Editing Blindsight (section)

== Describing blindsight ==
Patients with blindsight have damage to the system that produces visual perception (the [[visual cortex]] of the brain and some of the [[nerve fibers]] that bring information to it from the [[eyes]]) rather than to the underlying brain system controlling eye movements.<ref name="Carlson 2013 4"/> The phenomenon was originally thought to show how, after the more complex perception system is damaged, people can use the underlying control system to guide hand movements towards an object even though they cannot see what they are reaching for.<ref name="Carlson 2013 4"/> Hence, visual information can control behavior without producing a [[conscious]] sensation. This ability of those with blindsight to act as if able to see objects that they are unconscious of suggested that consciousness is not a general property of all parts of the brain, but is produced by specialized parts of it.<ref name="Carlson 2013 4"/>

Blindsight patients show awareness of single visual features, such as edges and motion, but cannot gain a holistic visual percept. This suggests that perceptual awareness is [[Modularity|modular]] and that—in sighted individuals—there is a "binding process that unifies all information into a whole percept", which is interrupted in patients with such conditions as blindsight and [[visual agnosia]].<ref name="Visual perception and awareness" /> Therefore, object identification and object recognition are thought to be separate processes and occur in different areas of the brain, working independently from one another. The modular theory of object perception and integration would account for the "hidden perception" experienced in blindsight patients. Research has shown that visual stimuli with the single visual features of sharp borders, sharp onset/offset times,<ref>{{cite journal|vauthors = Alexander I, Cowey A|title = Edges, colour and awareness in blindsight|journal = Consciousness and Cognition|volume = 19|issue = 2|pages = 520–33|date = June 2010|pmid = 20171122|doi = 10.1016/j.concog.2010.01.008|s2cid = 36139700}}</ref> motion<ref name=":6">{{cite journal|vauthors = Ffytche DH, Zeki S|title = The primary visual cortex, and feedback to it, are not necessary for conscious vision|journal = Brain|volume = 134|issue = Pt 1|pages = 247–57|date = January 2011|pmid = 21097490|pmc = 3159156|doi = 10.1093/brain/awq305|author2-link = Semir Zeki|doi-access = free}}</ref> and low [[spatial frequency]]<ref>{{cite journal|vauthors = Sahraie A, Hibbard PB, Trevethan CT, Ritchie KL, Weiskrantz L|title = Consciousness of the first order in blindsight|journal = Proceedings of the National Academy of Sciences of the United States of America|volume = 107|issue = 49|pages = 21217–22|date = December 2010|pmid = 21078979|pmc = 3000284|doi = 10.1073/pnas.1015652107|bibcode = 2010PNAS..10721217S|doi-access = free}}</ref> contribute to, but are not strictly necessary for, an object's salience in blindsight.