Visual attention to wayfinding aids in virtual environments

Concepts of spatial navigation rest on the idea of landmarks, which are immobile features or objects in the environment. However, behaviorally relevant objects or fellow humans are often mobile. This raises the question of how the presence of human agents influences spatial exploration and knowledge acquisition. Here, we investigate exploration and performance in subsequent spatial tasks within a virtual environment containing numerous human avatars. In the exploration phase, agents had a locally limited effect on navigation. They prompted participants to revisit locations with agents during their initial exploration without significantly altering overall exploration patterns or the extent of the area covered. However, agents and buildings competed for visual attention. When spatial recall was tested, pointing accuracy toward buildings improved when participants directed their attention to the buildings and nearby agents. In contrast, pointing accuracy for agents showed weaker performance and did not benefit from visual attention directed toward the adjacent building. Contextual agents and incongruent agent-environment pairings further enhanced pointing accuracy, revealing that violations of expectations by agents can significantly shape navigational knowledge acquisition. Overall, agents influenced spatial exploration by directing attention locally, with the interaction between agent salience and environmental features playing a key role in shaping navigational knowledge acquisition.

How do we come to the decision that we like a face? This thesis investigates this important aspect of social processing and communication by examining preference decisions for faces and the role that visual behavior plays in the process. I present a series of studies designed to investigate face preference formation and gaze patterns using eye-tracking and self-reported preference ratings. I tested healthy control subjects and two clinical populations known to have deficits in social processing: people with autism and patients with amygdala lesions. In studies one and two, I explore whether known social cognition deficits in people with autism and amygdala lesions also impair subjective decision-making regarding the attractiveness of faces. In study three, I investigate the flexibility of rule-based visual strategies used by these populations during face perception. Additionally, I present a custom algorithm developed to process raw eyetracking data, which was used to analyze all eyetracking data in this thesis. People with autism and patients with amygdala lesions are known to have general deficits in social processing, including difficulty orienting toward and evaluating faces. Nevertheless, I find that their behavior is markedly similar in many areas where we would expect them to have abnormalities or deficiencies. Their preference decisions when judging facial attractiveness were highly correlated with those made by controls, and both groups showed the same biases for familiar faces over novel faces. In addition, people with autism exhibit the same visual sampling behavior linking preference and attentional orienting, but reach their decisions faster than controls and also appear insensitive to the difficulty of the choice. Finally, gaze to the eye region appears normal in the absence of an explicit decision-making task, but only when analyzed in a similar manner as previous studies. However, when face sub-regions were analyzed in greater detail, people with autism demonstrate abnormalities in face gaze patterns, failing to emphasize the most information-rich regions of the face. Furthermore, people with autism demonstrate impairments in their ability to update those gaze patterns to accommodate different viewing restrictions. Taken together, these findings support the idea that the normal formation of face preferences can be preserved in the presence of general social processing impairments. Patterns in the eyetracking and behavioral data indicate that this is made possible, in part, by compensatory atypical processing and visual strategies.

In this paper, we discuss the concept of autobiographic agent and how memory may extend an agent's temporal horizon and increase its adaptability. These concepts are applied to an implementation of a scenario where agents are interacting in a complex virtual artificial life environment. We present computational memory architectures for autobiographic virtual agents that enable agents to retrieve meaningful information from their dynamic memories which increases their adaptation and survival in the environment. The design of the memory architectures, the agents, and the virtual environment are described in detail. Next, a series of experimental studies and their results are presented which show the adaptive advantage of autobiographic memory, i.e. from remembering significant experiences. Also, in a multi-agent scenario where agents can communicate via stories based on their autobiographic memory, it is found that new adaptive behaviours can emerge from an individual's reinterpretation of experiences received from other agents whereby higher communication frequency yields better group performance. An interface is described that visualises the memory contents of an agent. From an observer perspective, the agents’ behaviours can be understood as individually structured, and temporally grounded, and, with the communication of experience, can be seen to rely on emergent mixed narrative reconstructions combining the experiences of several agents. This research leads to insights into how bottom-up story-telling and autobiographic reconstruction in autonomous, adaptive agents allow temporally grounded behaviour to emerge. The article concludes with a discussion of possible implications of this research direction for future autobiographic, narrative agents.

