July 19, 2006

Language and Learning

How does language affect the way we think? What does our language and learning do to our brain? This was the topic of Monday's KQED Forum where Michael Krasny interviewed Jerome Feldman about his new book, From Molecule to Metaphor: A Neural Theory of Language. Feldman's book gives a unique insight into the latest understandings on what science tells us about how learning and language shape the brain.

From Molecule to Metaphor

In From Molecule to Metaphor, Jerome Feldman proposes a theory of language and thought that treats language not as an abstract symbol system but as a human biological ability that can be studied as a function of the brain, as vision and motor control are studied. This theory, he writes, is a "bridging theory" that works from extensive knowledge at two ends of a causal chain to explicate the links between. Although the cognitive sciences are revealing much about how our brains produce language and thought, we do not yet know exactly how words are understood or have any methodology for finding out. Feldman develops his theory in computer simulations--formal models that suggest ways that language and thought may be realized in the brain. Combining key findings and theories from biology, computer science, linguistics, and psychology, Feldman synthesizes a theory by exhibiting programs that demonstrate the required behavior while remaining consistent with the findings from all disciplines.

After presenting the essential results on language, learning, neural computation, the biology of neurons and neural circuits, and the mind/brain, Feldman introduces specific demonstrations and formal models of such topics as how children learn their first words, words for abstract and metaphorical concepts, understanding stories, and grammar (including "hot-button" issues surrounding the innateness of human grammar). With this accessible, comprehensive book Feldman offers readers who want to understand how our brains create thought and language a theory of language that is intuitively plausible and also consistent with existing scientific data at all levels.

Just the other day, I mentioned a story on NPR about how bonobos are proving that humans are not the only creatures that can learn and use language to communicate. Looking at Feldman's theory it seems that much of what we know about language makes it not too surprising that our close relatives would have the same capacity, because their wiring would be same.

Here were some notes that I took when listening to the interview. First of all, scientists now believe that we can study the brain and human knowledge in the same way as we study other human biological systems, such as vision. Feldman started by talking about how scientists realized that the human brain isn't really like a computer. As he said, we have incredibly fast reaction times, but the neurons in our brains are slow. So how can we have such fast reactions? It's because the neurons are hardwired. Today, our computer systems are very fast because we've optimized the speed of the components and the networks that connect them. But the human brain reacts very fast despite the slow neurons because there isn't any need to do computation to make a connection as our brains are hardwired. Our brains operate like massively parallel processing systems, whereas our computers are still mostly serialized.

In the brains of very young children every possible path is connected, but as we learn some paths are reinforced and others atrophy or disappear. In very young children, learning is largely chemical and relatively unconnected to their experiences. But as humans grow, learning transforms from being chemical to being based on our experience, both direct (what I experienced) and indirect (what I learned without experiencing).

The first words that young children learn are labels for their experiences. Many of the simple words in English, like hot, hand, hat, etc., are the first words that children learn. Next they acquire language that consists of metaphors: words like beauty, truth, and love. You can understand all these abstract words as something mapped onto direct experience and interpreted by imagination.

What Feldman is describing is a science that is very interdisciplinarian as it combines anthopology, cognitive science, linguistics, and the science of computation. And he believes that as we understand how we learn, we will have more appreciation of how people learn (including ourselves) and what it takes to change and transform what we have already learned.

Because our brains are hardwired, once we've learned something, it is very hard to "unlearn" it or to rewire for a new circumstances. He used the experience of grief as an example of what happens. When someone you love dies, their presence in the wiring in your brain is still there, and so they pop up in all kinds of situations. It takes a while before your brain's wiring can change and come to accept their absence. This insight helps us understand even more why people experience cognitive dissonance before they can finally realize that what they had believed does not reflect reality.

When I attended the Science Caucus at Yearly Kos, one of the participants told us that one thing we've learned about learning is that once humans learn incorrect facts (such as believing that evolution is wrong), it will take rewiring the brain in order to learn that this belief was wrong. So when a child learns that evolution is not real, it will take much more work to undo that faulty fact than it does to learn the facts correctly the first time. This is why for some people it literally takes deprogramming before they can see the world realistically. It also means that we have a lot of work to do to make it possible for children to be exposed to experiences and knowledge that are healthy and realistic - otherwise we continue to have more and more people who are not able to deal adequately with reality.

Posted by Mary at July 19, 2006 12:08 PM | Science | Technorati links |

"...one thing we've learned about learning is that once humans learn incorrect facts (such as believing that evolution is wrong), it will take rewiring the brain in order to learn that this belief was wrong."

I once was talking with a coworker about the OJ Simpson case, when he said something about that indicated he didn't understand how people of different races could marry. So I explained to him the scientific definition of species, using the horse and donkey as an example of two animals not in the same species; of course, humans are all one species. I could see the wheels turning in his head as he unlearned a lifetime of racism.

You can't look at knowledge as a homogenious "thing." It is structured, and changing a root piece of knowledge can "automatically" rearrange a large amount of learning. This is why people "convert".

Teaching creationism is a bad idea, but it is not so bad if "seeking truth" is also taught as a value, because seeking truth will lead people to a more nuanced view of the matter, and even to conversion. Teaching "avoiding truth" is much worse than any disprovable dogma.

Posted by: Chris Vail at July 19, 2006 11:22 PM