Swimming with a head-mounted display: dual-task costs.

Head-up displays (HUDs) have the potential to change work in operation environments by providing hands-free information to wearers. However, these benefits may be accompanied by trade-offs, primarily by increasing cognitive load due to dividing attention. Previous studies have attempted to understand the trade-offs of HUD usage; however, all of which were focused on land-based tasks. A gap in understanding exists when examining HUD use in aquatic environments as immersion introduces unique environmental and physiological factors that could affect multitasking. In this study, we investigated multitasking performance associated with swimming with a HUD. Eighteen participants completed three tasks: swimming only, a HUD-administered word recall task, and a dual-task combining both tasks. Results revealed significant dual-task interference in both tasks, though possibly less pronounced than in land-based tasks. These findings enhance not only help characterise dual-task performance, but also offer valuable insights for HUD design for aquatic settings.

HUDs have become an increasingly popular tool to present information to users in complex working environments. However, past research examining HUD task performance has been restricted to land-based contexts. The current study examines HUD use while swimming and provides characterisation of multitasking performance within aquatic environments.

Emotion Recognition in a Health Continuum: Comparison of Healthy Adults of Advancing Age, Community Dwelling Adults Bearing Vascular Risk Factors and People Diagnosed with Mild Cognitive Impairment.

The identification of basic emotions plays an important role in social relationships and behaviors linked to survival. In neurodegenerative conditions such as Alzheimer's disease (AD), the ability to recognize emotions may already be impaired at early stages of the disease, such as the stage of Mild Cognitive Impairment (MCI). However, as regards vascular pathologies related to cognitive impairment, very little is known about emotion recognition in people bearing vascular risk factors (VRF). Therefore, the aim of the present study was to examine emotion recognition ability in the health continuum "healthy advancing age-advancing age with VRF-MCI". The sample consisted of 106 adults divided in three diagnostic groups; 43 adults with MCI, 41 adults bearing one or more VRF, and 22 healthy controls of advancing age (HC). Since HC were more educated and younger than the other two groups, the age-group and level of educational were taken into account in the statistical analyses. A dynamic visual test was administered to examine recognition of basic emotions and emotionally neutral conditions. The results showed only a significant diagnostic group x educational level interaction as regards total emotion recognition ability, F (4, 28.910) = 4.117 p = 0.004 η2 = 0.166. High educational level seems to contribute to a high-level-emotion-recognition-performance both in healthy adults of advancing age and in adults bearing vascular risk factors. Medium educational level appears to play the same role only in healthy adults. Neither educational level can help MCI people to enhance their significantly lower emotion recognition ability.

Assessing Consistency in Single-Case Data Features Using Modified Brinley Plots.

The current text deals with the assessment of consistency of data features from experimentally similar phases and consistency of effects in single-case experimental designs. Although consistency is frequently mentioned as a critical feature, few quantifications have been proposed so far: namely, under the acronyms CONDAP (consistency of data patterns in similar phases) and CONEFF (consistency of effects). Whereas CONDAP allows assessing the consistency of data patterns, the proposals made here focus on the consistency of data features such as level, trend, and variability, as represented by summary measures (mean, ordinary least squares slope, and standard deviation, respectively). The assessment of consistency of effect is also made in terms of these three data features, while also including the study of the consistency of an immediate effect (if expected). The summary measures are represented as points on a modified Brinley plot and their similarity is assessed via quantifications of distance. Both absolute and relative measures of consistency are proposed: the former expressed in the same measurement units as the outcome variable and the latter as a percentage. Illustrations with real data sets (multiple baseline, ABAB, and alternating treatments designs) show the wide applicability of the proposals. We developed a user-friendly website to offer both the graphical representations and the quantifications.

Communicating Uncertainties About the Effects of Medical Interventions Using Different Display Formats.

