This research endeavor aims to measure and examine the phenomena of shooter bias using virtual reality. Shooter bias is a form of implicit bias when an individual has attitudes toward people or associates stereotypes with them without that individual’s conscious knowledge. We posit that virtual reality is a uniquely powerful tool for studying shooter bias because it allows complete control over what participants see and facilitates precise data collection. For this study, we used eye-tracking. We examine what participants looked at during a series of virtual decision tasks with the intention of correlating this information with the phenomena of shooter bias. Our results provide some insights into detecting moments of shooter bias in the virtual environment. Experimental results indicate that participants spent more time looking at Black virtual human (VH) agents over White virtual human agents and took longer to make decisions when the agent of interest was Black.

This paper presents a within-subject study to investigate the effects of leading and following behaviors on user visual attention behaviors when collaborating with a virtual agent (VA) during performing transportation tasks in immersive virtual environments. The task was to carry a target object from a location to a predefined location. There were two conditions, namely leader VA (LVA) and follower VA (FVA). The leader gave instructions to the follower to perform actions. In the FVA condition, users played the leader role, while they played the follower role in the LVA condition. The users and the VA communicated via spoken language. During the experiment, participants wore a head-mounted display and performed real walking in a room. In each condition, each participant performed 20 trials of object transportation for different types of objects. Our preliminary results revealed significant differences in the user visual attention behaviors between the follower and leader VA conditions during the transportation tasks.

Distance compression, which refers to the underestimation of ego-centric distance to objects, is a common problem in immersive virtual environments. Besides visually compensating the compressed distance, several studies have shown that auditory information can be an alternative solution for this problem. In particular, reverberation time (RT) has been proven to be an effective method to compensate distance compression. To further explore the feasibility of applying audio information to improve distance perception, we investigate whether users’ egocentric distance perception can be calibrated, and whether the calibrated effect can be carried over and even sustain for a longer duration. We conducted a study to understand the perceptual learning and carryover effects by using RT as stimuli for users to perceive distance in IVEs. The results show that the carryover effect exists after calibration, which indicates people can learn to perceive distances by attuning reverberation time, and the accuracy even remains a constant level after 6 months. Our findings could potentially be utilized to improve the distance perception in VR systems as the calibration of auditory distance perception in VR could sustain for several months. This could eventually avoid the burden of frequent training regimens.

We examined the effects on users during collaboration with two types of virtual human (VH) agents in object transportation in an immersive virtual environment or virtual reality (VR). The two types of virtual humans we examined are leader and follower agents. The goal of the users is to interact with the agents using natural language and carry objects from initial locations to destinations. In each trial, the follower agent follows a user’s instructions to perform actions to manipulate the object. The leader agent determines the appropriate actions that the agent and the user should perform. We developed a system which enabled users and virtual agents to carry objects in an intuitive manner. We conducted a within-subjects study to evaluate the user behaviors under two conditions: (LVH) interaction with a leader virtual human and (FVH) interaction with a follower virtual human. We found that the participants in LVH required a higher workload than that in FVH. However, the users’ experiences, game experiences, and users’ impressions between the two conditions were not significantly different.

This investigation compared the impact on the users’ non-verbal behaviors elicited by interacting with a crowd of emotional virtual humans (VHs) in native and non-native language settings. In a between-subject experiment, we collected objective metrics regarding the users’ behaviors during interaction with a crowd of VHs who expressed verbal and non-verbal communicative behaviors in response to users’ speech-based interaction. The study presented four VH crowd conditions based on their emotional disposition, namely Positive, Negative, Neutral, and Mixed, in accordance with which VHs exhibited the appropriate behaviors. Participants were tasked with collecting items in a virtual flea market, and they interacted using natural speech-based dialogue with the VHs. The language conditions were collected in the USA and under two different conditions in Taiwan. The participants in the USA group interacted with the VHs in English (a native language for the USA setting); and two different groups in Taiwan interacted with the VHs in either a foreign (English) or native (Mandarin) language, respectively. Results reveal that in the (TMA, TEN) and (UEN, TEN) conditions, native versus non-native language communication can alter social behaviors (e.g., interaction time) of participants towards virtual interlocutors. Our results also revealed strong effects of cultural differences on participants’ non-verbal social behaviors with VHs in the UEN and TMA conditions.

In this contribution, we empirically investigated the effect of small talk on the users' non-verbal behaviors and emotions when users interacted with a crowd of virtual humans (VHs) with positive behavioral dispositions. Users were tasked with collecting items in a virtual marketplace via natural speech-based dialogue with a crowd of virtual pedestrians and vendors. The users were able to engage in natural speech-based conversation in a predefined corpus of small talk content that covered various commonplace small talk topics such as conversations about the weather, general concerns, and entertainment based on similar real-life situations. For instance, the VHs with the small talk ability would ask the users some simple questions to make small talk or remind the users of their belongings. We conducted a between-subjects empirical evaluation to investigate whether the user behaviors and emotions were different between a small talk condition and a non-small talk condition, and examined gender effects of the participants. We collected objective and subjective measures of the users to analyze users' emotions and social interaction behaviors, when in conversation with VHs that either possessed small-talk capability or not, besides task or goal oriented dialogue capabilities. Our result revealed that the VHs with small talk capability could alter the emotions and non-verbal behaviors of the users. Furthermore, the non-verbal behaviors between female and male participants differed greatly in the presence or absence of small talk.

