magnocellular layer

The magnocellular (M) layers are part of the lateral geniculate nucleus (LGN) in the thalamus, which acts as a relay station for visual information on its way to the brain's cortex. The LGN contains six layers of cells; two of these are the larger-celled M layers, and the other four are smaller-celled parvocellular (P) layers. The M layers receive input from Y-cells in the retina, which have rapid responses but provide less detail and no color information. This pathway is primarily involved in guiding actions. In contrast, the P layers receive input from X-cells, which have slower responses but offer fine-grain resolution and strong color perception, and are thought to be involved in object identification.1