NEUROPLASTICITY OF THE BRAIN
Structural changes in the brain of blind individuals
- Sensations from the retina of the eye are converted into electrical impulses
- The electrical impulses conveyed by the optic nerve to the brain.
- In the brain these impulses are processes in the visual cortex to recognize the visual sensations (Grady, 1993).
When does blindness occur?
- Blindness occurs when any parts involved in the visual process is damage
- Most visual loss is caused by eye diseases like glaucoma and cataracts (Thompson, 2016).
Is there a difference between the brain of a person who is blind and one who is not blind?
- In the brain of blind individuals the visual areas of the brain are smaller as compared to those of individuals who are not blind. In the same token the non-visual areas of the blind are larger than in individuals who are not blind (ScienceDaily, 2009). An example is in blind individual the frontal lobes are abnormally enlarged.
Are there other structural changes in the brain of blind individuals?
- Studies have shown that the brain of a blind person undergoes structural changes to accommodate compensation of visual loss with other senses like hearing.
- This is particularly evident in how the brain reorganizes itself through neuroplasticity.
- Through neuroplasticity the functions of visual cortex become intertwined with those of other senses.
- The brain rewires itself to connect the auditory regions of the brain with those of the visual cortex (Fields, 2010).
- Linguistic tasks are carried out by visual cortical activity (Welsh, 2011).
Do these brain structural changes occur in people who were born blind?“It is only in people who lose sight later in life, that the visual connections can be rerouted to process auditory information” (Michelon, 2011, para. 5).
Fields, R. D. (2011). How can some blind people process speech far faster than sighted persons? Retrieved from http://www.scientificamerican.com/article/why-can-some-blind-people-process/
Grady, D. (1993). The vision thing: Mainly in the brain. Retrieved from http://discovermagazine.com/1993/jun/thevisionthingma227
Michelon, P. (2011). How the brain of a blind person rewires itself. Retrieved from http://sharpbrains.com/blog/2011/03/25/how-the-brain-of-a-blind-person-rewires-itself/
ScienceDaily. (2009). Blindness causes structural brain changes, implying brain can re-organize itself to adapt. Retrieved from https://www.sciencedaily.com/releases/2009/11/091118143259.htm
Thompson, D. (2016). What Causes blindness? Retrieved from http://www.everydayhealth.com/vision-center/what-causes-blindness.aspx
Welsh, J. (2011). Trading places: Blind people use visual brain region for language. Retrieved from http://www.livescience.com/13003-blindness-brain-language-110228.html