Someone Natively Blind Can Now See?

[david_myers]

Originally posted on April 28, 2014.

Reports of restored vision in children in India have been confirmed in a new Psychology Science article, summarized here, on “Improvement in spatial imagery following sight onset late in childhood.”

The research, led by Tapan Kumar Gandhi of MIT’s Brain and Cognitive Sciences department, in collaboration with Suma Ganesh and Pawan Sinha, studied children who were blinded from birth by dense cataracts. After surgery removed the cataracts at about 12 to 14 years, the children were no longer completely blind. Their abilities to discern light and dark, enabled some spatial imagery.

Practically, I wondered, what does this mean? Doesn’t the brain need to experience normal sensory input early in life in order to produce normal perceptual experience later in life? I asked Dr. Gandhi to explain the children’s post-surgery abilities. Could they potentially ride a bicycle or drive a car? His answer (quoted with permission):

The onset of sight is not immediately accompanied by much joy or pleasure, contrary to what is depicted in movies. The child has to get used to the new inputs. Over the first few weeks, the child begins to feel more comfortable with the visual world, even though they might not recognize much of it. Their visual acuity is sub-par, most likely permanently so. But, despite a blurry percept, the brain is able to achieve significant proficiency over the course of the first half year on many visual skills such as face detection, and visually guided navigation. Although driving is well-beyond their economic means, some of the Prakash children have indeed learned to ride a bicycle. We typically find that the children and their parents are in high spirits when they visit us for a clinical follow-up a few weeks after the surgery.