EEG and ANS markers of attention response in vegetative state: Different responses to own vs. other names

Covert measures of information-processing are valuable tools to support assessment of patients' disorders of consciousness because of their potential in revealing what seem to be hidden. Those measures allow to overcome some limitations of traditional behavioural methods, which are often biased by difficulties in detecting reliable patients' responses. Therefore, we aimed at exploring patterns of psychophysiological responses (electroencephalography - EEG, skin conductance level - SCL, skin conductance response - SCR, heart rate - HR) marking potentially-preserved processing of personally-relevant stimuli in a sample of VS patients. In particular, we compared the processing of own vs. other names due to the intrinsic salience, relevance, and familiarity of such stimuli. Analysis of electroencephalography, skin conductance and heart rate modulations highlighted a consistent pattern of increased skin conductance and heart rate measures in response to patients' own name with respect to other names. Further, we observed increased delta and decreased alpha activity over frontal areas in response to their own name with respect to other names. Own-name stimuli might preserve their peculiar qualification even after severe brain damage and might call on residual attention orientation and preferred coding resources, suggesting the existence of partly preserved information-processing pathways that extends beyond basic auditory sensory processing.