PotteryGo: A Virtual Pottery Making Training System.

Background Sustained attention is essential for effective learning, especially in virtual reality (VR) environments with a high degree of operational freedom. Electroencephalogram (EEG) feedback has proven effective in terms of monitoring and regulating students' attentional states. However, EEG feedback faces implementation challenges in VR environments. Auditory feedback may interfere with voice‐based learning content, while visual feedback can exacerbate the cognitive load in visually rich environments. Objective The aim was to explore methods that would help students maintain attention in the VR learning environment (including voice learning or voice guidance from virtual characters), thereby enhancing learning effectiveness. Method This study proposed and integrated a vibration‐based EEG feedback mechanism into a VR learning system. Grounded in the Cognitive Theory of Multimedia Learning, this approach leverages tactile prompts to avoid sensory conflict. A quasi‐experiment involving 64 university students was subsequently conducted in an English for Geography course. Of the participants, 32 were exposed to a VR environment incorporating the vibration‐based EEG feedback, while the other 32 used the same VR environment without the feedback. The data collection included students' attention levels, performance, and learning behaviours. Systematic records and interviews were used to retrace the students' states when the vibration feedback was triggered. Results and Conclusions Results showed that students in the VR learning system with vibration‐based EEG feedback exhibited higher attention levels, improved vocabulary memory and retention, and more structured behaviour patterns such as review and evaluation, planned learning and refocusing after EEG feedback. This study innovates EEG feedback in VR environments, providing a design reference to promote VR‐based learning. In addition, the results of identified scenarios and subjective reasons for inattention will help in the design of future language VR environments and learning activities.

The ergonomic design of control elements in real life has been researched in detail. Various studies exist on the optimal dimensioning, their haptic and acoustic feedback to achieve high control accuracy and user experience. But the development of products is increasingly done with virtual prototypes. Virtual reality (VR) allows these prototypes to be tested in a highly immersive environment. However, the findings from reality cannot be transferred to VR directly. For example, users in VR interact with the prototypes using controllers, which affects haptic feedback. This study investigates how rotary dials and joysticks must be designed and programmed in VR so that control tasks can be performed efficiently and generate a high user experience and perceived presence.In user tests, subjects (n = 25) evaluate the control of a joystick and a rotary dial in VR. In a virtual crane operator's cabin or at a virtual table, the subjects (f = 10, m = 15, age: 24 +- 3) perform four predefined tasks per control element. On two screens in VR, subjects see a vertical bar graph with a scale from 0 to 100 % controlled by the joystick and separately a numerical value between 0 and 100 % which is controlled by the rotary dial. The screens display the task to the subjects, e.g., "Set the value from 0 % to 42 %". According to the method “design of experiments”, 14 factors, such as vibration feedback, acoustic feedback, position of the subject or the sensitivity of the control element are systematically varied on two respectively three levels (e.g., diameter of actuator 40 mm, 80 mm or 110 mm). For each trial, the control accuracy and the time required to complete the task are determined. In addition, the perceived presence is assessed using the Slater-Usoh-Steed-Questionnaire and the user experience is surveyed using the User Experience Questionnaire. The effect of a change of level on the response parameters is investigated using multifactorial ANOVA (α = .05). Linear regression is used to calculate a mathematical relationship between factor and response parameter. These mathematical models are used to calculate which factor values can be used to achieve a high level of control accuracy with a low time requirement and a high level of user experience and perceived presence. The factors angular resolution, inclination, shape of the rotary dial and position of the subject have a highly significant effect (p ≤ .001) on the time required to complete the tasks with the rotary dial. On the control accuracy of the rotary dial, the angular resolution, the VR-controller and the interaction of angular resolution and diameter of the rotary dial have a significant effect. On the user experience, a total of six factors and two interactions have a significant effect. On the perceived presence of the subjects, the VR environment and the diameter of the rotary dial have a significant effect. The calculated optimized design is a rotary dial with vibration feedback, without acoustic feedback, with visualization of a rough knurling, an angular resolution of 10-12 degree/value, a 40 mm diameter and no inclination. Visualization of the hand should be avoided.Sensitivity, size, subject position, VR environment, and the interaction of subject position and VR environment have a significant effect on the time required to perform the control tasks with the joystick. Three factors and one interaction have a significant effect on the control accuracy of the joystick. The interaction of the factors vibration feedback and visualization of the hand has a significant effect on the perceived presence of the subjects. On user experience, nine factors and five interactions have a significant effect. The calculated optimized levels of factors for the joystick are vibration and acoustic feedback, no visual feedback, vertical handle with a height of 20-24 cm, a five-level angular resolution, a maximum deflection angle of +- 15°, a sensitivity of 8 %/sec and a visualization of the hand.The trials show a high degree of scatter. The residuals show outliers in the experiments. These deviations are mainly due to the individual previous experience of the test subjects in handling VR systems. Nevertheless, significant effects could be identified. A screening experimental design was used in this study. In a follow-up study, detailed investigations with a full factorial experimental design must be performed with the significant factors. The factors will be tested at multiple levels and with a significantly increased number of trials to further increase the accuracy of the mathematical models.

