EEG-Based Engagement Monitoring in Cognitive Games

Cognitive decline and dementia prevention are global priorities, with cognitive rehabilitation games showing potential to delay their onset or progression. However, these games require sufficient user engagement to be effective. Assessing the engagement through questionnaires is challenging for the individuals suffering from cognitive decline due to age or dementia. This study aims to explore the relationship between game difficulty levels, three EEG engagement indices (beta/(theta + alpha), beta/alpha, 1/alpha), and the self-reported flow state scale score during video gameplay, and to develop an accurate machine learning algorithm for the classification of user states into high- and low-engagement. Twenty-seven participants (nine older adults) played a stunt plane video game while their EEG signals were recorded using EPOCX. They also completed the flow state scale for occupational tasks questionnaire after the easy, optimal, and hard levels of gameplay. Self-reported engagement scores significantly varied across the difficulty levels (p = 0.027), with the optimal level yielding the highest scores. Combining the three EEG indices achieved the best performance, with F1 scores of 89% (within-subject) and 81% (cross-subject). Engagement classification F1 scores were 90% for young adults and 85% for older adults. The findings provide preliminary data that supports using EEG data for engagement analysis in adults and older adults.