Magnocellular pathway impairment in schizophrenia: evidence from functional magnetic resonance imaging.

摘要: Sensory processing deficits in schizophrenia have been documented for several decades, but their underlying neurophysiological substrates are still poorly understood. In the visual system, pattern of pathophysiology reported studies is suggestive dysfunction within magnocellular pathway beginning early sensory cortex or even subcortically. The present study used functional magnetic resonance imaging to investigate further bases and particular potential role stream dysfunction. Sinusoidal gratings systematically varying spatial frequency content were presented subjects at low high levels contrast differentially bias activity parvocellular pathways based on well established differences neuronal response profiles. Hemodynamic responses elicited by different frequencies mapped over occipital lobe then entire brain. Retinotopic mapping was localize activations with respect boundaries areas V1 V2, which demarcated each subject. Relative control subjects, patients showed markedly reduced low, not high, multiple regions occipital, parietal, temporal lobes. These findings support hypothesis that associated impaired functioning suggest these may contribute higher-order cognitive working memory, executive functioning, attention.