Primary visual cortex functions & V1 neurons
The primary visual cortex is the most studied area of vision in the brain. In mammals, it is located in the posterior pole of the occipital lobe and is the simplest, earliest cortical field of view. It is highly specialized in processing information about static and moving objects and is perfectly suited for pattern recognition.
primary visual cortex functions
The functionally defined visual cortex is approximately equivalent to an anatomically defined striated cortex [desired clarity] The name “striate cortex” derives from the Gennari line, a characteristic bar visible to the naked eye, which represents myelinated axons with a lateral thorny body ending with a gray matter layer 4.
The primary visual cortex functions divide into six functionally distinct layers, the number from 1 to 6. Layer 4, which receives the most visual contribution from the lateral nucleus. It further divides into 4 layers, designated 4A, 4B, 4Cα, and 4Cβ. Sublamina 4Cα mainly receives the magnocellular input data from the LGN, whereas the 4Cβ layer receives input data from the intercellular pathways.
The average number of neurons in the primary human cortex on each hemisphere was estimated at around 140 million.
V1 has a very well-defined spatial information map in the vision. For example, in humans, the upper edge of the calcarine furrow reacts strongly to the lower half of the field of vision (below the center).
The lower edge of the calcarine to the upper half of the field of view. In the concept, this retinotopic mapping is a transformation of the visual image from the retina to V1.
The relationship between a given location in V1 and the subjective field of view is very precise. The dead fields maps in V1. When it comes to evolution, this correspondence is very simple and occurs in most animals with V1. In humans a retinal cavity, a large portion of V1 maps to a small. The central part of the field of view, a phenomenon known as cortical enlargement.
Perhaps for the purpose of precise spatial coding, the neurons in V1 have the smallest size of the reception field in any of the microscopic regions of the primary visual cortex functions.
The tuning properties of V1 neurons (which neurons react to) vary significantly over time. Early (40 ms and beyond) individual V1 neurons have strong tuning to a small set of stimuli. This means that neuronal responses can distinguish small changes in visual orientations, spatial frequencies, and colors.
In addition, individual V1 neurons in humans and animals with binocular vision have ocular dominance. It namely fine-tuning to one of two eyes. In V1 and the primary sensory cortex in general, neurons with similar tuning properties tend to merge together in cortical columns.
David Hubel and Torsten Wiesel proposed a classic model for the organization of ice cubes in cortical columns for two tuning properties: dominance and eye orientation. However, this model can not accommodate color, spatial frequency and many other features to which neurons are tuned.