A tutorial: Analyzing eye and head movements in virtual reality.

This tutorial provides instruction on how to use the eye tracking technology built into virtual reality (VR) headsets, emphasizing the analysis of head and eye movement data when an observer is situated in the center of an omnidirectional environment. We begin with a brief description of how VR eye movement research differs from previous forms of eye movement research, as well as identifying some outstanding gaps in the current literature. We then introduce the basic methodology used to collect VR eye movement data both in general and with regard to the specific data that we collected to illustrate different analytical approaches. We continue with an introduction of the foundational ideas regarding data analysis in VR, including frames of reference, how to map eye and head position, and event detection. In the next part, we introduce core head and eye data analyses focusing on determining where the head and eyes are directed. We then expand on what has been presented, introducing several novel spatial, spatio-temporal, and temporal head-eye data analysis techniques. We conclude with a reflection on what has been presented, and how the techniques introduced in this tutorial provide the scaffolding for extensions to more complex and dynamic VR environments.

Symptom burden and health-related quality of life in chronic kidney disease: A global systematic review and meta-analysis.

BACKGROUND: The importance of patient-reported outcome measurement in chronic kidney disease (CKD) populations has been established. However, there remains a lack of research that has synthesised data around CKD-specific symptom and health-related quality of life (HRQOL) burden globally, to inform focused measurement of the most relevant patient-important information in a way that minimises patient burden. The aim of this review was to synthesise symptom prevalence/severity and HRQOL data across the following CKD clinical groups globally: (1) stage 1-5 and not on renal replacement therapy (RRT), (2) receiving dialysis, or (3) in receipt of a kidney transplant. METHODS AND FINDINGS: MEDLINE, PsycINFO, and CINAHL were searched for English-language cross-sectional/longitudinal studies reporting prevalence and/or severity of symptoms and/or HRQOL in CKD, published between January 2000 and September 2021, including adult patients with CKD, and measuring symptom prevalence/severity and/or HRQOL using a patient-reported outcome measure (PROM). Random effects meta-analyses were used to pool data, stratified by CKD group: not on RRT, receiving dialysis, or in receipt of a kidney transplant. Methodological quality of included studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data, and an exploration of publication bias performed. The search identified 1,529 studies, of which 449, with 199,147 participants from 62 countries, were included in the analysis. Studies used 67 different symptom and HRQOL outcome measures, which provided data on 68 reported symptoms. Random effects meta-analyses highlighted the considerable symptom and HRQOL burden associated with CKD, with fatigue particularly prevalent, both in patients not on RRT (14 studies, 4,139 participants: 70%, 95% CI 60%-79%) and those receiving dialysis (21 studies, 2,943 participants: 70%, 95% CI 64%-76%). A number of symptoms were significantly (p < 0.05 after adjustment for multiple testing) less prevalent and/or less severe within the post-transplantation population, which may suggest attribution to CKD (fatigue, depression, itching, poor mobility, poor sleep, and dry mouth). Quality of life was commonly lower in patients on dialysis (36-Item Short Form Health Survey [SF-36] Mental Component Summary [MCS] 45.7 [95% CI 45.5-45.8]; SF-36 Physical Component Summary [PCS] 35.5 [95% CI 35.3-35.6]; 91 studies, 32,105 participants for MCS and PCS) than in other CKD populations (patients not on RRT: SF-36 MCS 66.6 [95% CI 66.5-66.6], p = 0.002; PCS 66.3 [95% CI 66.2-66.4], p = 0.002; 39 studies, 24,600 participants; transplant: MCS 50.0 [95% CI 49.9-50.1], p = 0.002; PCS 48.0 [95% CI 47.9-48.1], p = 0.002; 39 studies, 9,664 participants). Limitations of the analysis are the relatively few studies contributing to symptom severity estimates and inconsistent use of PROMs (different measures and time points) across the included literature, which hindered interpretation. CONCLUSIONS: The main findings highlight the considerable symptom and HRQOL burden associated with CKD. The synthesis provides a detailed overview of the symptom/HRQOL profile across clinical groups, which may support healthcare professionals when discussing, measuring, and managing the potential treatment burden associated with CKD. PROTOCOL REGISTRATION: PROSPERO CRD42020164737.

