Presence in virtual environments: Objective metrics vs. subjective metrics — A pilot study

Home healthcare devices have gained attention recently as more and more care is being delivered in the patients’ home rather than in a hospital setting. This trend is accelerating as healthcare systems work to restrain costs and provide patients with the tangible benefits of receiving care in their own home. Because the user population of these devices is moving away from trained professionals, the usability of home healthcare devices takes on greater importance. Poor usability of these devices could result in negative consequences, ranging from incorrect diagnoses to patient injury or death. In this study, the usability of four common home healthcare devices (a manual blood pressure monitor, a temporal artery thermometer, a pulse oximeter, and a spirometer) was evaluated by 74 participants. The objective metrics of effectiveness (success), efficiency (time on task) and the subjective metric of satisfaction were collected for each device, and correlated with the users’ subjective assessment of the usability of each device, as measured with the System Usability Scale (SUS). Results show that there is a positive correlation between effectiveness and SUS scores, no correlation between efficiency and SUS, and a positive correlation between satisfaction and SUS.

User attributes in processing 3D VR-enabled showroom: Gender, visual cognitive styles, and the sense of presence

The main goal of hiding data is to conceal the very existence of the hidden information, therefore there is a significant demand for steganographic approaches that can ensure imperceptibility of such infromation. However, there is a limited corresponding evaluation parameters available. Most of the studies use the Peak Signal to Noise Ratio (PSNR) as a metric for imperceptibility evaluation, although it could provide less accurate results than the Human Visual System (HVS) evaluation. This paper provides a review of the existent evaluation metrics that are used to assess the quality of steganography. The examination of the correlation between the existing objective and subjective metrics is also conducted. Pixel differences metrics have a poor correlation with the subjective metrics, hence the HSV based metrics have better correlation than pixel metrics.

Virtual environments are being designed and implemented to accommodate diverse experiences of real space. Form and content are two basic concepts that have a significant impact on the sense of presence in virtual environments. Architectural design has a particular meaningful role in designing and creating form in which content takes place. Recent explorations found that these concepts may open a new understanding of innovative design paradigms that can induce the sense of presence. This chapter discusses current research in the design of presence in virtual environments. It presents and investigates the impact of two paradigms that integrate the components of form and content: the first is termed as “task-based design” and the second is termed as “scenario-based design”.

Evaluating autostereoscopic 3D baseball games using signal detection theory and receiver operating characteristic space

Flashbulb memories represent a unique phenomenon linking research on cognition with research on emotion, yet most studies on this phenomenon have characterized collective events that are negative and unexpected in nature. In contrast, the 2016 American election of Donald Trump was a public, culturally shared event, eliciting extreme emotional responses that were positive for some individuals but negative for others, as well as varying levels of surprise. We longitudinally evaluated autobiographical memories for Election Night 2016 in a large online sample of Clinton supporters, Trump supporters, and third-party/nonvoters over a 12-month period, in terms of both objective memory metrics (information quantity and memory consistency) and subjective memory metrics (including memory confidence, metacognition, and sensory experience). Emotional responses to the election outcome varied widely, with Clinton supporters reporting highly negative responses, Trump supporters reporting highly positive responses, and third-party/nonvoters reporting mildly negative responses. Emotional intensity was enhanced in surprised versus nonsurprised individuals. Relative to third-party/nonvoters, Clinton and Trump supporters reported greater memory vividness, event importance, and sensory experience. Additionally, limited valence effects on subjective memory were observed (including higher memory confidence in Trump supporters and higher memory rehearsal in Clinton supporters). These differences in subjective experience were observed despite similar levels of information quantity and consistency as a function of valence. This characterization of memories for surprising positive events suggests they share many of the paradoxical qualities of memories for negative events often discussed as "flashbulb memories" but also points to potential differences in memory phenomenology for personal versus collectively experienced events. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

With the increasing complexity of system-on-chip (SoC) design, intellectual property (IP)-based design flow is becoming an inevitable trend to achieve high performance and short time-to-market. However the transfer of IP core remains a complex and time-consuming process. Different IP vendors usually use different design rules and tool flows, which make it difficult for IP integrators to select suitable IP cores and integrate them rapidly. In this paper, a common platform for IP qualification (CPIPQ) is presented to provide and establish a set of common standards to qualify Soft/Hard IP. There are two kinds of qualification methods: subjective quality metric and objective quality metric. We use IEEE QIP Metric to evaluate the subjective quality metrics of IP cores. Objective metrics are measured automatically by using commercial EDA tools, as well as tools that developed by ASTRI IC Design Group.

