Virtual reality (VR) is increasingly used in public speaking training, yet the distinct roles of environmental context and virtual audience design remain unclear. This study examines how avatar visual style (realistic vs. stylized) and scene type (natural vs. indoor) influence subjective experience and physiological stress. A total of 132 participants were assigned to a 2 × 2 between-subjects experiment. Subjective experience was assessed using standardized questionnaires, while physiological responses were measured via electrodermal activity and heart rate variability, complemented by post-experiment interviews. Results revealed a dissociation between subjective and physiological responses. Natural environments significantly enhanced user satisfaction and overall experience, whereas avatar style primarily influenced physiological stress. Specifically, stylized avatars elicited lower electrodermal activity than realistic avatars, indicating reduced sympathetic arousal. No significant interaction effects were observed. Mediation analyses showed no significant roles of perceived support or threat, suggesting that physiological responses may not rely on explicit cognitive appraisal. Qualitative findings further indicated that ambiguous audience feedback limited evaluative interpretation. These findings support a dual-pathway framework in which environmental context shapes cognitive–affective experience, whereas avatar realism modulates implicit physiological stress. This study provides theoretical insights and practical implications for designing VR systems that enhance user comfort and reduce stress.

Virtual agents powered by large language models are increasingly deployed in digital mental health services, yet the influence of avatar appearance on users’ emotional, cognitive, and physiological responses remains insufficiently understood. This study examined how three avatar designs—animal-like, human-like, and object-like—shape affective experience, user evaluation, autonomic activity, and attentional allocation during virtual doctor interactions. Forty-two participants completed a within-subjects experiment involving self-reported affect ratings, multidimensional user-experience assessments, heart rate variability (HRV) measures, and eye-tracking indicators. Avatar type did not significantly affect changes in positive or negative affect. However, physiological data revealed clear divergences. The animal-like avatar elicited the strongest parasympathetic activation, reflected by significant increases in RMSSD and HF power, whereas the object-like avatar produced a sympathetic-dominant response. Across six user-experience dimensions, the animal-like avatar consistently received the highest evaluations. Eye-tracking results showed faster first fixation and longer face-directed fixation duration for the animal-like avatar, indicating stronger social attention. The human-like avatar demonstrated slightly delayed initial fixation, consistent with subtle yet nonsignificant uncanny-valley tendencies. These findings underscore the critical role of avatar visual design in shaping emotional safety, engagement, and social processing in virtual mental health interactions.

Virtual agents powered by large language models are increasingly deployed in digital mental health services, yet the influence of avatar appearance on users’ emotional, cognitive, and physiological responses remains insufficiently understood. This study was conducted between March and April 2024 and examined how three avatar designs—animal-like, human-like, and object-like—shape affective experience, user evaluation, autonomic activity, and attentional allocation during virtual doctor interactions. Forty-two participants completed a within-subjects experiment involving self-reported affect ratings, multidimensional user-experience assessments, heart rate variability (HRV) measures, and eye-tracking indicators. The avatar type did not yield statistically significant differences in changes in positive or negative affect across conditions. However, physiological data revealed clear divergences. The animal-like avatar elicited the strongest parasympathetic activation, reflected by significant increases in the root mean square of successive differences (RMSSD) and high-frequency (HF) power, whereas the object-like avatar produced a sympathetic-dominant response. Across six user-experience dimensions, the animal-like avatar consistently received the highest evaluations. Eye-tracking results showed faster first fixation and a longer face-directed fixation duration for the animal-like avatar, indicating stronger social attention. The human-like avatar demonstrated slightly delayed initial fixation, consistent with subtle yet nonsignificant uncanny-valley tendencies. These findings underscore the critical role of avatar visual design in shaping emotional safety, engagement, and social processing in virtual mental-health interactions.