Also, the left hemisphere mostly processes sign language. The parts of the brain that are involved in understanding meaning and syntax are largely overlapping, so if deaf people have a sign language, like American Sign Language, then much of the process is the same. Of course, the process of actually receiving the signal for sounds is different. In sign language, the visual cortex does most of the work, whereas in speech it’s mostly the auditory cortex.
BW: How do you study language in people who have had brain damage?
SP: First, you analyze their spontaneous speech as one does with children; that is, transcribe their efforts to speak. Give them challenging sentences to act out or point to on a picture — this will help unravel what they are still able to do. For example, if you give someone a sentence in a passive voice like “The dog was chased by the cat” — which you normally wouldn’t understand just by paying attention to the order of the words. If you did, you would think that the dog was doing the chasing when, in fact, the dog was being chased — and they pointed to a picture with the dog doing the chasing, you know that they are understanding the meaning of individual words, but they’ve lost the ability to analyze them grammatically. Analyzing sentences grammatically is what is necessary in order to understand any kind of complicated language. There are many techniques currently employed.
BW: Computational theory suggests that thinking is a type of computing. How does that apply to language?
SP: I would say that, to understand how we speak, we have to understand the information-processing steps that go from a representation of sound to a representation of meaning. We have to break down the process into subroutines such as extracting and looking at the words, putting them into phrases, figuring out the relationships among them, and matching them to representations in our long-term memory. Each of these requires a different computational step because they have to be understood in both what they are in isolation and how they interact. I think language is endlessly fascinating. I am so fascinated, in fact, that I haven’t been able to cover its interesting aspects and put them into a single book, which is why there are several books on language. My next book is on writing style — how to write better based on what we know about the science of language.
BW: Why did you write “The Better Angels of Our Nature: Why Violence Has Declined”?
SP: I am interested in all aspects of human nature. In addition to my books on language, I’ve written books on the human mind and human nature, including how the brain works, in “The Blank Slate.” The very notion of human nature is suspect to some people. They think that it’s fatalistic or depressing or because, if humans have nature — that is, evolution gave us certain emotions and certain ways of thinking — people worry that this means there’s no possibility of ever changing our society for the better.
I’ve always thought that was a mistake, and, even though human nature does include some nasty components like revenge, greed, and lust, it is also very complex and includes many faculties that could control the uglier parts of human nature. Historical data suggest that we are becoming more peaceful as a species, that the types of violence that were once kept popular for millennia — like dueling, human sacrifice, or slavery — have been abolished. They are proof that human nature could accommodate changes. So, both of those considerations led me to “Better Angels.”
BW: Are we inclined to assume the worst about humanity because of the media?
SP: Yes, that’s right. I think cognitive psychology could explain why we are so misled. Daniel Kahneman and Amos Tversky have put forth that the human mind estimates probability by remembering vivid examples. Because we naturally don’t do statistics, we remember a shark attack and think it’s dangerous to go in the water. We read about a terrorist attack and think it’s dangerous to fly. What we don’t do is calculate the vivid number of violent incidents as a portion of the opportunities for violent incidents to occur. We don’t look at the common denominator when we estimate risk. Now, because news is about things that happen and not about news that doesn’t happen, we hear about every killing spree, every war, and every terrorist attack. We don’t hear about the part of the world where nothing happens, and it does not penetrate our consciousness. Therefore, we overestimate how dangerous the world really is.
BW: Since new information creates new neural connections in the brain, is it correct to assume that the more negative information we gather, the more pessimistic we become?
SP: Yes, I believe that’s true. I believe that when you base your picture of the world on the news, there is a bias toward pessimism. Looking at surveys and gathered statistical information, one can get an accurate and more optimistic view of the state of the world. I think we would be getting a more accurate picture.
This article was originally published in the Spring 2014 issue of Brain World Magazine.
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