This investigation compared the emotional impact caused by a crowd of affective virtual humans (VHs) that communicated in the users' native or foreign language. We evaluated the users' affective reactions to a crowd of VHs that exhibited distinct emotional expressions. A total of four emotions were presented, which were Positive, Negative, Neutral, and Mixed. The VHs performed verbal and non-behaviors accordingly. Under the Mixed condition, the VHs were divided into three groups equally and each group was uniquely assigned one of the three emotions (i.e., positive, negative, and neutral). Users collected ten items from a virtual reality market. To complete the tasks, they interacted using natural speech with the emotional VHs. Three language conditions were investigated: one condition in USA and another two conditions in Taiwan. The group of participants in USA interacted with the VHs in English; and the two groups of participants in Taiwan interacted with the VHs using a foreign (English) language and a native (Mandarin) language respectively. We discovered that the medium of communication or language familiarity had a strong influence on participants' emotional reactions. When participants interacted in a foreign language with VHs with a positive emotional disposition, we found their positive emotional reactions were subdued and negative reactions were elevated. However, this was not the case when participants interacted with VHs in their native language, as their emotional reactions were contingent on the emotional disposition of the VHs.

No abstract available.

Cybersickness (CS) is one of the challenges that has hindered the widespread adoption of Virtual Reality and its applications. Consequently, a number of studies have focused on extensively understanding and reducing CS. Inspired by previous work that has sought to reduce CS using foveated rendering and Field of View (FOV) restrictions, we investigated how the presence and size of a static central window in peripheral FOV blurring affects CS. To facilitate this peripheral FOV blur, we applied a Gaussian blur effect in the display peripheral region, provisioning a full-resolution central window. Thirty participants took part in a three-session, within-subjects experiment, performing search and spatial updating tasks in a first-person, slow-walking, maze-traveling scenario. Two different central window sizes (small and large) were tested against a baseline condition that didn’t feature display peripheral blurring. Results revealed that the baseline condition produced higher levels of CS than both conditions with a central window. While there were no significant differences between the small and large windows, we observed interaction effects suggesting an influence of window size on “adaptation to CS.” When the central window is small, adaptation to CS seems to take more time but is more pronounced. The interventions had no effect on spatial updating and presence, but were detectable when the blurred area was larger (small central window). Lower sickness levels observed in both window conditions supports the use of peripheral FOV blurring to reduce CS, reducing our dependence on eye tracking. This being said, researchers must strive to find the right balance between window size and detectability to ensure seamless virtual experiences.

Research has shown that self-avatars (life-size representations of the user in Virtual Reality (VR)) can affect how people perceive virtual environments. In this paper, we investigated whether the visual fidelity of a self-avatar affects reach boundary perception, as assessed through two variables: 1) action taken (or verbal response) and 2) correct judgment. Participants were randomly assigned to one of four conditions: i) high-fidelity self-avatar, ii) low-fidelity self-avatar, iii) no avatar (end-effector), and iv) real-world as reference task group. Results indicate that all three VR viewing conditions were significantly different from real world in regards to correctly judging the reachability of the target. However, based on verbal responses, only the "no avatar" condition had a non-trivial difference with real world condition. Taken together with reachability data, participants in "no avatar" condition were less likely to correctly reach to the reachable targets. Overall, participant performance improved after completing a calibration phase with feedback, such that correct judgments increased and participants reached to fewer unreachable targets.

Immersive Virtual Environments (IVEs) are becoming more accessible and more widely utilized for training. Previous research has shown that the matching of visual and proprioceptive information is important for calibration. While research has demonstrated that self-avatars can enhance ones' sense of presence and improve distance perception, the effects of self-avatar fidelity on near field distance estimations has yet to be investigated. This study tested the effect of avatar fidelity on the accuracy of distance estimations in the near-field. Performance with a virtual avatar was also compared to real-world performance. Three levels of fidelity were tested; 1) an immersive self-avatar with realistic limbs, 2) a low-fidelity self-avatar showing only joint locations, and 3) end-effector only. The results suggest that reach estimations become more accurate as the visual fidelity of the avatar increases, with accuracy for high fidelity avatars approaching real-world performance as compared to low-fidelity and end-effector conditions. In all conditions reach estimations became more accurate after receiving feedback during a calibration phase.

No abstract available.

