Source Distribution of Visual Evoked Neuromagnetic Responses

摘要

Visual contrast-onset-evoked magnetic fields were measured with a 122-channelmagnetometer covering the whole scalp. To facilitate the estimation of the spatial and temporal distribution of cortical generators, the responses were broken into two parts according to the dependence on the visual-field location of the stimulus. Minimum-norm estimates suggested that the generators for the part that was independent of the stimulus position were located in several occipital and extra-occipital regions, whereas the visual-field-dependent generators were predominantly in the occipital cortex. Our results support the view that information about the retinal image, even during passive viewing, is routed to several cortical areas.