Seeing Is Researching

By queensland90..^_^

If blind eyes could see. What does that mean?

That's the question neuroscientist Pawan Sinha and his team at MIT has begun to answer in an endeavor, as much humanistic as scientific. They've launched the Prakash Project, named for the Sanskrit word for ‘light,‘ intended, at first, to cure blind children in India. It's a noble effort, given that India has the world's highest population of blind people, less than half of whom survive to their third birthday and less than one percent of whomare employable.

According to Sinha, who presented at the One Mind for Research Forum, his team screened 20,000 blind children and treated 700 of them for problems such as cataracts. These 700 children can now see.

Sort of.

Their vision doesn't arrive, voilà, as with the Biblical character Bartimaeus. Instead, parts of vision develop, gradually. And in surprising ways. Many developmental scientists, including Nobel Laureates, have long asserted that congenitally blind children older than 5 to 10 years of age probably will never see again - surgery or not. That's because sight doesn't just involve the eyes. It also involves the brain.

If the brain loses the opportunity to take in what the eyes are seeing - and subsequently wire and fire up - the brain eventually stops trying and shuts down. The time frame in which this wiring and firing can occur is called a "critical period" of development. It's a window of time.

Researchers had thought the critical window of sight was open only for a limited time. But investigators such as neurobiologist Takao Hensch, at Children's Hospital Boston, have discovered that's not necessarily the case. In mice, he probed the neuro-molecular changes that occur in the brain to open and close the window of sight. He circuits that open the window, guided by an inhibitory neurotransmitter called GABA, and a protein called Lynx1 and special encapsulating cells called perineuronal nets that close it.

Mimicking or re-introducing these chemicals or structural changes might potentially serve to speed the window's opening, delay its closing or simply shift the whole entity backward or forward in time. It's a bit like mind control.

Meanwhile, the Indian children given "sight" are also offering eye-catching findings. Even though the recognized developmental window for vision has closed, some aspects of their vision still develop. Whats so cool about this is that unlike in babies who are developing vision, older children can actually talk about what they are experiencing allowing researchers to open their own window to the brain.

In a fascinating series of visual tests shown midway through this video clip, Sinha's team dissects out exactly what is wheat and what is chaff.

For example, the children retain a latent ability to segment images. This means they can look at a photograph of a person standing in his driveway next to a car and identify the shape that is the person, the one that is the tree and the one that is the car. Even more, Sinha found that this segmenting ability emerges from motion; the researchers move around the parts of the picture around, and only then do the children understand what they are looking at.

In essence, the brain learns to see and recognize objects with the help of movement. Sinha calls this "dynamic information processing," or motion processing.

"Motion information serves as the bedrock for building the rest of the complexity of visual processing," Sinha says.

This simple idea has far reaching implications. Sinha's group is using it as a recipe for constructing machine-based vision systems that can learn on their own. And the team is also applying their findings to autism, in which people have trouble integrating visual cues. This might be a sign of a deficiency in dynamic information processing and the opening of a route to therapy.

Beyond the lab or clinic, Sinha always has his eye on the many more blind children in India who need help. And there are many. Millions.

"It''s been just a phenomenal experience because we have gotten to do interesting research, while at the same time helping the many children that we have worked with," Sinha says.