Investigation of visual and game-playing performance under different genders, display and operation interfaces

The measurement and evaluation of the QoE (Quality of Experience) have become one of the main focuses in the telecommunications to provide services with the expected quality for their users. However, factors like the network parameters and codification can affect the quality of video, limiting the correlation between the objective and subjective metrics. The above increases the complexity to evaluate the real quality of video perceived by users. In this paper, a model based on artificial neural networks such as BPNNs (Backpropagation Neural Networks) and the RNNs (Random Neural Networks) is applied to evaluate the subjective quality metrics MOS (Mean Opinion Score) and the PSNR (Peak Signal Noise Ratio), SSIM (Structural Similarity Index Metric), VQM (Video Quality Metric), and QIBF (Quality Index Based Frame). The proposed model allows establishing the QoS (Quality of Service) based in the strategyDiffserv. The metrics were analyzed through Pearson’s and Spearman’s correlation coefficients, RMSE (Root Mean Square Error), and outliers rate. Correlation values greater than 90% were obtained for all the evaluated metrics.

Studying fatigue is challenging because it is influenced by physiological, psychological, and sociological states. Fatigue can be assessed objectively or subjectively, but the literature has difficulty understanding how an analytical test relates to a response via a questionnaire. Thus, the purpose of this study was to evaluate the relationships between objective fatigue variables (Squat Jump (SJ) and Countermovement Jump (CMJ)) measured on day-2 to the game and subjective fatigue (Rating Perceived Exertion (RPE) measured on day-3 to the game and Hooper Index (HI) measured on day-2). The sample comprised 32 professional football players from the First Portuguese League aged 25.86 ± 3.15 years. The Spearman correlations and regression analyses were used to study the relationships between the variables. The results showed statistically significant (p < 0.05) but small correlations (0.113–0.172) between several objective metrics and the subjective metrics evaluated. In addition, we found two weak models with statistical significance (p < 0.05) between the dependent objective variables (contact time, height, and elasticity index) and the HI ( = 3.7%) and RPE ( = 1.6%). Also, nine statistically significant (p < 0.05) but weak models were observed between the subjective dependent variables (HI and RPE) and contact time ( = 1.8–2.7%), flight time ( = 1.1–1.9%), height ( = 1.2–2.3%), power ( = 1.4%), pace ( = 1.2–2.1%), and elasticity index ( = 1.6%). In conclusion, objective and subjective fatigue-monitoring tests in professional soccer do not measure identical but rather complementary aspects of fatigue, and therefore, both need to be considered to gain a holistic perspective.

A series of 3 studies was conducted to test free-modulus magnitude estimation as a measure of perceived presence in virtual environments (VEs) and to model the first- and second-order effects of 11 VE system parameters on perceived presence across 5 subtasks. Sequential experimentation techniques were used to build 4 empirical models using polynomial regression. An integrated empirical model of data combined across 2 experiments demonstrated that all significant factors had a positive effect on perceived presence. Three of these parameters--field of view, sound, and head tracking--had almost 3 times as much influence on presence than the other 4 significant parameters, which were visual display resolution, texture mapping, stereopsis, and scene update rate. Sequential experimentation was an efficient tool for building empirical models of perceived presence, but the subjective nature of this phenomenon and individual differences made data bridging across sequential studies problematic. It was concluded that magnitude estimation is a useful measure of perceived presence, and the resulting polynomial regression models can be used to facilitate VE system design decisions. This research has broad application in the selection and design of VE system components and overall design of VE systems.

