBYYAObJNM&feature=youtu.be Project Page: http://www.computationalimaging.org/publications/gaze-contingent-ocular-parallax-rendering-for-virtual-reality/

Numerous users of Head Mounted Dis- plays develop symptoms similar to motion sickness. This phenomenon is known as cybersickness. The current standard method to evaluate it is the Simulator Sickness Questionnaire (SSQ). Additionally, detection by methods such as biosignals is possible, but it requires sophisti- cated equipment and expertise. In order to detect early cybersickness symptoms, the availability of real-time de- tection by using simple equipment, such as a 2-lead ECG, would be highly useful. This contribution aims to ana- lyze the feasibility of detecting cybersickness with a sim- ple 2 lead ECG. A total of 13 participants played the VR game QuakeVR wearing an Oculus Rift DK2 for 15 min- utes, during which a 2-lead ECG was recorded. Addi- tionally, pre- and post-SSQ questionnaires were given. Four of 13 participants had to end the experiment pre- maturely due to cybersickness. The difference in SSQ scores is statistically significant (p

The primary device for personal computing has consistently evolved over the years, from desktops to mobile devices, and now to the newly emerging trend of wearable computing. Wearable computing is expected to be integral to consumer electronics, with the primary mode of interaction for the user often being a near-eye display. To prepare for the shift to near-eye displays, several limitations of current-generation near-eye displays must be addressed, including the inability to provide fully natural focus cues for all users, which can lead to discomfort. A core issue causing these limitations is the optics of the systems themselves, with current displays simply being unable to reproduce changes in focus that natural vision entails. In addition, the form factor often makes it difficult for users with refractive errors to use their corrective eyewear. With two prototype near-eye displays employing computational optics, we demonstrate how these issues can be overcome using display modes that adapt to the user. These prototype systems make use of focus-tunable lenses, mechanically actuated displays, and gaze tracking technology to customize the experience to each specific user to correct common refractive errors, and provide natural focus cues by dynamically updating scene depth based on where a user looks in a scene. These and other advances in computational optics hint at a future in which computational optics enable some users to experience better vision in the virtual world than in the real one.

Objective The goal of this contribution is to gather and to critically analyze recent evidence regarding the potential of exergaming for Parkinson’s disease (PD) rehabilitation and to provide an up-to-date analysis of the current state of studies on exergame-based therapy in PD patients. Methods We performed our search based on the conclusions of a previous systematic review published in 2014. Inclusion criteria were articles published in the indexed databases Pubmed, Scopus, Sciencedirect, IEEE and Cochrane published since January 1, 2014. Exclusion criteria were papers with a target group other than PD patients exclusively, or contributions not based on exergames. Sixty-four publications out of 525 matches were selected. Results The analysis of the 64 selected publications confirmed the putative improvement in motor skills suggested by the results of the previous review. The reliability and safety of both Microsoft Kinect and Wii Balance Board in the proposed scenarios was further confirmed by several recent studies. Clinical trials present better (n = 5) or similar (n = 3) results than control groups (traditional rehabilitation or regular exercise) in motor (TUG, BBS) and cognitive (attention, alertness, working memory, executive function), thus emphasizing the potential of exergames in PD. Pilot studies (n = 11) stated the safety and feasibility of both Microsoft Kinect and Wii Balance Board, potentially in home scenarios as well. Technical papers (n = 30) stated the reliability of balance and gait data captured by both devices. Related meta-analyses and systematic reviews (n = 15) further support these statements, generally citing the need for adaptation to patient’s skills and new input devices and sensors as identified gaps. Conclusion Recent evidence indicates exergame-based therapy has been widely proven to be feasible, safe, and at least as effective as traditional PD rehabilitation. Further insight into new sensors, best practices and different cognitive stadiums of PD (such as PD with Mild Cognitive Impairment), as well as task specificity, are required. Also, studies linking game parameters and results with traditional assessment methods, such as UPDRS scores, are required. Outcomes for randomized controlled trials (RCTs) should be standardized, and follow-up studies are required, particularly for motor outcomes. Electronic supplementary material The online version of this article (10.1186/s12984-019-0492-1) contains supplementary material, which is available to authorized users.

Die Technische Universität Darmstadt wurde 1877 gegründet und ist Mitglied der TU9 der führenden technischen Universitäten in Deutschland. In der Informatik werden Lehrangebote für Serious Games und Game Technologie angeboten. Serious Games werden seit 2008 am Fachgebiet Multimedia Kommunikation erforscht und gelehrt.

The ubiquity of smartphones with integrated positioning systems, and multiple sensors for movement detection made it possible to develop context-sensitive applications for both productivity and entertainment. Location-based games like Ingress or Pokemon Go have demonstrated the public interest in this genre of mobile-only games – games that are exclusively available for mobile devices due to their sensor integration. For these games mobility is a key component, which defines and influences the game’s flow directly.

Programming game engines threatens to become an elitist activity with the industry split between the professional studios which are pushing for more direct but also more difficult to program hardware access and hobbyists using ready-made game-engines with little focus on understanding their inner workings. This paper presents an attempt to make game engine programming more accessible via a game programming framework which focuses explicitly on the programmers learning path in a similar manner to how video games are typically designed.

