UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
How it Works
Ask a Question
Search Topics
Our Scientists
Science Links
Contact Information
Can blind people who have never seen before dream color?
Question Date: 2004-12-10
Answer 1:

You pose a very interesting question which gets at the heart of Cognitive Science, which is the field interested in studying intelligence from the perspectives of neuroscience, psychology, and computer science, to name just a few fields.

Perception is very much a result of what we experience and how we report it. Perception of color depends on what kind of blindness a person has. In general, I think it might not be possible for a blind person to experience color. However,the brain is very plastic (able to change) so with the proper stimulation it might be able to perceive something to the effect of color.

For the most part, normal vision people experience color due to the receptors in the retina (your eye ball). There are photoreceptors called cones (think cones with a C and color with a C and you'll always remember this). However, what you report as "green" might be experienced differently by you than it is by me.

A philosopher by the name of John Locke wrote about this when he spoke about the Inverted Spectrum problem. You should consider doing a biography on him for a class project.

Your question asks about people who are congenitally blind, that is they have not seen since they were born. There are different kinds of blindness. One kind is where the retina is damaged, in which case the receptors are damaged. Another case is where the optic nerve, which sends information from the receptors to the brain, gets severed.

An eye ball, which contains the retina, is connected to the brain by a wire, the optic nerve. If this nerve is cut, then the information from the eye will not get to the brain, which is the amazing organ which allows us to see. Another sort of blindness is cortical blindness, when the brain area dedicated to vision (which is called area V1) is damaged. It is named V1 because V is for vision and one (1) is for its importance for primary vision. Area V4 is responsible for responding to color.

People who are cortically blind still have the same receptors on the retina as normal vision people. Although they cannot report being consciously able to see,they are able to process things unconsciously. For example, they can see a dot flashed very quickly (evidenced by them pointing to it and catch a ball thrown at them.

You might also want to do a report on a phenomena called synesthesia, which is the ability to taste a color. I don't mean chewing on crayons! People with synesthesia are able to get multisensory stimulation form seeing colors. Blind people might experience this due to the brain's plasticity.

Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2020 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use