Anterior cingulate activity and the self in disorders of consciousness.

Objectives: The aim of this study was to investigate the relationship between medial cortical activation and the presence of self and consciousness in healthy subjects and patients with vegetative state and minimally conscious state using functional magnetic resonance imaging (fMRI).

Experiment Design: We first conducted two fMRI experiments in healthy subjects to identify brain regions specifically associated with self-perception through the use of different auditory stimuli that had different grades of self-relatedness. We then applied these regions as functional localizers to examine the relationship between neural activity changes during self-relatedness and consciousness level in the patients with disorders of consciousness (DOC).

Mismatch negativity to the patient's own name in chronic disorders of consciousness.

Previous studies implicated potential value of mismatch negativity (MMN) in predicting recovery of consciousness in patients with disorders of consciousness (DOC). We have adopted a novel MMN evoked by subject's own name (SON), a self-referential stimulus thought to be powerful in evoking residual brain activity, and examined the correlation between the MMN and recovery of consciousness in patients with chronic (>1 month) DOC. Twelve patients and 12 age-matched healthy controls were investigated.