Reduction of Healthcare-Associated Infections (HAIs) by 83% in a long-term acute care setting (LTAC)

Understanding the principles involved in visually-based coordinated motor control is one of the most fundamental and most intriguing research problems across a number of areas, including psychology, neuroscience, computer vision and robotics. Not very much is known regarding computational functions that the central nervous system performs in order to provide a set of requirements for visually-driven reaching and grasping. Additionally, in spite of several decades of advances in the field, the abilities of humanoids to perform similar tasks are by far modest when needed to operate in unstructured and dynamically changing environments. More specifically, our first focus is understanding the principles involved in human visuomotor coordination. Not many behavioral studies considered visuomotor coordination in natural, unrestricted, head-free movements in complex scenarios such as obstacle avoidance. To fill this gap, we provide an assessment of visuomotor coordination when humans perform prehensile tasks with obstacle avoidance, an issue that has received far less attention. Namely, we quantify the relationships between the gaze and arm-hand systems, so as to inform robotic models, and we investigate how the presence of an obstacle modulates this pattern of correlations. Second, to complement these observations, we provide a robotic model of visuomotor coordination, with and without the presence of obstacles in the workspace. The parameters of the controller are solely estimated by using the human motion capture data from our human study. This controller has a number of interesting properties. It provides an efficient way to control the gaze, arm and hand movements in a stable and coordinated manner. When facing perturbations while reaching and grasping, our controller adapts its behavior almost instantly, while preserving coordination between the gaze, arm, and hand. In the third part of the thesis, we study the neuroscientific literature of the primates. We here stress the view that the cerebellum uses the cortical reference frame representation. The cerebellum by taking into account this representation performs closed-loop programming of multi-joint movements and movement synchronization between the eye-head system, arm and hand. Based on this investigation, we propose a functional architecture of the cerebellar-cortical involvement. We derive a number of improvements of our visuomotor controller for obstacle-free reaching and grasping. Because this model is devised by carefully taking into account the neuroscientific evidence, we are able to provide a number of testable predictions about the functions of the central nervous system in visuomotor coordination. Finally, we tackle the flow of the visuomotor coordination in the direction from the arm-hand system to the visual system. We develop two models of motor-primed attention for humanoid robots. Motor-priming of attention is a mechanism that implements prioritizing of visual processing with respect to motor-relevant parts of the visual field. Recent studies in humans and monkeys have shown that visual attention supporting natural behavior is not exclusively defined in terms of visual saliency in color or texture cues, rather the reachable space and motor plans present the predominant source of this attentional modulation. Here, we show that motor-priming of visual attention can be used to efficiently distribute robot's computational resources devoted to visual processing.

Through technological advancements, the use of virtual environments (VE) in education and training has increased. One challenge that users face is the task of navigation in virtual environments. This research investigates navigation within a virtual environment and how users utilize different navigational tools. Navigational tools are categorized as either active or passive, based on the type of information that they present. The goal of this study was to determine if there are differences in the ways that users use passive and active navigational tools. This study was conducted by collecting eye fixations and fixation durations while participants used a navigation tool in completing a task in a VE. Results revealed no significant difference between percentage of fixations and fixation durations and future research should investigate the comparison of active and passive navigational tools in more complex virtual environments.

Vision actively influences the gait, and older adults show altered visual patterns compared to their younger counterpart when approaching challenges in the travel path. Attentional distractors influence the motor strategies during obstacle crossing. In rehabilitation, treadmill and virtual reality (VR) are commonly used to train gait. The VR technology allows for repeatable, safe and full variable control tasks and is well accepted by the patients. The gaze behavior when watching at videos of a first perspective walking is similar to that adopted in the real world and the training of the gaze is effective to improve the accuracy of the gait. Therefore, the integration of the gaze monitoring in existing VR-based gait rehabilitation protocols could both give insights in the visuo-motor strategy adopted in challenging conditions and could improve the gait rehabilitation effectiveness. The research presented in this thesis consisted in the assessment of the visuo-motor strategies of young and older adults during obstacles crossing in a projected VR environment with visual distractors. The first part of the project consisted in testing a set-up allowing for such an assessment with a remote eye-tracking system. The tested remote eye-tracker was demonstrated to be reliable for treadmill walking, with gaze measurements comparable to those got for the static conditions. The second part of the project aimed at studying the effect of distractors during obstacle avoidance, by making young and older adults walking on a treadmill while navigating a purposely depicted VR world. Young and older adults showed different visual scan patterns of the scene. This study highlights the visuo-motor strategy of young and older adults in a set-up similar to those recently used in gait rehabilitation and showed that the two populations are distinguishable by the adopted visual strategy. This and further investigations are important to address better the gait rehabilitation interventions.

