Global InformationRetinotopy information
Retinotopy (from Greek τόπος (tópos) 'place') is the mapping of visual input from the retina to neurons, particularly those neurons within the visual stream. For clarity, 'retinotopy' can be replaced with 'retinal mapping', and 'retinotopic' with 'retinally mapped'.
Visual field maps (retinotopic maps) are found in many amphibian and mammalian species, though the specific size, number, and spatial arrangement of these maps can differ considerably. Sensory topographies can be found throughout the brain and are critical to the understanding of one's external environment. Moreover, the study of sensory topographies and retinotopy in particular has furthered our understanding of how neurons encode and organize sensory signals.
Retinal mapping of the visual field is maintained through various points of the visual pathway including but not limited to the retina, the dorsal lateral geniculate nucleus, the optic tectum, the primary visual cortex (V1), and higher visual areas (V2-V4). Retinotopic maps in cortical areas other than V1 are typically more complex, in the sense that adjacent points of the visual field are not always represented in adjacent regions of the same area. For example, in the second visual area (V2), the map is divided along an imaginary horizontal line across the visual field, in such a way that the parts of the retina that respond to the upper half of the visual field are represented in cortical tissue that is separated from those parts that respond the lower half of the visual field. Even more complex maps exist in the third and fourth visual areas V3 and V4, and in the dorsomedial area (V6). In general, these complex maps are referred to as second-order representations of the visual field, as opposed to first-order (continuous) representations such as V1.[1] Additional retinotopic regions include ventral occipital (VO-1, VO-2),[2] lateral occipital (LO-1, LO-2),[3] dorsal occipital (V3A, V3B),[4] and posterior parietal cortex (IPS0, IPS1, IPS2, IPS3, IPS4).[5]
- ^ Cite error: The named reference
Rosawas invoked but never defined (see the help page). - ^ Brewer AA, Liu J, Wade AR, Wandell BA (August 2005). "Visual field maps and stimulus selectivity in human ventral occipital cortex". Nature Neuroscience. 8 (8): 1102–9. doi:10.1038/nn1507. PMID 16025108. S2CID 8413534.
- ^ Larsson J, Heeger DJ (December 2006). "Two retinotopic visual areas in human lateral occipital cortex". The Journal of Neuroscience. 26 (51): 13128–42. doi:10.1523/jneurosci.1657-06.2006. PMC 1904390. PMID 17182764.
- ^ Tootell RB, Mendola JD, Hadjikhani NK, Ledden PJ, Liu AK, Reppas JB, Sereno MI, Dale AM (September 1997). "Functional analysis of V3A and related areas in human visual cortex". The Journal of Neuroscience. 17 (18): 7060–78. doi:10.1523/JNEUROSCI.17-18-07060.1997. PMC 6573277. PMID 9278542.
- ^ Silver MA, Ress D, Heeger DJ (August 2005). "Topographic maps of visual spatial attention in human parietal cortex". Journal of Neurophysiology. 94 (2): 1358–71. doi:10.1152/jn.01316.2004. PMC 2367310. PMID 15817643.