Effects of Virtual Pedagogical Agents and Instructional Content Type on Learners' Experience in Online Learning: Evidence from Behavioral, Eye-Tracking, and EEG Data.

Online learning has become an important means of acquiring knowledge. Virtual pedagogical agents have gradually evolved from auxiliary tools into intelligent instructional media capable of affective interaction. However, how these agents affect learning outcomes remains unclear. Integrating social agency theory and cognitive load theory, this study developed a model in which virtual pedagogical agent type was the independent variable; learning experience was the dependent variable; psychological distance, emotional attachment, and attentional engagement were mediators; and instructional content type was the moderator. A 2 (virtual pedagogical agent: human-like vs. non-human) × 2 (instructional content type: traditional knowledge vs. interest-oriented popular science) mixed design was used. Questionnaires, eye tracking, and electroencephalography (EEG) were combined to assess the learning processes of 40 university students. The results showed that the interaction between agent type and instructional content type significantly affected learning experience. Specifically, in learning contexts featuring traditional knowledge content, human-like virtual agents were associated with higher learning satisfaction, greater emotional attachment, and lower psychological distance. In contrast, during interest-oriented content learning, non-human agents achieved superior knowledge recall scores, along with higher learning satisfaction, stronger emotional attachment, and lower psychological distance. Furthermore, eye-tracking data showed that attentional allocation was also affected by this combination. EEG data showed that FCz spectral power varied with it as well, however, because power rose simultaneously in theta, alpha, beta, and gamma; this broadband pattern is not an unambiguous index of deeper processing and may partly reflect a general increase in signal amplitude. In addition, the moderated-mediation analysis revealed that psychological distance and emotional attachment mediated the relationship between virtual-agent type and learning experience, while knowledge type moderated these mediating paths. The practical implications for online learning are discussed.