Communicating uncertainties in scientific evidence is important to accurately reflect scientific knowledge , increase public understanding of uncertainty, and to signal transparency and honesty in reporting. While techniques have been developed to facilitate the communication of uncertainty, many have not been empirically tested, compared for communicating different types of uncertainty, or their effects on different cognitive, trust, and behavioral outcomes have not been evaluated. The present study examined how a point estimate, imprecise estimate, conflicting estimates, or a statement about the lack of evidence about treatment effects, influenced participant's responses to communications about medical evidence. For each type of uncertainty, we adapted three display formats to communicate the information: tables, bar graphs, and icon arrays. We compared participant's best estimates of treatment effects, as well as effects on recall, subjective evaluations (understandability and usefuleness), certainty perceptions, perceptions of trustworthiness of the information, and behavioral intentions. We did not find any detrimental effects from communicating imprecision or conflicting estimates relative to a point estimate across any outcome. Furthermore, there were more favorable responses to communicating imprecision or conflicting estimates relative to lack of evidence, where participants estimated the treatment would improve outcomes by 30-50% relative to a placebo. There were no differences across display formats, suggesting that, if well-designed, it may not matter which format is used. Future research on specific display formats or uncertainty types and with larger sample sizes would be needed to detect small effects. Implications for the communication of uncertainty are discussed.

Shared Gaze Fails to Improve Team Visual Monitoring.

OBJECTIVE: The aim was to test the value of shared gaze as a way to improve team performance in a visual monitoring task. BACKGROUND: Teams outperform individuals in monitoring tasks, but fall short of achievable levels. Shared-gaze displays offer a potential method of improving team efficiency. Within a shared-gaze arrangement, operators collaborate on a visual task, and each team member's display includes a cursor to represent the other teammates' point of regard. Past work has suggested that shared gaze allows operators to better communicate and coordinate their attentional scanning in a visual search task. The current experiments sought to replicate and extend earlier findings of inefficient team performance in a visual monitoring task, and asked whether shared gaze would improve team efficiency. METHOD: Participants performed a visual monitoring task framed as a sonar operation. Displays were matrices of luminance patches varying in intensity. The participants' task was to monitor for occasional critical signals, patches of high luminance. In Experiment 1, pairs of participants performed the task independently, or working as teams. In Experiment 2, teams of two participants performed the task with or without shared-gaze displays. RESULTS: In Experiment 1, teams detected more critical signals than individuals, but were statistically inefficient; detection rates were lower than predicted by a control model that assumed pairs of operators searching in isolation. In Experiment 2, shared gaze failed to increase target detection rates. CONCLUSION AND APPLICATION: Operators collaborate inefficiently in visual monitoring tasks, and shared gaze does not improve their performance.

Communication of Hazards in Mixed-Reality Telerobotic Systems: The Usage of Naturalistic Avoidance Cues in Driving Tasks.

OBJECTIVE: This study investigates the effect of naturalistic visual cues on human avoidance behavior for a potential use in telerobotic user interfaces incorporating mixed-reality environments (e.g., augmented reality). BACKGROUND: Telerobotic systems used in hazardous environments require interfaces that draw operators' attention to potential dangers. Existing means of hazard notification can often distract or induce stress in operators. In the design and implementation of such interfaces, visual semiotics plays a critical role in creating more effective interfaces. Naturalistic visual cues such as Aposematism or Kindchenschema have proven effective to communicate danger or caution in nature, but the application of these cues in visual systems have yet to be thoroughly investigated. METHOD: A study was conducted where 40 volunteering participants were asked to control a remote vehicle in a simulated environment. The environment contained a set of neutral and visually augmented obstacles that were designed to provoke avoidance behavior. RESULTS: The use of visual cues triggered greater avoidance behaviors in participants compared to neutral obstacles. The distance of avoidance was correlated with the type of cue present, with obstacles augmented by Aposematism (Cue A) having a greater participant-obstacle distance than Kindchenschema (Cue K). CONCLUSIONS: This study shows the potential for the incorporation of naturalistic visual cues as a means to designate warning or caution in telerobotic environments. APPLICATIONS: The findings can offer practical guidelines for the design of visual cues in telerobotic interfaces. The further incorporation of such cues may reduce operator stress and the amount of human errors in telerobotic operations.