The performance levels of human subjects in size identification and size discrimination experiments in both real and virtual environments are presented. The virtual environments are displayed with a PHANToM desktop three degree-of-freedom haptic interface. Results indicate that performance of the size identification and size discrimination tasks in the virtual environment is comparable to that in the real environment, implying that the haptic device does a good job of simulating reality for these tasks. Additionally, performance in the virtual environment was measured at below maximum machine performance levels for two machine parameters. The tabulated scores for the perception tasks in a sub-optimal virtual environment were found to be comparable to that in the real environment, supporting previous claims that haptic interface hardware may be able to convey, for these perceptual tasks, sufficient perceptual information to the user with relatively low levels of machine quality in terms of the following parameters: maximum endpoint force and maximum virtual surface stiffness. Results are comparable to those found for similar experiments conducted with other haptic interface hardware, further supporting this claim. Finally, it was found that varying maximum output force and virtual surface stiffness simultaneously does not have a compounding effect that significantly affects performance for size discrimination tasks.

BackgroundInadequate situational awareness accounts for two-thirds of preventable complications in anesthesia. An essential tool for situational awareness in the perioperative setting is the patient monitor. However, the conventional monitor has several weaknesses. Avatar-based patient monitoring may address these shortcomings and promote situation awareness, a prerequisite for good decision making.ObjectiveThe spatial distribution of visual attention is a fundamental process for achieving adequate situation awareness and thus a potential quantifiable surrogate for situation awareness. Moreover, measuring visual attention with a head-mounted eye-tracker may provide insights into usage and acceptance of the new avatar-based patient monitoring modality.MethodsThis prospective eye-tracking study compared anesthesia providers' visual attention on conventional and avatar-based patient monitors during simulated critical anesthesia events. We defined visual attention, measured as fixation count and dwell time, as our primary outcome. We correlated visual attention with the potential confounders: performance in managing simulated critical anesthesia events (task performance), work experience, and profession. We used mixed linear models to analyze the results.ResultsFifty-two teams performed 156 simulations. After a manual quality check of the eye-tracking footage, we excluded 57 simulations due to technical problems and quality issues. Participants had a median of 198 (IQR 92.5-317.5) fixations on the patient monitor with a median dwell time of 30.2 (IQR 14.9-51.3) seconds. We found no significant difference in participants' visual attention when using avatar-based patient monitoring or conventional patient monitoring. However, we found that with each percentage point of better task performance, the number of fixations decreased by about 1.39 (coefficient –1.39; 95% CI –2.44 to –0.34; P=.02), and the dwell time diminished by 0.23 seconds (coefficient –0.23; 95% CI: –0.4 to –0.06; P=.01).ConclusionsUsing eye tracking, we found no significant difference in visual attention when anesthesia providers used avatar-based monitoring or conventional patient monitoring in simulated critical anesthesia events. However, we identified visual attention in conjunction with task performance as a surrogate for situational awareness.

1. Luis H. Ospina, MD* 1. *Assistant Professor, Pediatric Ophthalmology and Neuro-ophthalmology, Ste-Justine Hospital, University de Montreal, Montreal, Quebec, Canada After completing this article, readers should be able to: 1. Recognize cortical visual impairment (CVI) as an important cause of pediatric visual loss. 2. Identify the most frequent causes of pediatric CVI and, more specifically, understand the role of hypoxia as a cause of central visual damage. 3. Describe the different patterns and implications for future vision of hypoxic central visual damage occurring in preterm compared with term babies. 4. Know the clinical signs suggestive of CVI in children. 5. Discuss the involvement of visual functions other than visual acuity (ie, cognitive visual aspects) in CVI and correlate them with the likely affected neuroanatomic substrates. 6. Explain the value of using a multidisciplinary approach in rehabilitating children who have CVI early in their development. Vision loss caused by central nervous system damage often is referred to as CVI but also may be referred to as cerebral visual impairment or neurologic visual impairment. These terms refer to the fact that the primary defect may not necessarily be limited to the striate (primary visual) cortex and may affect other areas subserving vision, such as the visual associative cortex, optic radiations, and visual attention pathways. Although it is not yet certain which of these three terms best describes the visual deficit, it is clear that use of the label cortical blindness must be abandoned. That term not only evokes negative connotations for the child and the family but is inaccurate because in almost every instance, some degree of residual vision remains, and visual improvement can occur. CVI has become the greatest cause of pediatric visual impairment in developed countries (1)(2)(3)(4)(5) and is becoming increasingly prevalent in developing nations. CVI is a problem of increasing frequency for two primary reasons. First, the progress in neonatal care has resulted in improved survival of …