The effects of the presence of others during a rowing exercise in a virtual reality environment

In snowboard training, it is especially important to learn proper weight transfer and to perceive a gap between the perceived movement and the actual body movement. However, previous training systems don’t have sufficient function, and the effectiveness of each feedback on weight transfer, which includes not only the front and back but also left and right has not been reported. In this study, we propose and develop a real-time snowboard training system for a novice using visual and auditory feedback, and confirm its basic performance and effectiveness of each feedback. This system mainly consists of four components: (1) a center of pressure (COP) detection device, (2) a posture estimation device, (3) a visual feedback device, (4) an auditory feedback device. We experimented to confirm the feasibility to enhance motor learning by using the developed system and to evaluate the effectiveness of each feedback on weight transfer, which includes not only the front and back but also left and right. In conclusion, we developed a real-time snowboard training system for a novice using visual and auditory feedback and confirmed that our system could assist the proper weight transfer. Furthermore, in short-term learning, we confirmed that the effectiveness of each feedback, and visual feedback or visual and auditory feedback is the best way to enhance motor learning.

It has been suggested that the brain and in particular the cerebellum and motor cortex adapt to represent the environment during reaching movements under various visuomotor perturbations. It is well known that significant delay is present in neural conductance and processing; however, the possible representation of delay and adaptation to delayed visual feedback has been largely overlooked. Here we investigated the control of reaching movements in human subjects during an imposed visuomotor delay in a virtual reality environment. In the first experiment, when visual feedback was unexpectedly delayed, the hand movement overshot the end-point target, indicating a vision-based feedback control. Over the ensuing trials, movements gradually adapted and became accurate. When the delay was removed unexpectedly, movements systematically undershot the target, demonstrating that adaptation occurred within the vision-based feedback control mechanism. In a second experiment designed to broaden our understanding of the underlying mechanisms, we revealed similar after-effects for rhythmic reversal (out-and-back) movements. We present a computational model accounting for these results based on two adapted forward models, each tuned for a specific modality delay (proprioception or vision), and a third feedforward controller. The computational model, along with the experimental results, refutes delay representation in a pure forward vision-based predictor and suggests that adaptation occurred in the forward vision-based predictor, and concurrently in the state-based feedforward controller. Understanding how the brain compensates for conductance and processing delays is essential for understanding certain impairments concerning these neural delays as well as for the development of brain-machine interfaces.