Ethical Considerations for the Inclusion of Patient-Reported Outcomes in Clinical Research: The PRO Ethics Guidelines.

Importance: Patient-reported outcomes (PROs) can inform health care decisions, regulatory decisions, and health care policy. They also can be used for audit/benchmarking and monitoring symptoms to provide timely care tailored to individual needs. However, several ethical issues have been raised in relation to PRO use. Objective: To develop international, consensus-based, PRO-specific ethical guidelines for clinical research. Evidence Review: The PRO ethics guidelines were developed following the Enhancing the Quality and Transparency of Health Research (EQUATOR) Network's guideline development framework. This included a systematic review of the ethical implications of PROs in clinical research. The databases MEDLINE (Ovid), Embase, AMED, and CINAHL were searched from inception until March 2020. The keywords patient reported outcome* and ethic* were used to search the databases. Two reviewers independently conducted title and abstract screening before full-text screening to determine eligibility. The review was supplemented by the SPIRIT-PRO Extension recommendations for trial protocol. Subsequently, a 2-round international Delphi process (n = 96 participants; May and August 2021) and a consensus meeting (n = 25 international participants; October 2021) were held. Prior to voting, consensus meeting participants were provided with a summary of the Delphi process results and information on whether the items aligned with existing ethical guidance. Findings: Twenty-three items were considered in the first round of the Delphi process: 6 relevant candidate items from the systematic review and 17 additional items drawn from the SPIRIT-PRO Extension. Ninety-six international participants voted on the relevant importance of each item for inclusion in ethical guidelines and 12 additional items were recommended for inclusion in round 2 of the Delphi (35 items in total). Fourteen items were recommended for inclusion at the consensus meeting (n = 25 participants). The final wording of the PRO ethical guidelines was agreed on by consensus meeting participants with input from 6 additional individuals. Included items focused on PRO-specific ethical issues relating to research rationale, objectives, eligibility requirements, PRO concepts and domains, PRO assessment schedules, sample size, PRO data monitoring, barriers to PRO completion, participant acceptability and burden, administration of PRO questionnaires for participants who are unable to self-report PRO data, input on PRO strategy by patient partners or members of the public, avoiding missing data, and dissemination plans. Conclusions and Relevance: The PRO ethics guidelines provide recommendations for ethical issues that should be addressed in PRO clinical research. Addressing ethical issues of PRO clinical research has the potential to ensure high-quality PRO data while minimizing participant risk, burden, and harm and protecting participant and researcher welfare.

Visual exploration of omnidirectional panoramic scenes.

How do we explore the visual environment around us, and how are head and eye movements coordinated during our exploration? To investigate this question, we had observers look at omnidirectional panoramic scenes, composed of both landscape and fractal images, using a virtual reality viewer while their eye and head movements were tracked. We analyzed the spatial distribution of eye fixations and the distribution of saccade directions and the spatial distribution of head positions and the distribution of head shifts, as well as the relation between eye and head movements. The results show that, for landscape scenes, eye and head behavior best fit the allocentric frame defined by the scene horizon, especially when head tilt (i.e., head rotation around the view axis) is considered. For fractal scenes, which have an isotropic texture, eye and head movements were executed primarily along the cardinal directions in world coordinates. The results also show that eye and head movements are closely linked in space and time in a complementary way, with stimulus-driven eye movements predominantly leading the head movements. Our study is the first to systematically examine eye and head movements in a panoramic virtual reality environment, and the results demonstrate that a virtual reality environment constitutes a powerful and informative research alternative to traditional methods for investigating looking behavior.

Turning the (virtual) world around: Patterns in saccade direction vary with picture orientation and shape in virtual reality.