The goal of this work is to present and describe the development of a 6-Wii Balance Board array system for its use in exergaming scenarios. To avoid the main problem, which is connection stability and latency, we developed a board using a microcontroller from SILABS and a Bluetooth Stick was used to synchronize data acquisition and minimize data latency. Our data demonstrates that, under the described experimental conditions, the developed system is functional and is capable of delivering the data of 6 Wii Balance Boards in real time.

Pollen tubes (PTs) are characterized by having tip-focused cytosolic calcium ion (Ca

State-of-the-art near-eye displays often compromise on eye box size to maintain a wide field of view, necessitating a means for steering the eye box to maintain alignment with a moving eye. The design space of such pupil-steered systems is not well defined and the implications of imperfect steering on the perceived image are not well understood. To better characterize the pupil steering design space, we introduce a generalized taxonomy of pupil-steered architectures that considers both system and ocular factors that affect steering performance. We also develop an optical model of a generalized pupil-steered system with a wide-field schematic eye to simulate the retinal image. Using this framework, we systematically characterize retinal image quality for different combinations of design parameters. The results of these simulations provide an overview of the pupil steering design space and help determine relevant psychophysical experiments for further evaluation.

Although the impact of dementia on the health and well-being of those living with Alzheimer’s Disease and related Disorders (ADRD) and their care partners has been widely studied, less attention has been paid to how the disease impacts individuals within the context of their larger social networks. This symposium presents findings from a series of integrated studies aimed at strengthening measurement of health and well-being among older adults with living with dementia and well-being among members of their social networks. Findings will be presented from five studies: (1) a scoping review of social network measurement in older adults in chronic illness, including dementia, that emphasizes the use of technology in measuring older adults’ social networks; (2) a simulation study to evaluate the feasibility and reliability of sensor technology to measure social interaction among a person living with dementia and others in their immediate surroundings; (3) development of a web-based application that allows older adults to map and activate their social networks; (4) a qualitative analysis of interviews from persons living with dementia, their unpaid caregivers, and paid caregivers from an adult day health program concerning well-being focused outcomes; and (5) a mixed methods analysis of the feasibility of using both traditional and novel measures of health and well-being deployed among networks of people living with dementia. Emerging technologies for measuring social networks health and well-being hold promise for advancing the study of the relationship-based nature of care for people living with dementia.

© 2017 Copyright held by the owner/author(s). Although emerging virtual and augmented reality (VR/AR) systems can produce highly immersive experiences, they can also cause visual discomfort, eyestrain, and nausea. One of the sources of these symptoms is a mismatch between vergence and focus cues. In current VR/AR near-eye displays, a stereoscopic image pair drives the vergence state of the human visual system to arbitrary distances, but the accommodation, or focus, state of the eyes is optically driven towards a fixed distance. In this work, we introduce a new display technology, dubbed accommodation-invariant (AI) near-eye displays, to improve the consistency of depth cues in near-eye displays. Rather than producing correct focus cues, AI displays are optically engineered to produce visual stimuli that are invariant to the accommodation state of the eye. The accommodation system can then be driven by stereoscopic cues, and the mismatch between vergence and accommodation state of the eyes is significantly reduced. We validate the principle of operation of AI displays using a prototype display that allows for the accommodation state of users to be measured while they view visual stimuli using multiple different display modes.

Emerging virtual and augmented reality (VR/AR) systems can produce highly immersive experiences, but also induce visual discomfort, eyestrain, and nausea for some users. One of the sources of these symptoms is the lack of natural focus cues in all current VR/AR near-eye displays. These displays project stereoscopic image pairs, driving the vergence state of the eyes to arbitrary distances. However, the accommodation, or focus state of the eyes, is optically driven to a fixed distance. In this work, we empirically evalaute monovision: a simple, yet unconventional method for potentially driving the accommodation state of the eyes to two distances by allowing each eye to drive focus to a different distance.

Currently, numerous users who employ HMD devices such as the Oculus Rift develop symptoms similar to motion sickness. Recent literature defines this phenomenon as cybersickness, and one of its main causes as latency. This contribution aims to analyze the accuracy of different extrapolation and filtering techniques to accurately predict head movements, reducing the impact of latency. For this purpose, 10 participants played a VR game that required quick and subsequent head rotations, during which a total of 150.000 head positions were captured in the pitch and yaw rotation axes. These rotational movements were then extrapolated and filtered. Linear extrapolation seems to provide best results, with a prediction error of approximately 0.06 arc degrees. Filtering the extrapolated data further reduces the error to 0.04 arc degrees on average. In conclusion, until future VR systems can significantly reduce latency, extrapolating head movements seems to provide a low-cost solution with an acceptable prediction error, although extrapolating the roll axis movements remains to be challenging.

The number of impaired persons rises -- as a result of both regular degradation with age and psychological problems like burnout. Sheltered work organizations aim to reintegrate impaired persons into work environments and prepare them for the re-entry in the regular job market.Both for elderly and for impaired persons it is crucial to quickly assess the abilities, to identify limits and potentials and thus find work processes suitable for their skill profile.This work focuses on the analysis and comparison of software-tools that assess the abilities of persons with impairments. We describe two established generic tools (CANTAB, Cogstate), analyze a yet unknown specialized tool (Hamet) and present a new gamified tool (GATRAS).Finally, we present a study with 20 participants with impairments, comparing the tools against a ground truth baseline generated by a real-world assembly task.