Psychosis is characterized by a diminished ability of the brain to distinguish externally driven activity patterns from self-generated activity patterns. Antipsychotic drugs are a class of small molecules with relatively broad binding affinity for a variety of neuromodulator receptors that, in humans, can prevent or ameliorate psychosis. How these drugs influence the function of cortical circuits, and in particular their ability to distinguish between externally and self-generated activity patterns, is still largely unclear. To have experimental control over self-generated sensory feedback, we used a virtual reality environment in which the coupling between movement and visual feedback can be altered. We then used widefield calcium imaging to determine the cell type-specific functional effects of antipsychotic drugs in mouse dorsal cortex under different conditions of visuomotor coupling. By comparing cell type-specific activation patterns between locomotion onsets that were experimentally coupled to self-generated visual feedback and locomotion onsets that were not coupled, we show that deep cortical layers were differentially activated in these two conditions. We then show that the antipsychotic drug clozapine disrupted visuomotor integration at locomotion onsets also primarily in deep cortical layers. Given that one of the key components of visuomotor integration in cortex is long-range cortico-cortical connections, we tested whether the effect of clozapine was detectable in the correlation structure of activity patterns across dorsal cortex. We found that clozapine as well as two other antipsychotic drugs, aripiprazole and haloperidol, resulted in a strong reduction in correlations of layer 5 activity between cortical areas and impaired the spread of visuomotor prediction errors generated in visual cortex. Our results are consistent with the interpretation that a major functional effect of antipsychotic drugs is a selective alteration of long-range layer 5-mediated communication.

Ship painting personnel usually employ physical, hands-on training to enhance their proficiency and improve the quality of their painting. However, this method poses environmental pollution problems and has high costs. Therefore, this paper develops a ship artificial spraying simulation training system based on a Virtual Reality (VR) environment. Firstly, a artificial spraying model for a ship for personnel training is established by the relationship between the gun parameters, gun position, spraying direction, and coating thickness. A method for calculating the coating thickness and coating loss by using a frame cycle in a VR environment is proposed. And the artificial spraying model is verified from these two perspectives by a spraying test. Finally, based on the artificial spraying model, a ship spraying simulation training system is developed by combining C# and Unity3D, and a corresponding scoring mechanism is established to evaluate the spraying results. By recruiting personnel with different spraying experiences to wear VR helmets for spraying training trials, the results show that the method of using VR for spraying training can effectively improve the spraying level of operators with different spraying experiences.

BackgroundThe dorsal parietal visual system plays an important role in self-motion perception and spatial cognition. It also strongly responds to visual inputs from the lower visual field. Postural control is modified in a process called sensory reweighting based on the reliability of available sensory sources. The question of whether visual stimuli presented to either the lower or upper visual field affect postural control and sensory reweighting has not been resolved. Research questionDo visual stimuli presented to the lower and upper visual fields affect postural control and sensory reweighting? MethodsTwenty-nine healthy young adults participated in the study. Four conditions (full visual field, upper visual field, lower visual field, and no optic flow condition) were simulated in a VR environment using a head-mounted display. The optic flow stimuli used were swarms of small white spheres originating from the central point of the visual field, moving radially towards the periphery, and expanding across the scene. Participants were instructed to stand quietly for 50 s under each visual condition. Using force plate signals, we measured the center of pressure (COP) signal in the horizontal plane and calculated its 95 % ellipse area, root mean square (RMS) deviations, the mean velocity, and power spectral density (PSD). ResultsOptic flow in the full and lower visual fields produced significantly smaller 95 % ellipse area and RMS of COP in the anterior-posterior direction compared to optic flow in the upper visual field. Furthermore, the PSD of the lower frequency band (0–0.3 Hz) was decreased and that of higher frequency bands (0.3–1 Hz and 1–3 Hz) was increased for the lower compared to the upper visual field. SignificanceVisual feedback affects static postural control more when presented in the lower visual field compared to the upper visual field.

The combination of virtual reality (VR) and human-robot collaboration has revolutionized surgical procedures by providing immersive control, heightened accuracy, and improved coordination between the surgeon and the robot. This interaction allows for complex procedures that require increased flexibility and reduced invasiveness. Existing control algorithms are challenged with latency, limited multimodal data fusion, and an inability to adapt to newly updated surgical environments; thus, they are prone to reduced accuracy, suboptimal force control, or unsynchronized human and robot control. This article introduces a novel Adaptive Multimodal Reinforcement Learning (AMRL) framework that effectively incorporates visual, haptic, and auditory feedback for dynamic surgical control in a VR environment. The AMRL technique employs a continuous learning capability that allows the robot to learn from multimodal data and human intent, enabling responses utilizing real-time touch, sight, and sound. This enhanced adaptability facilitates coordination and accuracy of surgical procedures while reducing latency. The method will be applied and tested in Robotic-Assisted Laparoscopic Surgery (RALS), allowing the system to adapt in real-time to tissue changes and complex motion requirements. Experimental results demonstrate that the AMRL framework improves task completion accuracy, motion smoothness, and interaction efficiency compared to traditional multimodal control algorithms, creating a safer, more intuitive, and effective human-robot collaboration system for surgical practice.