Research investigating gaze in natural scenes has identified a number of spatial biases in where people look, but it is unclear whether these are partly due to constrained testing environments (e.g., a participant with their head restrained and looking at a landscape image framed within a computer monitor). We examined the extent to which image shape (square vs. circle), image rotation, and image content (landscapes vs. fractal images) influence eye and head movements in virtual reality (VR). Both the eyes and head were tracked while observers looked at natural scenes in a virtual environment. In line with previous work, we found a bias for saccade directions parallel to the image horizon, regardless of image shape or content. We found that, when allowed to do so, observers move both their eyes and head to explore images. Head rotation, however, was idiosyncratic; some observers rotated a lot, whereas others did not. Interestingly, the head rotated in line with the rotation of landscape but not fractal images. That head rotation and gaze direction respond differently to image content suggests that they may be under different control systems. We discuss our findings in relation to current theories on head and eye movement control and how insights from VR might inform more traditional eye-tracking studies.

The Use of Patient-Reported Outcomes in Patients Treated With Maintenance Hemodialysis: A Perspective.

There is increasing interest in the integration of patient-reported outcomes (PROs) into health care research and clinical practice for the benefit of patients with end-stage kidney disease receiving hemodialysis. In a research setting, PROs can be used as a patient-centered primary or secondary outcome in clinical studies. In routine care, PRO data may be used to support service delivery through benchmarking and audit or inform and enhance the care of the individual patient by improving patient-clinician communication. Despite evidence demonstrating the potential benefits of PROs and prioritization of these outcomes by patients, their use in kidney disease remains limited. Although there are significant methodological and operational challenges for the widespread integration of PROs, there is now consensus that this area should be at the forefront of clinical research and implementation science. We discuss the current use of PROs for patients with end-stage kidney disease receiving hemodialysis and identify a roadmap for increasing the evidence base and introducing PROs into mainstream clinical practice.

A patient-centred approach to measuring quality in kidney care: patient-reported outcome measures and patient-reported experience measures.

PURPOSE OF REVIEW: Chronic kidney disease (CKD) is associated with symptoms that can significantly reduce the health-related quality of life (HRQOL) of patients. Patient-reported outcome and experience measures (PROMs and PREMs) may assist with the evaluation of HRQOL and quality of care from the patient perspective. This review focuses on evidence from recent studies exploring the role of PROMs and PREMs in the measurement of quality in CKD care. RECENT FINDINGS: PROMs are increasingly used in CKD research as measures of clinical effectiveness, whereas the current use of PROMs in routine clinical settings and PREMs in all settings is more limited. Electronic PROMs may be sensitive enough to detect clinically relevant patient-reported outcomes changes. Patients on frequent shorter-hours daily haemodialysis may experience better HRQOL compared with those on conventional haemodialysis. PROM data may correlate significantly with clinical parameters. PREMs are being utilized by healthcare professionals to inform service improvements. SUMMARY: PROMs and PREMs may facilitate the measurement of quality in renal care and aid the tailoring of care to individual patients. PROMs may have a potential role as prognostic markers.

It depends on when you look at it: Salience influences eye movements in natural scene viewing and search early in time.

It is generally accepted that salience affects eye movements in simple artificially created search displays. However, no such consensus exists for eye movements in natural scenes, with several reports arguing that it is mostly high-level cognitive factors that control oculomotor behavior in natural scenes. Here, we manipulate the salience distribution across images by decreasing or increasing the contrast in a gradient across the image. We recorded eye movements in an encoding task (Experiment 1) and a visual search task (Experiment 2) and analyzed the relationship between the latency of fixations and subsequent saccade targeting throughout scene viewing. We find that short-latency first saccades are more likely to land on a region of the image with high salience than long-latency and subsequent saccades in both the encoding and visual search tasks. This implies that salience indeed influences oculomotor behavior in natural scenes, albeit on a different timescale than previously reported. We discuss our findings in relation to current theories of saccade control in natural scenes.

