Visual cortex
202211201940
Status:
Tags: Neuroanatomy Vision
DEFINITION
An area of the cerebral cortex that processes visual information. It’s located in the occipital cortex. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches visual cortex. Both hemispheres include a visual cortex, where left hemisphere receives input from right visual field, and vice versa.
Primary Visual Cortex (V1)
Otherwise known as V1, the primary visual cortex takes in sensory information from the lateral geniculate nucleus in the thalamus and starts the processing for visual input. This region is also called the striate cortex, while V2/3/4/5 are considered to be part of the extrastriate area.
V1 is located in and around the calcarine fissure in the occipital lobe. Neurons in V1 fire action potentials when visual stimuli appear in their receptive field.
Secondary Visual Cortex (V2)
Second major area within the visual cortex, and first region within the visual association area. V2 receives strong feedforward connections from V1 and sends strong connections to V3, V4, and V5, with strong feedback connections to V1.
V2 is tuned to the same simple properties as V1, including orientation, spatial frequency, and color, but also more complex properties like the orientation of illusory contours, binocular disparity, and figure/ground.
V5
Motion-sensitive module of visual system
Dorsal and Ventral Stream
Ventral — “what” pathway, object recognition, memory dependent
Dorsal — “where” pathway, navigation, not memory dependent