Reconciling print-size and display-size constraints on reading.

Two fundamental constraints limit the number of characters in text that can be displayed at one time-print size and display size. These dual constraints conflict in two important situations-when people with normal vision read text on small digital displays, and when people with low vision read magnified text. Here, we describe a unified framework for evaluating the joint impact of these constraints on reading performance. We measured reading speed as a function of print size for three digital formats (laptop, tablet, and cellphone) for 30 normally sighted and 10 low-vision participants. Our results showed that a minimum number of characters per line is required to achieve a criterion of 80% of maximum reading speed: 13 characters for normally sighted and eight characters for low-vision readers. This critical number of characters is nearly constant across font and display format. Possible reasons for this required number of characters are discussed. Combining these character count constraints with the requirements for adequate print size reveals that an individual's use of a small digital display or the need for magnified print can shrink or entirely eliminate the range of print size necessary for achieving maximum reading speed.

Lighting up the NMJ: developing an LED-based model of the neuromuscular junction for the undergraduate classroom.

Many complex physiological processes can be introduced and explored using the framework of the neuromuscular junction (NMJ), including neurotransmitter release, membrane depolarization, and ion channel activity. While traditionally used instructional tools such as static complex drawings are useful, these images can be incomplete physiological representations due to the lack of physically moving parts. As a result, they often misrepresent the complexity of physiological phenomena to students. We describe an effort to create a more accurate, dynamic representation of the NMJ to enhance instruction in an undergraduate anatomy and physiology course. We sought to create a unique and memorable moving diagram that combines elements of static images with moving parts. To evaluate the impact of the dynamic model, students were asked about their understanding of the NMJ before and after exposure to the model. In addition, students were asked for attitudinal responses to the model and their preferred method of instruction. Analysis of student responses indicated that students enjoyed the model, although they also had concerns about the speed of the simulated ion movement being too fast. The model has also served as an informal science education art installation in presentations for prospective students, stakeholders in the broader community, including local and statewide politicians, the University president and board of trustees, donors, and other regional economic and educational leaders.

The pitfalls of the traditional office ergonomics model in the current mobile work environment: Is visual ergonomics health literacy the remedy?

Mobile technology has revolutionised how we work. It is now relatively easy to work anywhere and anytime, but this has placed the onus is on mobile (or flexible) workers to set up their own work environment for comfort and ease of use. Vision is an important driver of posture, and hence visual ergonomics principles are integral for setting up digital devices. If mobile workers do not have visual ergonomics knowledge, or are unable to apply visual ergonomics knowledge to appropriately set up their work environment, then they are at risk of developing visual-related occupational health issues due to exposure to adverse physical work environments. To address this potential health care issue, we propose the introduction of Visual Ergonomics Health Literacy. This would provide mobile workers (including school children) with the knowledge and skills to set up their work environment for comfort and ease of use, wherever they work. It is important to address this issue now before we have a widespread epidemic of discomfort and injury from not applying sound visual ergonomics principles to work environments.

Social group signatures in hummingbird displays provide evidence of co-occurrence of vocal and visual learning.

Vocal learning, in which animals modify their vocalizations based on social experience, has evolved in several lineages of mammals and birds, including humans. Despite much attention, the question of how this key cognitive trait has evolved remains unanswered. The motor theory for the origin of vocal learning posits that neural centres specialized for vocal learning arose from adjacent areas in the brain devoted to general motor learning. One prediction of this hypothesis is that visual displays that rely on complex motor patterns may also be learned in taxa with vocal learning. While learning of both spoken and gestural languages is well documented in humans, the occurrence of learned visual displays has rarely been examined in non-human animals. We tested for geographical variation consistent with learning of visual displays in long-billed hermits ( Phaethornis longirostris), a lek-mating hummingbird that, like humans, has both learned vocalizations and elaborate visual displays. We found lek-level signatures in both vocal parameters and visual display features, including display element proportions, sequence syntax and fine-scale parameters of elements. This variation was not associated with genetic differentiation between leks. In the absence of genetic differences, geographical variation in vocal signals at small scales is most parsimoniously attributed to learning, suggesting a significant role of social learning in visual display ontogeny. The co-occurrence of learning in vocal and visual displays would be consistent with a parallel evolution of these two signal modalities in this species.