A comparison of scanpath comparison methods.

Interest has flourished in studying both the spatial and temporal aspects of eye movement behavior. This has sparked the development of a large number of new methods to compare scanpaths. In the present work, we present a detailed overview of common scanpath comparison measures. Each of these measures was developed to solve a specific problem, but quantifies different aspects of scanpath behavior and requires different data-processing techniques. To understand these differences, we applied each scanpath comparison method to data from an encoding and recognition experiment and compared their ability to reveal scanpath similarities within and between individuals looking at natural scenes. Results are discussed in terms of the unique aspects of scanpath behavior that the different methods quantify. We conclude by making recommendations for choosing an appropriate scanpath comparison measure.

Temporal dynamics of eye movements are related to differences in scene complexity and clutter.

Recent research has begun to explore not just the spatial distribution of eye fixations but also the temporal dynamics of how we look at the world. In this investigation, we assess how scene characteristics contribute to these fixation dynamics. In a free-viewing task, participants viewed three scene types: fractal, landscape, and social scenes. We used a relatively new method, recurrence quantification analysis (RQA), to quantify eye movement dynamics. RQA revealed that eye movement dynamics were dependent on the scene type viewed. To understand the underlying cause for these differences we applied a technique known as fractal analysis and discovered that complexity and clutter are two scene characteristics that affect fixation dynamics, but only in scenes with meaningful content. Critically, scene primitives-revealed by saliency analysis-had no impact on performance. In addition, we explored how RQA differs from the first half of the trial to the second half, as well as the potential to investigate the precision of fixation targeting by changing RQA radius values. Collectively, our results suggest that eye movement dynamics result from top-down viewing strategies that vary according to the meaning of a scene and its associated visual complexity and clutter.

Electronic Collection of Patient-Reported Outcomes to Improve Kidney Care: Benefits, Drawbacks, and Next Steps.

Kidney services worldwide are increasingly using digital health technologies to deliver care. This includes kidney electronic patient-reported outcome (ePRO) systems: ambulatory digital technologies that enable the capture of PRO data electronically from people with kidney disease remotely and in real time to be shared with their kidney care team. Current kidney ePRO systems commonly aim to support the monitoring and management of symptoms in patients with kidney disease. The majority have thus far only been implemented in research settings and are not yet routinely used in clinical practice, leaving their readiness for real-world implementation largely unknown. Compared with paper-based PRO collection, ePRO systems have certain advantages, which we categorize as efficiency benefits (e.g., lower administrative burden), direct patient care benefits (e.g., automated PRO-based patient education), and health system and research benefits (e.g., collecting ePRO data once for multiple purposes). At the same time, kidney ePRO systems come with drawbacks, such as their potential to exacerbate existing inequities in care and outcomes and to negatively affect staff burden and patients' experience of kidney care. Areas that hold promise for expediting the development and uptake of kidney ePRO systems at the local, organizational, and national level include harnessing national kidney registries as enabling infrastructures; using novel data-driven technologies (e.g., computerized adaptive test systems, configurable dashboards); applying implementation science and action research approaches to enhance translation of ePRO research findings into clinical practice; and engaging stakeholders, including patients and carers, health care professionals, policymakers, payers, ePRO experts, technology providers, and organizations that monitor and improve the quality of kidney services.

Patient-reported outcomes in integrated health and social care: A scoping review.