In an initial study, we characterized the properties of human reach motion in the presence or absence of visuo-haptic feedback in real and Immersive Virtual Environments (IVEs) or virtual reality within a participant’s maximum arm reach. Our goal is to understand how physical reaching actions to the perceived location of targets in the presence or absence of visuo-haptic feedback are different between real and virtual viewing conditions. Typically, participants reach to the perceived location of objects in the three-dimensional (3D) environment to perform selection and manipulation actions during 3D interaction in applications such as virtual assembly or rehabilitation. In these tasks, participants typically have distorted perceptual information in the IVE as compared to the real world, in part due to technological limitations such as minimal visual field of view, resolution, latency, and jitter. In an empirical evaluation, we asked the following questions: (i) how do the perceptual differences between virtual and real world affect our ability to accurately reach to the locations of 3D objects, and (ii) how do the motor responses of participants differ between the presence or absence of visual and haptic feedback? We examined factors such as velocity and distance of physical reaching behavior between the real world and IVE, both in the presence or absence of visuo-haptic information. The results suggest that physical reach responses vary systematically between real and virtual environments, especially in situations involving the presence or absence of visuo-haptic feedback. The implications of our study provide a methodological framework for the analysis of reaching motions for selection and manipulation with novel 3D interaction metaphors and to successfully characterize visuo-haptic versus non-visuo-haptic physical reaches in virtual and real-world situations.

Realistic versus stylized depictions of virtual humans in simulated inter-personal situations and their ability to elicit emotional responses in users has been an open question for artists and researchers alike. We empirically evaluated the effects of near visually realistic vs. non-realistic stylized appearance of virtual humans on the emotional response of participants in a medical virtual reality system that was designed to educate users in recognizing the signs and symptoms of patient deterioration. In a between-subjects experiment protocol, participants interacted with one of three different appearances of a virtual patient, namely visually realistic, cartoon-shaded and charcoal-sketch like conditions in a mixed reality simulation. Emotional impact were measured via a combination of quantitative objective measures were gathered using skin Electrodermal Activity (EDA) sensors, and quantitative subjective measures such as the Differential Emotion Survey (DES IV), Positive and Negative Affect Schedule (PANAS), and Social Presence questionnaire. The emotional states of the participants were analyzed across four distinct time steps during which the medical condition of the virtual patient deteriorated (an emotionally stressful interaction), and were contrasted to a baseline affective state. Objective EDA results showed that in all three conditions, male participants exhibited greater levels of arousal as compared to female participants. We found that negative affect levels were significantly lower in the visually realistic condition, as compared to the stylized appearance conditions. Furthermore, in emotional dimensions of interest-excitement, surprise, anger, fear and guilt participants in all conditions responded similarly. However, in social emotional constructs of shyness, presence, perceived personality, and enjoyment-joy, we found that participants responded differently in the visually realistic condition as compared to the cartoon and sketch conditions. Our study suggests that virtual human appearance can affect not only critical emotional reactions in affective inter-personal training scenarios. but also users' perceptions of personality and social characteristic of the virtual interlocutors.

We report the results of an empirical evaluation to examine the carryover effects of calibrations to one of three perturbations of visual and proprioceptive feedback: i) Minus condition (-20% gain) in which a visual stylus appeared at 80% of the distance of a physical stylus, ii) Neutral condition (0% gain) in which a visual stylus was co-located with a physical stylus, and iii) Plus condition (+20% gain) in which the visual stylus appeared at 120% of the distance of the physical stylus. Feedback was shown to calibrate distance judgments quickly within an IVE, with estimates being farthest after calibrating to visual information appearing nearer (Minus condition), and nearest after calibrating to visual information appearing further (Plus condition).

Research in visuo-motor coupling has shown that the matching of visual and proprioceptive information is important for calibrating movement. Many state-of-the art virtual reality (VR) systems, commonly known as immersive virtual environments (IVE), are created for training users in tasks that require accurate manual dexterity. Unfortunately, these systems can suffer from technical limitations that may force de-coupling of visual and proprioceptive information due to interference, latency, and tracking error. We present an empirical evaluation of how visually distorted movements affects users' reach to near field targets using a closed-loop physical reach task in an IVE. We specifically examined the recalibration of movements when the visually reached distance is scaled differently than the physically reached distance. Subjects were randomly assigned to one of three visual feedback conditions during which they reached to target while holding a tracked stylus: i) Condition 1 (-20% gain condition) in which the visual stylus appeared at 80% of the distance of the physical stylus, ii) Condition 2 (0% or no gain condition) in which the visual stylus was co-located with the physical stylus, and iii) Condition 3 (+20% gain condition) in which the visual stylus appeared at 120% of the distance of the physical stylus. In all conditions, there is evidence of visuo-motor calibration in that users' accuracy in physically reaching to the target locations improved over trials. During closed-loop physical reach responses, participants generally tended to physically reach farther in condition 1 and closer in condition 3 to the perceived location of the targets, as compared to condition 2 in which participants' physical reach was more accurate to the perceived location of the target.

We present a set of demonstrations of current work in the Clemson University Virtual Environments Group involving the development and testing of interactive virtual environments for applications in training, rehabilitation and workforce development. All of these applications are designed to leverage commodity hardware such as HDTVs, game controllers, and the Kinect sensor.