Neurolinguistics

Neurolinguistics Lise Menn  What Is Neurolinguistics About? Where in your brain is a word that you've learned? If you know two languages, languages, are they stored in two different parts of your brain? Is the left side of your brain really the language side? If you lose the ability to talk because of a stroke, can you learn to talk again? Do peop people le who who read read lang langua uage ges s writ writte ten n from from left left to righ right t (lik (like e Engl Englis ish) h) thin think k differently differently from people who read languages written from right to left (like Hebrew and Arabic)? What about if you read a language that is written using some other kind of symbols, like Chinese or Japanese? If you're dyslexic, is your brain different from the brain of someone who has no trouble reading? All of these questions and more are what neurolinguistics is about. Techniques like Functional Magnetic Resonance Imaging (FMRI) and event-related potential (ERP) are used to study language in the brain, and they are constantly being improved. We can see finer and finer details of the brain's constantly changing blood flow—where the blood flows fastest, the brain is most active. We can see more and more accurate traces of our electrical brain waves and understand more about how they reflect our responses to statemen statements ts that are true or false, false, ungramma ungrammatica tical l or nonsense nonsense, , and how the brain's brain's electrical activity varies depending on whether we are listening to nouns or verbs, words about colors, or words about numbers. New information about neurolinguistics is regularly covered in national news sources.

 Where Is Language in the Brain? Brain activity is like the activity of a huge city. A city is organized organized so that people who live in it can get what they need to live on, but you can't say that a complex activ activity ity, , like like manuf manufac actur turing ing a produ product ct, , is 'in' 'in' one plac place. e. Raw mater material ials s have have to arri arrive ve, , subc subcon ontr trac acto tors rs are are need needed ed, , the the prod produc uct t must must be ship shippe ped d out out in vari variou ous s directions. directions. It's the same with our brains. We can't say that all of language language is 'in' a particular part of the brain; it's not even true that a particular word is 'in' just one spot in a person's brain. But we can say that listening, understanding, talking, and reading each involve activities in certain parts of the brain much more than other parts. Most of these parts are in the left side of your brain, the left hemisphere, regardless of what language you read and how it is written. We know this because aphasia (language loss due to brain damage) is almost always due to left hemisphere hemisphere injury in people who speak speak and and read read Hebr Hebrew, ew, Engli English, sh, Chine Chinese, se, or Japan Japanese ese, , and also also in peopl people e who who are illiterate. But areas in the right side are essential for communicating effectively and for understanding the point of what people are saying. If you are bilingual, your right hemisphere may be somewhat more involved in your second language than it is in your first language. Are All Human Brains Organized in the Same Way? The organization of your brain is similar to other peoples' because we almost all move, hear, see, and so on in essentially the same way. But our individual experiences and training also affect the organization of our brains—for example, deaf people understand sign language using just about the same parts of their brains that hearing people do for spoken language.

 Aphasia and Dyslexia What is aphasia like? Is losing language the reverse of learning it? People who have lost some or most of their language because of brain damage are not like children. Using language involves many kinds of knowledge and skill; some can be badly damaged while others remain in fair condition. People with aphasia have different different combinations

of things they can still do in an adult-like way plus things that they now do clumsily or not at all. Therapy can help them to regain lost skills and make the best use of remaining abilities. Adults who have had brain damage and become aphasic recover more slowly than children who have had the same kind of damage, but they continue to improve over decades if they have good language stimulation. What about dyslexia, and children who have trouble learning to talk even though they can hear hear norma normally lly? ? There There proba probabl bly y are brain brain diffe differe rence nces s that that acco account unt for for their their difficulties, and research in this area is moving rapidly. Since brains can change with training much more than we used to think, there is renewed hope for effective therapy for people with disorders of reading and language.