Haptic interaction in slow virtual environments (VEs) can become unstable due to the phase lag introduced in the control loop by the slow update rate of the VE. Increasing the physical damping and/or limiting the contact stiffness rendered to users can mitigate the destabilizing effect of the low VE update rate. However, large physical damping and compliant virtual contacts decrease the sense of presence in VEs, especially during interaction with rigid virtual objects. To increase the maximum virtual contact stiffness that can be rendered to users without increasing the interface damping, this paper proposes a control strategy based on multirate wave communications between a haptic interface and a VE updated at a slow and fixed rate. The multirate wave communications are shown to be guaranteed passive only if the decrease of the wave sampling rate at the connection between the haptic interface and the VE does not cause aliasing. Therefore, an antialiasing low-pass filter is placed before the wave rate drop in the communications. The passivity condition is verified analytically and numerically for multirate haptic interaction in VEs with various contact stiffnesses and update rates. The transparency of haptic interaction in slow VEs to which users connect via passive multirate wave communications is investigated analytically in the frequency domain. Experiments validate that passive multirate wave communications can render stiffer contact in slow VEs than conventional direct coupling, and illustrate the destabilizing effect of the aliasing caused by the sampling rate drop in the communications.

Driving fatigue analysis using multimodal physiological signals has become a growing focus in human factor engineering research. We introduce the Multimodal Phenotyping Dataset of Driving Fatigue (MPD-DF), a public resource comprising data from 50 participants (35 females and 15 males) during a standardized 2-hour simulated driving task. The dataset includes multidimensional subjective and objective metrics for fatigue assessment, comprising multimodal physiological recordings (32-channel electroencephalogram, single-lead electrocardiogram, dual-channel electrooculogram, and thoracic respiratory effort signals), fatigue-associated questionnaire results, and expert physician annotations of fatigue levels. To the best of our knowledge, it contains the largest number of signal modalities and provides the first physician-annotated, EEG-based fatigue labels among existing public datasets. The dataset validity was evaluated across multiple dimensions, including fatigue induction efficacy, statistical analysis of questionnaire outcomes, physiological signal quality, and correlations between physiological signals and annotated fatigue levels. This extensively characterized and validated dataset provides a benchmark resource for developing fatigue detection algorithms, facilitating cross-dataset validation, and advancing mechanistic studies of driving fatigue to enhance transportation safety.

Recently, we have seen an emergence of affordable Head Mounted Displays (HMD) such as the Oculus Rift, HTC Vive, and the PS4 Project Morpheus which allow users to experience 3D virtual reality (VR). These types of hardware aim to facilitate new and novel experiences for users above and beyond what is possible with traditional audiovisual displays. However, a very limited number of studies exist in the literature to determine the influence of these technologies on user Quality of Experience (QoE). In order to evaluate QoE as users consume VR content, this paper proposes the use of affordable consumer electronics to capture objective physiological metrics: Heart Rate (HR) and ElectroDermal Activity (EDA). Our findings indicate different HR and EDA dependent on VR and non-VR environments. Additionally, we examine the relationship between these objective metrics and user QoE captured via a post-test questionnaire. To the best of the authors knowledge, this is the first work which demonstrates a tangible relationship between the EDA/HR combination and user QoE of immersive VR environments.

Surgical simulation practices have witnessed a rapid expansion as an invaluable approach to resident training in recent years. One emerging way of implementing simulation is the adoption of extended reality (XR) technologies, which enable trainees to hone their skills by allowing interaction with virtual 3D objects placed in either real-world imagery or virtual environments. The goal of the present systematic review is to survey and broach the topic of XR in neurosurgery, with a focus on education. Five databases were investigated, leading to the inclusion of 31 studies after a thorough reviewing process. Focusing on user performance (UP) and user experience (UX), the body of evidence provided by these 31 studies showed that this technology has, in fact, the potential of enhancing neurosurgical education through the use of a wide array of both objective and subjective metrics. Recent research on the topic has so far produced solid results, particularly showing improvements in young residents, compared to other groups and over time. In conclusion, this review not only aids to a better understanding of the use of XR in neurosurgical education, but also highlights the areas where further research is entailed while also providing valuable insight into future applications.