The genesis of our proposed project lies in the confluence of two significant and perfectly complementary needs, one scientific and the other humanitarian. The scientific need: A fundamental challenge in neuroscience is to understand how we learn to perceive objects in the environment, and the concomitant changes in brain organization. Some questions related to this process can be addressed by studying visual development in infants. However, infants'high distractibility and limited response repertoire constrain the scope of feasible experiments. Furthermore, questions related to the influence of extended deprivation on subsequent learning simply cannot be explored with normally developing infants. An alternative approach is to initiate sight in children who have been allowed to remain blind for several years after birth, even though their blindness is treatable. Clearly, ethical considerations rule out deliberate deprivation as an experimental manipulation. There are very few such naturally occurring cases in the United States since curably blind infants are treated soon after birth. However, a pressing humanitarian need in India offers us the opportunity to adopt this approach while also improving the lives of many children. The humanitarian need: India shoulders the world's greatest burden of childhood blindness. It is estimated that nearly one million children in the country are either blind or severely visually impaired. Over 90% of these children are unable to obtain an education and fewer than 50% survive to adulthood. In over half of the cases, the blindness is treatable or preventable. Most children, however, never receive medical care because the treatment facilities are concentrated in major cities, while over 70% of the population lives in villages. These circumstances effectively ensure that a blind child in a rural family will live a dark and tragically short life. This humanitarian crisis needs to be urgently addressed by providing treatment to curably blind children. The scientific and humanitarian needs described above are mutually complementary;one provides the answer for the other. Our project builds upon this synergy. We propose to initiate and expand outreach initiatives in a partner eye-hospital in India to identify and treat congenitally blind children. Following sight onset, we shall longitudinally study the development of visual object perception abilities in the treated children with the aid of a battery of behavioral tests. Additionally, using functional brain imaging, we shall examine changes in cortical organization as a function of time post-treatment. The behavioral and imaging data together will provide a unique window into the time-course and neural correlates of visual learning. They will also allow us to infer how the mechanisms of learning are influenced by visual deprivation during early, perhaps 'critical', periods in the life-span. We call this project 'Prakash', after the Sanskrit word for 'light', symbolizing the infusion of light in the lives of blind children also the illumination of several fundamental questions in neuroscience.
The WHO estimates that the number of blind children globally increases by 500,000 every year, and although advances have been made in pediatric eye-care to restore sight in a significant proportion of the afflicted children, we have little experimental data about how well the brain can recover visual function following extended blindness. Determining which skills the children are impaired at is crucial for creating effective rehabilitation schemes that would allow the children to be integrated into mainstream society and lead a normal active life;only by having such knowledge would childhood blindness treatment programs globally be fully effective. Not only would Project Prakash directly improve the lives of blind children by providing them treatment, the data on visual learning it generates will help guide the design of effective rehabilitation procedures.
|Gandhi, Tapan; Kalia, Amy; Ganesh, Suma et al. (2015) Immediate susceptibility to visual illusions after sight onset. Curr Biol 25:R358-9|
|Ganesh, Suma; Arora, Priyanka; Sethi, Sumita et al. (2014) Results of late surgical intervention in children with early-onset bilateral cataracts. Br J Ophthalmol 98:1424-8|
|Gandhi, Tapan K; Ganesh, Suma; Sinha, Pawan (2014) Improvement in spatial imagery following sight onset late in childhood. Psychol Sci 25:693-701|
|Kalia, Amy; Lesmes, Luis Andres; Dorr, Michael et al. (2014) Development of pattern vision following early and extended blindness. Proc Natl Acad Sci U S A 111:2035-9|
|Sinha, Pawan; Chatterjee, Garga; Gandhi, Tapan et al. (2013) Restoring vision through "Project Prakash": the opportunities for merging science and service. PLoS Biol 11:e1001741|
|Sinha, Pawan; Meng, Ming (2012) Superimposed hemifields in primary visual cortex of achiasmic individuals. Neuron 75:353-5|
|Sinha, Pawan; Russell, Richard (2011) A perceptually based comparison of image similarity metrics. Perception 40:1269-81|
|Moulson, Margaret C; Balas, Benjamin; Nelson, Charles et al. (2011) EEG correlates of categorical and graded face perception. Neuropsychologia 49:3847-53|