Retinotopiska

Retinotopiska (retinotopy) describes the systematic organization by which visual information from the retina is represented in the brain. In a retinotopic map, neighboring cells respond to neighboring locations in the visual field, preserving the spatial layout seen by the observer.

In the primate visual system, the primary visual cortex (V1) contains a retinotopic map of the contralateral visual field. The fovea has a disproportionately large cortical representation, a phenomenon known as cortical magnification. Beyond V1, several extrastriate areas (V2, V3, V4, MT) maintain retinotopic maps, though with more complex transformations that integrate motion, color, and form.

Developmentally, retinotopic maps form as retinal ganglion cell axons project to the lateral geniculate nucleus and then to V1, guided by molecular cues to establish topographic continuity. In adults, retinotopic maps can be mapped noninvasively with functional imaging and visual stimulation, such as rotating wedges and expanding rings, or with electrophysiological recordings in animals and specialized methods like population receptive field modeling.

Clinical and research significance: Retinotopy provides a framework for understanding how the brain processes spatial information, for interpreting visual field deficits, and for studying cortical plasticity after injury or disease, including macular degeneration, glaucoma, and cortical lesions. It also underpins methods used to study visual perception and to map functional areas in the visual cortex.

See also: retinotopy, visual cortex, fMRI retinotopic mapping.