A researcher at Princeton has made a major discovery about how the brain works, and his findings may have major implications for autism research. The research has to do with the cerebellum, the part of the brain that coordinates movement.
Sam Wang, a neuroscientist, will give a talk on his work as part of the Princeton Plasma Physics Laboratory’s Science on Saturdays program on Saturday, March 3, from 9:30 to 11 a.m. at 100 Stellerator Road, Princeton. The talk was rescheduled from February 17.
“The big question that we’re trying to answer is about how the brain learns from experience in early childhood,” Wang says. “Brains come with a genetic program. They come unformed, but they come with programming that gets them ready to learn from the world around them. They are not blank slates. They are learning machines.”
For the past 10 years Wang has been probing exactly how these learning machines operate. Much of his research involves mice, which are often used by neuroscientists as a model for studying brain structure and function.
From the moment they are born, babies learn at an incredible rate. Very quickly, they learn to associate a face with a voice and to appreciate symmetry in faces, and they must be incredibly flexible. “Babies have to be ready for any environment they might encounter,” Wang says. “It could be a different language, a different environment, and in some cases they might not have very good hearing or vision. They have to be adaptable.”
From ages 0 to 6, humans go through an incredible period of learning about the world through experience. Autism is one way that this process can go awry.
Wang’s research could shed light on a disorder whose origins remain shrouded despite decades of research. “The one thing we know more than anything else is that autism has deep genetic roots,” he says. “That is the most rock solid fact we know about autism.” But how exactly do the genetic factors interact with the development of the brain to create autism?
Wang’s new research begins to answer this long-standing question, and it involves the cerebellum.
In adults the cerebellum — a part of the brain at the back of the skull — coordinates movement. It is also involved in making split-second predictions about what will happen next in the world, an ability that is crucial to coordination. For example, the cerebellum is what anticipates simple things such as when your foot will hit the ground when walking.
“The cerebellum seems to be important in making predictions about the world and telling you when something surprising has happened and reacting to it,” Wang says. “We are testing the idea that what the cerebellum does for moving in adults, it may also do for sorting out surprising and un-surprising situations for infants.”
Wang believes that as the cerebellum reacts to the world and makes predictions, it helps guide the development of the brain as a whole. If that’s true, it could answer many questions about how autism develops.
“It’s a big surprise that the cerebellum guides cognitive development during early life,” Wang says. He believes the insights he has gained into how experience teaches the brain could be a “game changer.”
“There are weird mysteries in the field that have yet to be connected up,” Wang says. For example, babies who go on to be diagnosed with autism often show early motor problems, but no one knows why. If Wang is correct, and the cerebellum is involved, this would make perfect sense.
The question of autism research is not the old nature versus nurture debate — whether the disorder is driven by genes or by the environment — but how the genes drive changes in development as the brain forms in response to the environment. Wang’s research points to genetics causing changes in the cerebellum, which knocks overall cognitive development off track.
“This dance between genes and experience means both are important,” he says. “Genes set the stage, and then experience is what acts upon that stage to help the brain develop.”
Wang has yet to reveal details about the experiments he conducted and how he reached these conclusions. However, he says he will discuss this in detail at his lecture. He has also submitted a paper to a major science journal, which he expects to be published in the near future.
Wang does say that the research would not have been possible if not for recent advances in the tools used to study the brain. Traditionally, efforts at brain mapping at the individual neuron level have relied on electrodes or labeling neurons with chemical or genetic markers. But recently developed optical techniques can image the activity of single neurons. This allows researchers like Wang to study the brain in greater detail than ever before.
“I’m excited about the work my lab is doing,” he says. “We are using technology in a way where someone with my skills, which are based in physics; and technology developments in a way that can make contributions to understanding the brain.”