Background: Patient-reported outcomes (PROs) have potential to support integrated health and social care research and practice; however, evidence of their utilisation has not been synthesised. Objective: To identify PRO measures utilised in integrated care and adult social care research and practice and to chart the evidence of implementation factors influencing their uptake. Design: Scoping review of peer-reviewed literature. Data sources: Six databases (01 January 2010 to 19 May 2023). Study selection: Articles reporting PRO use with adults (18+ years) in integrated care or social care settings. Review methods: We screened articles against pre-specified eligibility criteria; 36 studies (23%) were extracted in duplicate for verification. We summarised the data using thematic analysis and descriptive statistics. Results: We identified 159 articles reporting on 216 PRO measures deployed in a social care or integrated care setting. Most articles used PRO measures as research tools. Eight (5.0%) articles used PRO measures as an intervention. Articles focused on community-dwelling participants (35.8%) or long-term care home residents (23.9%), with three articles (1.9%) focussing on integrated care settings. Stakeholders viewed PROs as feasible and acceptable, with benefits for care planning, health and wellbeing monitoring as well as quality assurance. Patient-reported outcome measure selection, administration and PRO data management were perceived implementation barriers. Conclusion: This scoping review showed increasing utilisation of PROs in adult social care and integrated care. Further research is needed to optimise PROs for care planning, design effective training resources and develop policies and service delivery models that prioritise secure, ethical management of PRO data.

Recommendations to address respondent burden associated with patient-reported outcome assessment.

Patient-reported outcomes (PROs) are increasingly used in healthcare research to provide evidence of the benefits and risks of interventions from the patient perspective and to inform regulatory decisions and health policy. The use of PROs in clinical practice can facilitate symptom monitoring, tailor care to individual needs, aid clinical decision-making and inform value-based healthcare initiatives. Despite their benefits, there are concerns that the potential burden on respondents may reduce their willingness to complete PROs, with potential impact on the completeness and quality of the data for decision-making. We therefore conducted an initial literature review to generate a list of candidate recommendations aimed at reducing respondent burden. This was followed by a two-stage Delphi survey by an international multi-stakeholder group. A consensus meeting was held to finalize the recommendations. The final consensus statement includes 19 recommendations to address PRO respondent burden in healthcare research and clinical practice. If implemented, these recommendations may reduce PRO respondent burden.

Recurrence quantification analysis of eye movements.

Recurrence quantification analysis (RQA) has been successfully used for describing dynamic systems that are too complex to be characterized adequately by standard methods in time series analysis. More recently, RQA has been used for analyzing the coordination of gaze patterns between cooperating individuals. Here, we extend RQA to the characterization of fixation sequences, and we show that the global and local temporal characteristics of fixation sequences can be captured by a small number of RQA measures that have a clear interpretation in this context. We applied RQA to the analysis of a study in which observers looked at different scenes under natural or gaze-contingent viewing conditions, and we found large differences in the RQA measures between the viewing conditions, indicating that RQA is a powerful new tool for the analysis of the temporal patterns of eye movement behavior.

Eye and head movements while encoding and recognizing panoramic scenes in virtual reality.

One approach to studying the recognition of scenes and objects relies on the comparison of eye movement patterns during encoding and recognition. Past studies typically analyzed the perception of flat stimuli of limited extent presented on a computer monitor that did not require head movements. In contrast, participants in the present study saw omnidirectional panoramic scenes through an immersive 3D virtual reality viewer, and they could move their head freely to inspect different parts of the visual scenes. This allowed us to examine how unconstrained observers use their head and eyes to encode and recognize visual scenes. By studying head and eye movement within a fully immersive environment, and applying cross-recurrence analysis, we found that eye movements are strongly influenced by the content of the visual environment, as are head movements-though to a much lesser degree. Moreover, we found that the head and eyes are linked, with the head supporting, and by and large mirroring the movements of the eyes, consistent with the notion that the head operates to support the acquisition of visual information by the eyes.

Eye Tracking in Virtual Reality.

This chapter explores the current state of the art in eye tracking within 3D virtual environments. It begins with the motivation for eye tracking in Virtual Reality (VR) in psychological research, followed by descriptions of the hardware and software used for presenting virtual environments as well as for tracking eye and head movements in VR. This is followed by a detailed description of an example project on eye and head tracking while observers look at 360° panoramic scenes. The example is illustrated with descriptions of the user interface and program excerpts to show the measurement of eye and head movements in VR. The chapter continues with fundamentals of data analysis, in particular methods for the determination of fixations and saccades when viewing spherical displays. We then extend these methodological considerations to determining the spatial and temporal coordination of the eyes and head in VR perception. The chapter concludes with a discussion of outstanding problems and future directions for conducting eye- and head-tracking research in VR. We hope that this chapter will serve as a primer for those intending to implement VR eye tracking in their own research.

