Summary

The primary visual cortex is an area involved in processing visual stimuli. This brain region receives information from the eyes and transmits this information for further processing.

Function

The primary visual cortex is part of the visual cortex, the brain area required for perceiving visual stimuli. Compared to the rest of the visual cortex, the processing of simple aspects of stimuli within our visual field takes place in this area. The area receives information from the eyes, processes this information, and transmits the result to the other visual areas.

Neurons in this area each respond to input coming from a specific part of the visual field. Stimuli that are close together in the visual field activate neurons that are close together in the primary visual cortex. This creates a map of the visual field in our brain. This organization is called "retinotopy”. In addition, there are more neurons in this area that respond to images that fall on the center of the eye, so the central part of our visual field is processed at 'higher resolution' than the rest. Thus, by focusing our eyes on a particular object, our brains get a better picture of this object.

Location

The primary visual cortex is located in the center of the occipital lobe, in the calcarine sulcus. Synonyms for this area are V1, striate cortex and Brodmann Area 17.

Fact

Neurons in this area respond most strongly to specific orientations. There are cells that respond primarily to horizontal lines, other cells respond most strongly to vertical lines, and still other cells respond strongly to oblique lines.

Patients

When there is severe damage to this area it can lead to 'blindsight'. This is an unusual condition in which people cannot see anything in part of their visual field but can still process information. When presented with a picture there, they indicate that they have not seen anything. However, if you ask them to choose from two options, they can still correctly guess what the picture was! In other words, they no longer see consciously, but they still see unconsciously.

Author: Myrthe Princen (translated by Melanie Smekal)

Image: Marcel Loeffen