Electro-and magneto-encephalographic and event-related potential studies of visual processing in normals and neurological patients

This chapter provides an overview of non-invasive electrophysiological studies of the human visual system. It begins to explore the influences of passive visual stimulation using different stimuli, followed by a review of the effects of attention to location and other visual features on event-related brain potentials. It then considers recent findings linked to complex visual stimuli such as hierarchically structured objects and faces. A prevailing theme in experimental psychology is that selection of stimuli by the visual system is predominately obtained on the basis of location. Screening a complex visual scene for some relevant item or feature is a prerequisite for the survival of the individuum. It is shown that event-related potentials (ERPs) now provide a quite detailed picture of face-processing in humans. Event-related brain potentials, event-related magnetic fields, and induced activity are applied to track the fate of a visual stimulus on its way through the cortex.