Subject's own name as a novel in a MMN design: a combined ERP and PET study

With a view to elaborating a clinical tool to assess cognitive functions in brain-damaged patients, we had previously displayed characteristic patterns of ERPs (32 electrodes) in awake healthy persons in response to their own name (SON) presented as a novel in a passive oddball paradigm. In the present combined ERP and PET study, in an attempt to identify brain correlates of duration MMN and response to SON uttered by a familiar (FV) or an unknown voice (NFV), we used a block design protocol as close as possible to the aforementioned SON protocol. ERP data showed robust duration MMN and novelty P3 in response to SON similar to our previous results. The PET technique did not allow true MMN generators to be disclosed, but blocks with duration deviants elicited an increase of activation in the right temporal pole as compared with the control condition with no deviants, supporting the hypothesis of right hemispheric dominance in early sound discrimination. For SON contrasts, robust cerebral blood flow activation present over temporal, frontal and parietal cortices, in the hippocampus and in the precuneus could be associated with speech, novelty and self-recognition processing. Familiar and unfamiliar voices activated the prefrontal cortex differently, suggesting different retrieval processes, although corresponding ERP responses could not be differentiated.