Highlights d Narrative stimuli can synchronize fluctuations of heart rate between individuals d This interpersonal synchronization is modulated by attention and predicts memory d These effects on heart rate cannot be explained by modulation of respiratory patterns d Synchrony is lower in patients with disorders of consciousness

A. Methodological considerations 1. Auditory oddball paradigm 2. Effect size measures B. Supplementary results 1. Population description (Figure S1, Table S1 and Table S2) 2. Other resting state EEG markers according to tDCS response ( Fig S2) 3. Resting state EEG markers according to the state of consciousness before stimulation (Fig S3) 4. Auditory oddball paradigm according to the state of consciousness before stimulation (Fig S4) 5. Auditory oddball paradigm in each groups (Fig S5) 6. Segmentation procedure example (Fig S6) C. References