Visual attention towards virtual humans as a function of spatial distance and emotional expression: an eye-tracking study

During social interactions, the way people regulate the space between each other (i.e., the interpersonal distance) reflects the type and quality of the relationship existing between the interactants. Shorter interpersonal distances are for intimate relationships; larger interpersonal distances are for formal social interactions. Thus, we spontaneously choose the appropriate interpersonal distance to feel comfortable and avoid distress. Moreover, when interacting with other people or the environment, the space surrounding the body acts as a protective buffer against potential threats: this space is larger in unsafe situations, smaller in safe situations. Consistently, stimuli entering this area receive close attention and trigger approach or avoidance actions depending on the perceived level of danger. Therefore, one might wonder where people focus their gaze during social interactions to identify and appropriately react to the intentions of others, depending on spatial distance. Using eye-tracking technology in immersive virtual reality, this study sought to address this question by assessing how individuals shift their visual attention to different body parts as a function of the spatial distance (near, middle, far) and facial expression (happy, angry, neutral) of the interactants. Results showed that at near distances the gaze focuses on the faces of the interactant, while at far distances the whole body acquires importance. In the middle space, visual attention is especially drawn to angry interactants, with a focus on action-relevant effectors (i.e., arms). Therefore, the data suggest that spatial distances in social interactions modulate visual attention to specific body parts of the interactant to acquire information useful for preparing appropriate responses, especially when faced with a potential threat: far distances prompt the gathering of information about others (more attention to their whole body); near distances prioritize information about others' dispositions toward us (more attention to the face); middle distances facilitate preparation for action (more attention to effectors).