The phenomenon in which people with damage to the primary visual cortex (V1) are unable to consciously perceive visual stimuli but still have the ability to respond to visual information occurs despite the fact that the person is functionally blind in the affected area of the visual field. People with a blind site can perform tasks such as detecting the movement or location of objects, or detecting changes in lighting, although they are not aware of these stimuli. It is thought to be related to the activity of other visual pathways, such as the upper mound, which can process visual information outside of conscious perception. The blind site is often associated with cortical blindness, which occurs due to damage to the occipital lobe, and emphasizes the distinction between conscious perception and unconscious visual processing.