Thevisual cortex is a part of thebrain that allowsvision. It is relatively thin – between 1.5mm and 2mm inhumans. Inmonkeys andapes the visual cortex takes up much of theirbrain. Physically, the visual cortex is at the back of the brain in theoccipital lobe.
David Hubel andTorsten Wiesel did research on the visual cortex for many years. They won the 1981Nobel Prize in Physiology or Medicine for their discoveries about information processing in thevisual system.
Research on the primary visual cortex can involve recordingaction potentials fromelectrodes within the brain ofcats,ferrets,rats,mice, ormonkeys. Alternatively, signals can be recorded outside the animal byEEG,MEG, orfMRI. These techniques gather information without invading the brain.
The primary visual cortex (V1) is the best studied visual area in the brain. This is where the messages arrive from thelateral geniculate nuclei, which are relay stations for information from theretina. Each lateral geniculate nucleus gets signals from theopposite visual field.
Each V1 sends information to two primary pathways, called the ventral stream and the dorsal stream.