“…P50 source localization studies have yielded mixed results, with various reports placing the origin of the P50 in the auditory cortex (Wood and Wolpaw, 1982;Weisser et al, 2001), hippocampus (Goff et al, 1980), reticular structures (Erwin and Buchwald, 1986), and frontal cortex (Weisser et al, 2001). Magnetoencephalographic data showed that the M50, the magnetic analog of the P50, was localized in the superior temporal gyri (Edgar et al, 2003). Sensory gating may be a multi-step process, with an early phase subserved by the temporo-parietal and prefrontal cortices and a later phase mediated by the hippocampus (Grunwald et al, 2003).…”