Behavioral Changes to Repeated Takeovers in Highly Automated Driving: Effects of the Takeover-Request Design and the Nondriving-Related Task Modality.

OBJECTIVE: We investigated drivers' behavior and subjective experience when repeatedly taking over their vehicles' control depending on the design of the takeover request (TOR) and the modality of the nondriving-related task (NDRT). BACKGROUND: Previous research has shown that taking over vehicle control after highly automated driving provides several problems for drivers. There is evidence that the TOR design and the NDRT modality may influence takeover behavior and that driver behavior changes with more experience. METHOD: Forty participants were requested to resume control of their simulated vehicle six times. The TOR design (auditory or visual-auditory) and the NDRT modality (auditory or visual) were varied. Drivers' takeover behavior, gaze patterns, and subjective workload were recorded and analyzed. RESULTS: Results suggest that drivers change their behavior to the repeated experience of takeover situations. An auditory TOR leads to safer takeover behavior than a visual-auditory TOR. And with an auditory TOR, the takeover behavior improves with experience. Engaging in the visually demanding NDRT leads to fewer gazes on the road than the auditory NDRT. Participants' fixation duration on the road decreased over the three takeovers with the visually demanding NDRT. CONCLUSIONS: The results imply that (a) drivers change their behavior to repeated takeovers, (b) auditory TOR designs might be preferable over visual-auditory TOR designs, and (c) auditory demanding NDRTs allow drivers to focus more on the driving scene. APPLICATION: The results of the present study can be used to design TORs and determine allowed NDRTs in highly automated driving.

Effect of Visualization Training on Uncertain Spatial Trajectory Predictions.

OBJECTIVE: The goal of this study was to explore the ways in which visualizations influence the prediction of uncertain spatial trajectories (e.g., the unknown path of a downed aircraft or future path of a hurricane) and participant overconfidence in such prediction. BACKGROUND: Previous research indicated that spatial predictions of uncertain trajectories are challenging and are often associated with overconfidence. Introducing a visualization aid during training may improve the understanding of uncertainty and reduce overconfidence. METHOD: Two experiments asked participants to predict the location of various trajectories at a future time. Mean and variance estimates were compared for participants who were provided with a visualization and those who were not. RESULTS: In Experiment 1, participants exhibited less error in mean estimations when a linear visualization was present but performed worse than controls once the visualization was removed. Similar results were shown in Experiment 2, with a nonlinear visualization. However, in both experiments, participants who were provided with a visualization did not retain any advantage in their variance estimations once the visualization was removed. CONCLUSIONS: Visualizations may support spatial predictions under uncertainty, but they are associated with benefits and costs for the underlying knowledge being developed. APPLICATION: Visualizations have the potential to influence how people make spatial predictions in the presence of uncertainty. Properly designed and implemented visualizations may help mitigate the cognitive biases related to such predictions.

Tracking and discrete dual task performance for different visual spatial stimulus-response mappings with focal and ambient vision.

The effect of spatial compatibility for various display-control configurations on human performance was studied with a dual-task paradigm using a tracking task and a discrete response task. Degradation of performance on both tasks within the visual modality was observed and was considered to be most likely due to resource competition resulting from simultaneous task operation. It was found that the more complicated the mapping for the discrete spatial compatibility response task, the more severe the interference with the tracking task. Although performance on both the tracking and spatial response tasks was impaired, the magnitude of impairment was not as great as expected, implying that focal and ambient vision required for the tracking task and spatial task, respectively, might be deployed, at least partly, from separate resources. Participants here seemed to successfully use focal vision for tracking and ambient vision for identifying signal lights concurrently, reducing the expected keen competition for visual resources.

Characteristics of Tables for Disseminating Biobehavioral Results.