This study aimed to explore how a three-dimensional (3D) map affects the acquisition of survey knowledge in complex virtual environments (VEs). Subject navigated in virtual and real subway stations, where the virtual station was augmented with either a 3D floor map, a 3D building map, or neither. After subject's navigation in the station, they made the judgment of spatial relative directions between objects. The analyses of response time showed that participants responded faster when they were assisted by the 3D floor or building map than without a map aid in virtual stations. There was no significant difference between survey knowledge acquired in the virtual station augmented with the 3D floor or building map and in the real station. Participants with the 3D floor map performed best in spatial judgments. Implications of these findings to a 3D map design were discussed.

Learning the spatial layout of an environment is essential in application domains including military and emergency personnel training. Traditionally, whilst learning space from a Virtual Environment (VE), identical training time was used for all users - a one size fits all approach to exposure / training time. This chapter, however, identifies both environmental and individual user differences that influence the training time required to ensure effective virtual environment spatial knowledge acquisition (SKA). We introduce the problem of contradicting literature in the area of SKA, and discuss how the amount of exposure time given to a person during VE training is responsible for the feasibility of SKA. We then show how certain individual user differences, as well as environmental factors, impact on the required exposure time that a particular person needs within a specific VE. Individual factors discussed include: the importance of knowledge and experience; the importance of gender; the importance of aptitude and spatial orientation skills; and the importance of cognitive styles. Environmental factors discussed include: Size, Spatial layout complexity and landmark distribution. Since people are different, a one-size fits all approach to training time does not seem logical. The impact of this research domain is important to VE training in general, however within service and military domains ensuring appropriate spatial training is critical in order to ensure that disorientation does not occur in a life / death scenario.

In this article, we address the central topic of the call for papers, childhood educates space, from the perspective of children’s and young people’s spatial knowledge. We argue that both childhood and youth educate as much as are educated by space. To shed light on this dynamic and complex interaction, we focus on the arenas and agencies at play within the production and acquisition of spatial knowledge. The term arena refers to the spatial conditions that delineate an area of activity related to the production and acquisition of spatial knowledge, and agency denotes the crucial means, agents, and tools that are instrumental in and buttress such area of activity. To render operative the analysis, we draw on two driving themes: (i) the gradual development of a comprehensive conception of space and (ii) its accompanying (and traversing) learning processes. Moreover, to substantiate the assertion that education between childhood and youth and space is mutually constitutive, we present a selection of findings from a qualitative meta-analysis conducted to reconstruct the evolution of young people’s spatial knowledge from the 1970s onwards. All in all, we claim that the process of production and acquisition of spatial knowledge forms the basis of, on the one hand, the keenness and depth of the perception that children and young people have of the physical world and, on the other, the ways they subjectively and symbolically characterize it.

Observation of Food Handlers’ Hand Hygiene Behavior During Production at a Sandwich-making Factory

Online retailers are challenged to present their products in an appropriate way to attract customers’ attention. To test the impact of product presentation features on customers’ visual attention, webcam eye tracking might be an alternative to infrared eye tracking, especially in situations where face-to-face contact is difficult. The aim of this study was to examine whether webcam eye tracking is suitable for investigating the influence of certain exogenous factors on customers’ visual attention when visiting online clothing shops. For this purpose, screenshots of two websites of two well-known online clothing retailers were used as stimuli. Linear regression analyses were conducted to determine the influence of the spatial position and the presence of a human model on the percentage of participants visiting a product depiction. The results show that products presented by human models and located in the upper middle area of a website were visited by more participants. From this, we were able to derive recommendations for optimising product presentation in online clothing shops. Our results fit well with those of other studies on visual attention conducted with infrared eye tracking, suggesting that webcam eye tracking could be an alternative to infrared eye tracking, at least for similar research questions.