Blindness & Brain Structure
Why is brain structure different in the blind?
The Visual Cortex and Changes in Brain Structure.
In the blind, this area of the brain is not stimulated by images from the eyes, as the eyes cannot see. It is stimulated instead, by other senses (touch and hearing) used by the blind to judge their surroundings. The normal areas for these senses also have grown to compensate for the lost sense of sight (University of California, 2009). It reorganizes itself to accommodate for the loss of a sense (University of California, 2009). Amazing!
Studies show an enlargement of the core areas of the auditory cortex and other studies show an increase in size of the "planum temporale (an area behind the auditory cortex important in language and music processing) in blind musicians with absolute pitch than those sighted with the same skill" (Hirsch, Bauer, & Merabet, 2015, p. 4).
It is believed that the structural changes that occur in those who are blind is due to the increased reliance on non-visual senses and as a result, "this structural plasticity appears to be associated with non-visual sensory skills within the context of behavioral
compensations" (Hirsch, Bauer, & Mirabet, 2015, p. 5).
Does it matter at what age a person goes blind for changes to occur?
The blind can see?
Technological Advancements Helping the Blind Actually "See"
"The experimental device is made by a company called Second Sight in Santa Clarita, California. It now consists of miniature camera attached to a pair of glasses that sensds a signal to a wireless receiver planted behind the patient's ear. The signal then goes through a tiny wire implanted under the skin, into the eye to an electronic chip attached to the retina itself" (Hreff, 2015, para. 5). If you would like to read more about how the bionic eye glasses work please click the link below.
Educational video on the vision system. (2009). Diopsys. Retrieved from www.youtube.com.
Hirsch, G. V., Bauer, C. M., & Merabet, L. B. (2015). Using structural and functional brain imaging to uncover how the brain adapts to blindness. Annals of Neuroscience and Psychology, 2(5), 1-11. Retrieved from http://www.researchgate.net/publication/281716740_Using_structural_and_functional_brain_imaging_to_uncover_how_the_brain_adapts_to_blindness.
Hreff, Z. (2015). Eye camera may help the blind see. ABC News. Retrieved from http://abcnews.go.com/Technology/CuttingEdge/story?id=97825&page=1.
Kish, D. (2015). How I use sonar to navigate the world. Ted. Retrieved from http://www.ted.com/talks/daniel_kish_how_i_use_sonar_to_navigate_the_world#t-22964.
University of California.(2009). Blindness causes structural brain changes, implying brain can re-organize itself to adapt. ScienceDaily. Retrieved from www.sciencedaily.com/releases/2009/11/091118143259.htm.
Sanford, K. (2015). Can we restore sight for the blind? [video] DNews. Retrieved from www.youtube.com.
Wandell, B. (2009). Understanding blindness and the brain. [video] Stanford University. Retrieved from www.youtube.com.