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Control over an avatar in virtual reality can improve one's perceived sense of agency and embodiment towards their avatar. Yet, the relationship between control on agency and embodiment remains unclear. This work aims to investigate two main ideas: (1) the effectiveness of currently used metrics in measuring agency and embodiment and (2) the relationship between different levels of control on agency, embodiment, and cognitive performance. To do this, we conducted a between-participants user study with three conditions on agency ($\mathrm{n}=57$). Participants embodied an avatar with one of three types of control (i.e., Low - control over head only, Medium - control over head and torso, or High - control over head, torso, and arms) and completed a Stroop test. Our results indicate that the degree of control afforded to participants impacted their embodiment and cognitive performance but, as expected, could not be detected in the self-reported agency scores. Furthermore, our results elucidated further insights into the relationship between control and embodiment, suggesting potential uncanny valley-like effects. Future work should aim to refine agency measures to better capture the effect of differing levels of control and consider other methodologies to measure agency.

In a group setting, it is possible for attributes of one group member to indirectly affect how other group members are perceived. In this paper, we explore whether one group member's agency (e.g. if they are real or virtual) can indirectly affect behavior with other group members. We also consider whether variations in the agency of a group member directly affects behavior with that group member. To do so, we examined gaze behavior during a team training exercise, in which sixty-nine nurses worked with a surgeon and an anesthesiologist to prepare a simulated patient for surgery. The agency of the surgeon and the anesthesiologist were varied between conditions. Nurses' gaze behavior was coded using videos of their interactions. Agency was observed to directly affect behavior, such that participants spent more time gazing at virtual teammates than human teammates. However, participants continued to obey polite gaze norms with virtual teammates. In contrast, agency was not observed to indirectly affect gaze behavior. The presence of a second human did not affect participants' gaze behavior with virtual teammates.

In this paper we present a study exploring whether the physical presence of another human changes how people perceive and behave with virtual teammates. We conducted a study (n = 69) in which nurses worked with a simulated health care team to prepare a patient for surgery. The agency of participants' teammates was varied between conditions; participants either worked with a virtual surgeon and a virtual anesthesiologist, a human confederate playing a surgeon and a virtual anesthesiologist, or a virtual surgeon and a human confederate playing an anesthesiologist. While participants perceived the human confederates to have more social presence (p <; 0.01), participants did not preferentially agree with their human team members. We also observed an interaction effect between agency and behavioral realism. Participants experienced less social presence from the virtual anesthesiologist, whose behavior was less in line with participants' expectations, when a human surgeon was present.

We have created &#147;You, M.D.&#148;, an interactive museum exhibit in which users learn about topics in public health literacy while interacting with virtual humans. You, M.D. is equipped with a weight sensor, a height sensor and a Microsoft Kinect that gather basic user information. Conceptually, You, M.D. could use this user information to dynamically select the appearance of the virtual humans in the interaction attempting to improve learning outcomes and user perception for each particular user. For this concept to be possible, a better understanding of how different elements of the visual appearance of a virtual human affects user perceptions is required. In this paper, we present the results of an initial user study with a large sample size (n =333) ran using You, M.D. The study measured users&#146; reactions based on the user&#146;s gender and body-mass index (BMI) when facing virtual humans with BMI either concordant or discordant from the user&#146;s BMI. The results of the study indicate that concordance between the users&#146; BMI and the virtual human&#146;s BMI affects male and female users differently. The results also show that female users rate virtual humans as more knowledgeable than male users rate the same virtual humans.

Stressful interpersonal experiences can be difficult to prepare for. Virtual humans may be leveraged to allow learners to safely gain exposure to stressful interpersonal experiences. In this paper we present a between-subjects study exploring how the presence of a virtual human affected learners while practicing a stressful interpersonal experience. Twenty-six fourth-year medical students practiced performing a prostate exam on a prostate exam simulator. Participants in the experimental condition examined a simulator augmented with a virtual human. Other participants examined a standard unaugmented simulator. Participants reactions were assessed using self-reported, behavioral, and physiological metrics. Participants who examined the virtual human experienced significantly more stress, measured via skin conductance. Participants stress was correlated with previous experience performing real prostate exams; participants who had performed more real prostate exams were more likely to experience stress while examining the virtual human. Participants who examined the virtual human showed signs of greater engagement; non-stressed participants performed better prostate exams while stressed participants treated the virtual human more realistically. Results indicated that stress evoked by virtual humans is linked to similar previous real-world stressful experiences, implying that learners real-world experience must be taken into account when using virtual humans to prepare them for stressful interpersonal experiences.

Health sciences students often practice and are evaluated on interview and exam skills by working with standardized patients (people that role play having a disease or condition). However, standardized patients do not exist for certain vulnerable populations such as children and the intellectually disabled. As a result, students receive little to no exposure to vulnerable populations before becoming working professionals. To address this problem and thereby increase exposure to vulnerable populations, we propose using virtual humans to simulate members of vulnerable populations. We created a mixed reality pediatric patient that allowed students to practice pediatric developmental exams. Practicing several exams is necessary for students to understand how to properly interact with and correctly assess a variety of children. Practice also increases a student's confidence in performing the exam. Effective practice requires students to treat the virtual child realistically. Treating the child realistically might be affected by how the student and virtual child physically interact, so we created two object interaction interfaces - a natural interface and a mouse-based interface. We tested the complete mixed reality exam and also compared the two object interaction interfaces in a within-subjects user study with 22 participants. Our results showed that the participants accepted the virtual child as a child and treated it realistically. Participants also preferred the natural interface, but the interface did not affect how realistically participants treated the virtual child.

We investigate the efficacy of incorporating real-time feedback of user performance within mixed-reality environments (MREs) for training real-world tasks with tightly coupled cognitive and psychomotor components. This paper presents an approach to providing real-time evaluation and visual feedback of learner performance in an MRE for training clinical breast examination (CBE). In a user study of experienced and novice CBE practitioners (n = 69), novices receiving real-time feedback performed equivalently or better than more experienced practitioners in the completeness and correctness of the exam. A second user study (n = 8) followed novices through repeated practice of CBE in the MRE. Results indicate that skills improvement in the MRE transfers to the real-world task of CBE of human patients. This initial case study demonstrates the efficacy of MREs incorporating real-time feedback for training real-world cognitive-psychomotor tasks.

This paper presents Mixed Reality Humans (MRHs), a new type of embodied agent enabling touch-driven communication. Affording touch between human and agent allows MRHs to simulate interpersonal scenarios in which touch is crucial. Two studies provide initial evaluation of user behavior with a MRH patient and the usability and acceptability of a MRH patient for practice and evaluation of medical students' clinical skills. In Study I (n=8) it was observed that students treated MRHs as social actors more than students in prior interactions with virtual human patients (n=27), and used interpersonal touch to comfort and reassure the MRH patient similarly to prior interactions with human patients (n=76). In the within-subjects Study II (n=11), medical students performed a clinical breast exam on each of a MRH and human patient. Participants performed equivalent exams with the MRH and human patients, demonstrating the usability of MRHs to evaluate students' exam skills. The acceptability of the MRH patient for practicing exam skills was high as students rated the experience as believable and educationally beneficial. Acceptability was improved from Study I to Study II due to an increase in the MRH's visual realism, demonstrating that visual realism is critical for simulation of specific interpersonal scenarios.