BackgroundThe human subcortical visual system is divided into distinct magnocellular, parvocellular and koniocellular pathways, which contribute differentially to specific aspects of early visual processing. Schizophrenia is associated with deficits in early-visual processing, especially involving N-methyl-D-aspartate receptor (NMDAR)-mediated non-linear gain within the subcortical magnocellular visual system. Nevertheless, methods for investigating the pathophysiological consequences remain lim