Editing Visual cortex (section)

==Introduction==
The primary visual cortex (V1) is located in and around the [[calcarine fissure]] in the [[occipital lobe]]. Each hemisphere's V1 receives information directly from its ipsilateral [[lateral geniculate nucleus]] that receives signals from the contralateral visual hemifield.

[[Neuron]]s in the visual cortex fire [[action potential]]s when visual stimuli appear within their [[receptive field]]. By definition, the receptive field is the region within the entire visual field that elicits an action potential. But, for any given neuron, it may respond best to a subset of stimuli within its receptive field. This property is called ''[[neuronal tuning]]''. In the earlier visual areas, neurons have simpler tuning. For example, a neuron in V1 may fire to any vertical stimulus in its receptive field. In the higher visual areas, neurons have complex tuning. For example, in the inferior temporal cortex (IT), a neuron may fire only when a certain face appears in its receptive field.

Furthermore, the arrangement of receptive fields in V1 is [[retinotopic]], meaning neighboring cells in V1 have receptive fields that correspond to adjacent portions of the visual field. This spatial organization allows for a systematic representation of the visual world within V1. Additionally, recent studies have delved into the role of contextual modulation in V1, where the perception of a stimulus is influenced not only by the stimulus itself but also by the surrounding context, highlighting the intricate processing capabilities of V1 in shaping our visual experiences.<ref>{{cite journal | vauthors = Fişek M, Herrmann D, Egea-Weiss A, Cloves M, Bauer L, Lee TY, Russell LE, Häusser M | title = Cortico-cortical feedback engages active dendrites in visual cortex | journal = Nature | volume = 617 | issue = 7962 | pages = 769–776 | date = May 2023 | pmid = 37138089 | pmc = 10244179 | doi = 10.1038/s41586-023-06007-6 | bibcode = 2023Natur.617..769F }}</ref>

The visual cortex receives its blood supply primarily from the [[calcarine artery|calcarine branch]] of the [[posterior cerebral artery]].

The size of V1, V2, and V3 can vary three-fold, a difference that is partially inherited.<ref name="Benson Yoon Forenzo Engel 2022">{{cite journal | vauthors = Benson NC, Yoon JM, Forenzo D, Engel SA, Kay KN, Winawer J | title = Variability of the Surface Area of the V1, V2, and V3 Maps in a Large Sample of Human Observers | journal = The Journal of Neuroscience | volume = 42 | issue = 46 | pages = 8629–8646 | date = November 2022 | pmid = 36180226 | pmc = 9671582 | doi = 10.1523/jneurosci.0690-21.2022 }}</ref>