Global use of electronic patient-reported outcome systems in nephrology: a mixed methods study.

OBJECTIVES: The use of electronic patient-reported outcome (ePRO) systems to support the management of patients with chronic kidney disease is increasing. This mixed-methods study aimed to comprehensively identify existing and developing ePRO systems, used in nephrology settings globally, ascertaining key characteristics and factors for successful implementation. STUDY DESIGN: ePRO systems and developers were identified through a scoping review of the literature and contact with field experts. Developers were invited to participate in a structured survey, to summarise key system characteristics including: (1) system objectives, (2) population, (3) PRO measures used, (4) level of automation, (5) reporting, (6) integration into workflow and (7) links to electronic health records/national registries. Subsequent semistructured interviews were conducted to explore responses. SETTING AND PARTICIPANTS: Eligible systems included those being developed or used in nephrology settings to assess ePROs and summarise results to care providers. System developers included those with a key responsibility for aspects of the design, development or implementation of an eligible system. ANALYTICAL APPROACH: Structured survey data were summarised using descriptive statistics. Interview transcripts were analysed using Codebook Thematic Analysis using domains from the Consolidated Framework for Implementation Research. RESULTS: Fifteen unique ePRO systems were identified across seven countries; 10 system developers completed the structured survey and 7 participated in semistructured interviews. Despite system heterogeneity, reported features required for effective implementation included early and sustained patient involvement, clinician champions and expanding existing electronic platforms to integrate ePROs. Systems demonstrated several common features, with the majority being implemented within research settings, thereby affecting system implementation readiness for real-world application. CONCLUSIONS: There has been considerable research investment in ePRO systems. The findings of this study outline key system features and factors to support the successful implementation of ePROs in routine kidney care.Cite Now.

Using XR (Extended Reality) for Behavioral, Clinical, and Learning Sciences Requires Updates in Infrastructure and Funding.

Extended reality (XR, including augmented and virtual reality) creates a powerful intersection between information technology and cognitive, clinical, and education sciences. XR technology has long captured the public imagination, and its development is the focus of major technology companies. This article demonstrates the potential of XR to (1) deliver behavioral insights, (2) transform clinical treatments, and (3) improve learning and education. However, without appropriate policy, funding, and infrastructural investment, many research institutions will struggle to keep pace with the advances and opportunities of XR. To realize the full potential of XR for basic and translational research, funding should incentivize (1) appropriate training, (2) open software solutions, and (3) collaborations between complementary academic and industry partners. Bolstering the XR research infrastructure with the right investments and incentives is vital for delivering on the potential for transformative discoveries, innovations, and applications.

Reading the room: Autistic traits, gaze behaviour, and the ability to infer social relationships.

Individuals high in autistic traits can have difficulty understanding verbal and non-verbal cues, and may display atypical gaze behaviour during social interactions. The aim of this study was to examine differences among neurotypical individuals with high and low levels of autistic traits with regard to their gaze behaviour and their ability to assess peers' social status accurately. Fifty-four university students who completed the 10-item Autism Quotient (AQ-10) were eye-tracked as they watched six 20-second video clips of people ("targets") involved in a group decision-making task. Simulating natural, everyday social interactions, the video clips included moments of debate, humour, interruptions, and cross talk. Results showed that high-scorers on the AQ-10 (i.e., those with more autistic traits) did not differ from the low-scorers in either gaze behaviour or assessing the targets' relative social status. The results based on this neurotypical group of participants suggest that the ability of individuals high in autistic traits to read social cues may be preserved in certain tasks crucial to navigating day-to-day social relationships. These findings are discussed in terms of their implications for theory of mind, weak central coherence, and social motivation theories of autism.