The Brain and Blindness

by Jim VanZile

Changes to the Brain

A person may lose their sight and considered themselves blind. Their brain will adapt to the condition and focus on the different senses. This re-organization neurological fucntions of the brain will focus on the other senses will change the brain’s structure. It is generally thought that the brain is hardwired when processing sensory input (Collington, Voss, Lassonde, & Lepore, 2009). This has been found not to be the case. The brain is able to restructure itself and the other senses will become more pronounced.

What happens to my brain when I lose my sight?

Different areas of the brain will begin to become more active and larger depending on what sense is being utilized the most to accommodate for the loss of vision. Collington and his team explain that hearing is often the first sense to help compensate for the loss of vision. The research showed that people that were blind used more of the occipital cortex of the brain. This over use would change the brain structure in this area and it would be larger than a person who was not blind. The brain will almost immediately begin compensating for the loss of vision by strengthening other senses (Boldt, Seppa, Malinen, Tikka, & Hari, 2014). Boldt and his team are not suggesting the changes will be immediately noticed but explain that the brain begins the process to adapt to the loss of vision.

Does when I lose my sight effect how much my brain will change?

The age when a person becomes blind also effects the changes to the brain. The earlier a person becomes blind the more change to the brain will occur (Collington et al., 2009). Collington and his team explain that change will occur even when a person becomes blind later in life. The change may not be as pronounced and the plasticity of the brain may limit the amount of reorganization of the brain. The plasticity of the younger brain will make it easier to adjust and adapt to change (Boldt, Seppa, Malinen, Tikka, & Hari, 2014).


It has been shown that early blind patients do better at auditory tasks than sighted subjects (Boldt, Seppa, Malinen, Tikka, & Hari, 2014). Boldt and his team found that the younger the subjects were the better the results they received concerning auditory spatial variability. Their results also indicated that the brain did continue to re-organize itself in the subjects that loss their vision later in life. The changes were still signifigant and better than someone with their vision.


The photographs show how the different areas of the brain are effected by the loss of vision. The earlier the loss of vision occurs the more pronounced and active temporal lobes become.

Useful Articles Concerning the Brain the Loss of Vision

These three articles provide more information concerning the changes to the brain when the loss of vision has occurred.


Cross-modal plasticity for the spatial processing of sounds in visually deprived subjects:


http://dx.doi.org/10.1007/s00221-008-1553-z


Blindness causes structural brain changes, implying brain can re-organize itself to adapt


http://www.sciencedaily.com/releases/2009/11/091118143259.htm


Spatial variability of functional brain networks in early-blind and sighted subjects


http://dx.doi.org/http://dx.doi.org/10.1016/j.neuroimage.2014.03.058

Informational Videos Concerning the Brain and the Loss of Vision

Dr. Brian Wandell discusses a subject that lost his sight and the effects it had on his brain. The subject was able to obtain the world record for blind downhill skiing. There are some good illustrations in the video and point out how the loss of vision effects the brain.


https://www.youtube.com/watch?v=VVgfC_FV2hI


Dr. Eric Kandel discusses the effects of blindness and describes how vision, loss of vision, and hearing all work in the brain. The video contains good illustrations which are easy to understand.


http://www.bloomberg.com/news/videos/b/358f1134-9560-4888-940e-1a3a987a3417

References

Boldt, R., Seppa, M., Malinen, S., Tikka, P., & Hari, R. (2014). Spatial variability of functional brain networks in early-blind and sighted subjects. NeuroImage, 95(1), 208-216. http://dx.doi.org/http://dx.doi.org/10.1016/j.neuroimage.2014.03.058


Collington, O., Voss, P., Lassonde, M., & Lepore, F. (2009, January). Cross-modal plasticity for the spatial processing of sounds in visually deprived subjects. Experimental Brain Research, 192(3), 343-358. http://dx.doi.org/http://dx.doi.org/10.1007/s00221-008-1553-z


University of California - Los Angeles (2009, November 19). Blindness causes structural brain changes, implying brain can re-organize itself to adapt. Science Daily. Retrieved from www.sciencedaily.com/releases/2009/11/091118143259.htm