Presence vs. Anonymity tradeoff: Contextual influences of avatar visual fidelity on physiological and psychological responses

High-visual fidelity avatars are typically linked to increased realism and immersion, enhancing social presence and authentic interactions. This study explores how the context of conversations influences the impact of avatar visual fidelity on user experience. Using a 3 x 2 within-subject factorial design, 38 participants interacted with high-, medium-, and low-fidelity avatars during regular and sensitive conversations. Physiological metrics included Heart Rate Variability (HRV) and EEG, and the Perceived Stress Scale (PSS) measured psychological responses. HRV was measured using a Polar H10 chest wrap, with the LF/HF ratio reflecting autonomic nervous system activity. EEG data collected with a Muse headband were analyzed to compute Theta/Beta and Alpha/Beta ratios. Results showed that high-visual fidelity avatars induced higher stress levels, particularly during sensitive conversations, as indexed by increased LF/HF ratios and changes in EEG metrics. EEG metrics showed significant changes in Alpha/Beta ratios during sensitive conversations with high-visual fidelity avatars, reflecting potential increased cognitive and emotional stress. The study highlights a critical trade-off between presence and anonymity: high-visual fidelity enhances realism but can elevate stress during sensitive discussions, whereas lower fidelity may encourage a sense of anonymity and reduce social evaluation fears. These insights can inform the development of more effective virtual communication tools, particularly in fields such as mental health support, education, and remote work, where the context of interaction is crucial.