Spatiotemporal cortical activation underlying self-referencial processing evoked by self-hand.

Event-related potentials (ERPs) were recorded to explore the electrophysiological correlates of self-referencial processing when subjects were asked to judge whether the stimuli (their hands) were their own or not. ERP results showed that: first, own hand elicited a greater positive component (P350-500) than did other hand in the time window of 350-500 ms, and the generator of P350-500 was localized in the anterior cingulate cortex (ACC), which might be related to retrieval and identification of self-referencial information due to their sensitivity to self-hand. Second, own hand elicited a more positive component (LPC) than did other hand in the later time window. Dipole analysis revealed that the generators were localized in the parahippocampal gyrus and the medial frontal gyrus, which might be involved in making a self-referencial decision based on retrieval of self-hand information.