No significant improvement in short-term learning outcomes
Despite increased cognitive and self-reported engagement, participants using NeuroChat did not achieve higher scores on quizzes or essays compared to those using a standard chatbot. This is a critical limitation for an educational tool whose ultimate goal is to improve learning.
Short study duration and modest sample size
The study involved 20-minute learning sessions with a sample size of 24 participants. These parameters limit the generalizability of the findings and preclude strong claims about long-term learning outcomes, making it difficult to observe downstream effects on knowledge acquisition.
Ambiguity of EEG-derived engagement metric
The paper acknowledges that increased engagement, as measured by EEG, can also reflect cognitive overload, confusion, or frustration, rather than just productive learning. The system does not currently distinguish between these forms of engagement, which could lead to suboptimal adaptations.
Limitations of consumer-grade EEG signals
The Muse 2 EEG headband, while portable, has low spatial resolution, uses dry electrodes, and is highly sensitive to motion and muscle artifacts. These noise sources can distort engagement metrics and reduce the reliability of real-time inference, limiting the robustness of the neuroadaptive system.
Lack of explicit learner modeling and personalization
The current system modulates output based on general engagement levels but lacks awareness of individual preferences or learning goals. This resulted in varied user experiences, with some users preferring factual, concise responses over the adaptive chatbot's more conversational style.