BACKGROUND: To report the complexity and richness of study variables within biological nursing research, authors often use tables; however, the ease with which consumers understand, synthesize, evaluate, and build upon findings depends partly upon table design. OBJECTIVES: To assess and compare table characteristics within research and review articles published in Biological Research for Nursing and Nursing Research. METHOD: A total of 10 elements in tables from 48 biobehavioral or biological research or review articles were analyzed. To test six hypotheses, a two-level hierarchical linear model was used for each of the continuous table elements, and a two-level hierarchical generalized linear model was used for each of the categorical table elements. Additionally, the inclusion of probability values in statistical tables was examined. RESULTS: The mean number of tables per article was 3. Tables in research articles were more likely to contain quantitative content, while tables in review articles were more likely to contain both quantitative and qualitative content. Tables in research articles had a greater number of rows, columns, and column-heading levels than tables in review articles. More than one half of statistical tables in research articles had a separate probability column or had probability values within the table, whereas approximately one fourth had probability notes. CONCLUSIONS: Authors and journal editorial staff may be generating tables that better depict biobehavioral content than those identified in specific style guidelines. However, authors and journal editorial staff may want to consider table design in terms of audience, including alternative visual displays.

Slant Perception Under Stereomicroscopy.

Objective These studies used threshold and slant-matching tasks to assess and quantitatively measure human perception of 3-D planar images viewed through a stereomicroscope. The results are intended for use in developing augmented-reality surgical aids. Background Substantial research demonstrates that slant perception is performed with high accuracy from monocular and binocular cues, but less research concerns the effects of magnification. Viewing through a microscope affects the utility of monocular and stereo slant cues, but its impact is as yet unknown. Method Participants performed in a threshold slant-detection task and matched the slant of a tool to a surface. Different stimuli and monocular versus binocular viewing conditions were implemented to isolate stereo cues alone, stereo with perspective cues, accommodation cue only, and cues intrinsic to optical-coherence-tomography images. Results At magnification of 5x, slant thresholds with stimuli providing stereo cues approximated those reported for direct viewing, about 12°. Most participants (75%) who passed a stereoacuity pretest could match a tool to the slant of a surface viewed with stereo at 5x magnification, with mean compressive error of about 20% for optimized surfaces. Slant matching to optical coherence tomography images of the cornea viewed under the microscope was also demonstrated. Conclusion Despite the distortions and cue loss introduced by viewing under the stereomicroscope, most participants were able to detect and interact with slanted surfaces. Application The experiments demonstrated sensitivity to surface slant that supports the development of augmented-reality systems to aid microscope-aided surgery.

Motion sickness.

Over 2000 years ago the Greek physician Hippocrates wrote, "sailing on the sea proves that motion disorders the body." Indeed, the word "nausea" derives from the Greek root word naus, hence "nautical," meaning a ship. The primary signs and symptoms of motion sickness are nausea and vomiting. Motion sickness can be provoked by a wide variety of transport environments, including land, sea, air, and space. The recent introduction of new visual technologies may expose more of the population to visually induced motion sickness. This chapter describes the signs and symptoms of motion sickness and different types of provocative stimuli. The "how" of motion sickness (i.e., the mechanism) is generally accepted to involve sensory conflict, for which the evidence is reviewed. New observations concern the identification of putative "sensory conflict" neurons and the underlying brain mechanisms. But what reason or purpose does motion sickness serve, if any? This is the "why" of motion sickness, which is analyzed from both evolutionary and nonfunctional maladaptive theoretic perspectives. Individual differences in susceptibility are great in the normal population and predictors are reviewed. Motion sickness susceptibility also varies dramatically between special groups of patients, including those with different types of vestibular disease and in migraineurs. Finally, the efficacy and relative advantages and disadvantages of various behavioral and pharmacologic countermeasures are evaluated.

Emergent features and perceptual objects: re-examining fundamental principles in analogical display design.

