Friday, June 12, 2009

Primary Visual Cortex

The primary visual cortex is situated in the occipital lobe of the brain, in and around the calcarine fissure. It is anatomically equivalent to Brodmann area 17. The primary visual cortex receives information from the lateral geniculate nucleus and transmits information to two primary pathways, which are called the dorsal stream and the ventral stream.

Neurons in the primary visual cortex fire action potentials when visual stimuli appear within their receptive field. But for any given neuron, it may respond to a subset of stimuli within its receptive field. This property is called neuronal tuning. The visual cortex receives its blood supply primarily from the calcarine branch of the posterior cerebral artery.