Identifying relevant EEG features for personalized emotional videos: a cross-population analysis in healthy controls and patients with disorders of consciousness

• Seventeen EEG features distinguished responses to emotional, personal videos. • Fuzzy entropy, CSP, and Hjorth activity showed top performance in healthy controls. • 47% of patients with DOC performed significantly in at least one HC model. • Patient testing performance generally aligned with their clinical diagnosis. • Some patients with DOC showed neural patterns partially similar to healthy controls. Emerging evidence suggests that personalized emotional stimuli can elicit measurable brain responses indicative of cognitive processing. This could be particularly relevant in patients with disorders of consciousness (DOC), where accurate assessment remains remarkably challenging. Despite this, the electroencephalography (EEG) features most sensitive to these personalized emotional stimuli, and their generalizability from healthy individuals to patients with DOC, remain underexplored. This study aimed to identify EEG features distinguishing brain responses to familiar versus non-familiar audiovisual stimuli in healthy controls and to assess their applicability in patients with DOC. Nineteen healthy controls and nineteen patients with DOC viewed personalized emotional videos featuring either familiar or unfamiliar individuals while EEG data were recorded. Seventeen EEG features across various domains were compared using subject-independent machine-learning models in healthy controls, and the top-performing features were validated in patients with DOC. Results indicated fuzzy entropy, common spatial pattern (CSP), and Hjorth activity were the most discriminative features. Applying models trained on healthy individuals to patients with DOC revealed statistically significant performances in 60% of patients in minimally conscious state and 33% of patients with unresponsive wakefulness syndrome. Topographical analyses identified prominent differences in temporal, parietal, and frontal regions within beta and gamma bands for healthy controls, partially replicated in responsive patients. These findings underscore fuzzy entropy, CSP, and Hjorth activity as sensitive EEG markers for detecting emotional responses to personalized videos in healthy controls. Their partial generalization to patients with DOC highlights potential clinical utility in assessing residual cognitive processing and consciousness, particularly in responsive states.