Two sets of design principles for analogical visual displays, based on the concepts of emergent features and perceptual objects, are described. An interpretation of previous empirical findings for three displays (bar graph, polar graphic, alphanumeric) is provided from both perspectives. A fourth display (configural coordinate) was designed using principles of ecological interface design (i.e. direct perception). An experiment was conducted to evaluate performance (accuracy and latency of state identification) with these four displays. Numerous significant effects were obtained and a clear rank ordering of performance emerged (from best to worst): configural coordinate, bar graph, alphanumeric and polar graphic. These findings are consistent with principles of design based on emergent features; they are inconsistent with principles based on perceptual objects. Some limitations of the configural coordinate display are discussed and a redesign is provided. Practitioner Summary: Principles of ecological interface design, which emphasise the quality of very specific mappings between domain, display and observer constraints, are described; these principles are applicable to the design of all analogical graphical displays.

Graphical displays for assessing covariate balance in matching studies.

RATIONALE, AIMS AND OBJECTIVES: An essential requirement for ensuring the validity of outcomes in matching studies is that study groups are comparable on observed pre-intervention characteristics. Investigators typically use numerical diagnostics, such as t-tests, to assess comparability (referred to as 'balance'). However, such diagnostics only test equality along one dimension (e.g. means in the case of t-tests), and therefore do not adequately capture imbalances that may exist elsewhere in the distribution. Furthermore, these tests are generally sensitive to sample size, raising the concern that a reduction in power may be mistaken for an improvement in covariate balance. In this paper, we demonstrate the shortcomings of numerical diagnostics and demonstrate how visual displays provide a complete representation of the data to more robustly assess balance. METHODS: We generate artificial datasets specifically designed to demonstrate how widely used equality tests capture only a single-dimension of the data and are sensitive to sample size. We then plot the covariate distributions using several graphical displays. RESULTS: As expected, tests showing perfect covariate balance in means failed to reflect imbalances at higher moments (variances). However, these discrepancies were easily detected upon inspection of the graphic displays. Additionally, smaller sample sizes led to the appearance of covariate balance, when in fact it was a result of lower statistical power. CONCLUSIONS: Given the limitations of numerical diagnostics, we advocate using graphical displays for assessing covariate balance and encourage investigators to provide such graphs when reporting balance statistics in their matching studies.

Cómo Mejorar la Comprensión de los Riesgos Médicos en Personas Mayores / How to Improve Comprehension of Medical Risks in Older Adults

Los mayores con frecuencia toman decisiones sobre su salud. A pesar de ello, prefieren adoptar un rol pasivo en este proceso. Una explicación que se ha ofrecido sobre este hecho es que frecuentemente presentan serias dificultades a la hora de comprender la información que reciben sobre los riesgos médicos. En un estudio, hemos investigado el grado en que los mayores (n=136) comprenden la información sobre la efectividad de los tratamientos médicos. Concretamente, hemos comparado la precisión de las inferencias que éstos realizan con los juicios en adultos jóvenes (n=121). Para ello, hemos presentado la información sobre la efectividad de los tratamientos en formato numérico o visual y hemos clasificado a los participantes según su nivel de habilidades gráficas. Nuestro estudio pone de manifiesto que la precisión de las inferencias que realizan los mayores se incrementa considerablemente cuando la información se representa visualmente. Esto ocurre especialmente cuando presentan habilidades gráficas elevadas. Concluimos que el uso de formatos visuales puede ser un método efectivo, transparente, y fiable de comunicación de la información sobre los riesgos médicos y la salud, y mencionamos las implicaciones prácticas de nuestros resultados para el desarrollo de campañas de salud.

Older adults frequently make decisions about their health. However, they prefer to play a passive role in this process. A plausible explanation of this result is that they often have difficulties understanding information about medical risks. In a study, we investigated the extent to what older adults (n=136) understand information about the effectiveness of medical treatments. In particular, we compared accuracy of their inferences to that of young adults (n=121). Participants were classified according to their graph literacy skills and received information about the effectiveness of medical treatments in a numerical or a visual format. Our study shows that visual aids substantially increased accuracy of inferences in older adults. Older adults with high graph literacy benefit most from the use of visual aids. We conclude that visual aids are often highly effective, transparent, and reliable risk communication tools. We discuss the practical implication of our results for the design of health campaigns.