Mandibular angle reduction is a popular and efficient procedure widely used to alter the facial contour. The primary surgical instruments, the reciprocating saw and the round burr, employed in the surgery have a common feature: operating at a high-speed. Generally, inexperienced surgeons need a long-time practice to learn how to minimize the risks caused by the uncontrolled contacts and cutting motions in manipulation of instruments with high-speed reciprocation or rotation. A virtual reality-based surgical simulator for the mandibular angle reduction was designed and implemented on a CUDA-based platform in this paper. High-fidelity visual and haptic feedbacks are provided to enhance the perception in a realistic virtual surgical environment. The impulse-based haptic models were employed to simulate the contact forces and torques on the instruments. It provides convincing haptic sensation for surgeons to control the instruments under different reciprocation or rotation velocities. The real-time methods for bone removal and reconstruction during surgical procedures have been proposed to support realistic visual feedbacks. The simulated contact forces were verified by comparing against the actual force data measured through the constructed mechanical platform. An empirical study based on the patient-specific data was conducted to evaluate the ability of the proposed system in training surgeons with various experiences. The results confirm the validity of our simulator.

This project sets up a design framework that promotes augmenting the human body's interactions exploring methods for merging and blending the users of physical and virtual environments, through the design of wearable devices that are embedded with sensors and actuators. This allows for haptic and visual feedback through the use of data that reflects changes in the surrounding physical environment, and visualized in the immersive Virtual Reality (VR) environment. We consider the Body Architectures project to serve as mechanisms for augmenting the body in relation to the virtual architecture. These wearable devices serve to bring a hyper-awareness to our senses, as closed-loop cybernetic systems that utilize 'digitized' biometric and environmental data through the use of 3D scanning technologies and cloud point models, virtual reality visualization, sensing technologies, and actuation. The design of Body Architectures relies on hybrid design, transdisciplinary collaborations, to explore new possibilities for wearable body architectures that evolve human-machine-environment interactions, and create hyper awareness of the temporal, atmospheric qualities that make up our experience of space, as 'sensorial envelopes' (Lally 2014).

The Simulation-Based Open Surgery Training System (SOSTS) is a virtual reality simulator designed to provide training on a simulated orthopedic bone pinning procedure. The present version of SOSTS offers five distinct combinations of multi-sensory feedback during training. The purpose of this study was to investigate the effects of visual and haptic feedback on participants' ability to place a pin through a fractured tibia on the simulator. Enhanced visual feedback resulted in a significant reduction of pin alignment error, although participants in these conditions took five times longer to achieve proficiency than those in the moderate visual feedback conditions. Any form of haptic feedback resulted in significantly greater pin placement error than no haptic feedback. The results provide partial support for the proximity compatibility principle for display design.

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Self-homodyne systems with polarization multiplexed carrier offer an LO-less coherent receiver with simplified signal processing requirement that can be a good candidate for high-speed short-reach data center interconnects. The practical implementation of these systems is limited by the requirement of polarization control at the receiver end for separating the carrier and the modulated signal. In this paper, effect of polarization impairments in polarization diversity based systems is studied and modeled. A novel and practical adaptive polarization control technique based on optical power feedback from one polarization is proposed for polarization multiplexed carrier based systems and verified through simulation results. The application of the proposed concept is experimentally demonstrated also for a QPSK system with polarization multiplexed carrier.

Virtual reality technologies enable the creation of environments for the assessment and training of motor deficits using enhanced feedback. This paper reports the development of a virtual reality environment applied toelectromyographic (EMG) biofeedbaclifor motor rehabilitation. It was modeled a 3D arm controlled by the EMG signals from brachial biceps muscle. The visual feedback was provided for user when the proposed goal was achieved. The system presented good performance by the evaluation of healthy subjects and physiotherapists. The project has excellent perspective to be applied to motor recovery for patients with different impairments.