LANGUAGE AND YOUR BRAIN
For decades research into the brain basis of language was limited to the study of the effects of neurological disease and brain lesions on human language processing and production. Nowadays, however, new techniques are allowing
researchers to create a picture of a normal twain at work processing language — helping lo shed light on the mysteries of language and the brain.
Associated with motor planning and speech production, Broca's area is believed to be responsible for lexical and phonological processing. Patients who suffer damage to this part of the brain — a disorder known as Broca's aphasia —
have difficulty speaking but can I still understand language.
Considered the area of the brain critical for language comprehension. Wernicke's area is responsible for processing speech sounds. Patients with lesions to this part of the brain suffer speech comprehension problems and. although
capable of producing sounds and word sequences at a normal rhythm, are unable to produce meaningful speech.
The vocalization region of the motor cortex controls the mouth and lips, involved in the physical production I of speech.
Receives signals from the auditory nerves in the inner ear and transmits temporal and spatial frames of reference for the data it receives.
a-pha-sia [uh-fey-zhuh] (noun) - the loss of a previously held ability' to speak or understand spoken or written language, due to disease or injury of the brain.
Example of brocas aphasic speech
Cindcrella...poor...um ’dopted her...scrubbed floor, um, tidy.-.poor, um...’dopted...Si-sisters and mother...ball. Ball, prince um, shoe...
Example of Wernicke’s aphasic speech
Uh, well this is the... the /dodu/ of this. This and this and this and this. These things going in there like that. This is /sen/ things here. This one here, these two things here. And the other one here, back in this one, this one /gesh/ look at
COMMON BRAIN IMAGING TECHNIQUES
MRI FUNCTIONAL MAGENTIC RESONANCE IMAGING
An MRI machine uses a magnetic field and radio the brain and detect brain activity. These changes in blood flow, which arc captured on a computer, help researchers understand more about the role of specific structures in the brain.
Advantages: Good spatial resolution; non-invasive
Disadvantages: poor temporarily resolution; expensive; for patients with metallic devices (e.g pacemakers)
One of the first way's of non-invasively observing brain activity, EEG uses electrodes attached to the scalp to record the electrical activity of neurons in the brain. This method can be used with subjects w ho an- awake, asleep or
Advantages: Excellent temporal resolution; relatively inexpensive;
Using magnetic coils placed over a subject's head and hyper, sensitive magnetometers called SQUIDs, MEG measures faint magnetic fields produced by electrical activity in the brain.
Advantages: Best temporal resolution; good spatial resolution; non-invasive; complementary to other techniques
Disadvantages: Expensive; neuromagnetic signals are weak and difficult to measure; does not provide structural information.
PET (positron emission tomography)
One of the most popular scanning techniques in neuro-science research, PET allows scientists to observe blood flow and metabolism in the brain. First, the subject is injected with a small dose of radioactive glucose, From outside the
scalp, the PET scanner tracks the metabolism of the radioactive substance.
Advantages: Measures metabolism and provides an image of brain activity
Disadvantages: Expensive; not widely available; radioactive material used
HOW WE LEARN LANGUAGE
In the 1950s, Noam Chomsky posited | that we are born with a language acquisition device (LAD) that gives us the "innate" ability to acquire language. This hypothesis attempted to account for the complexity of language systems,
which allow us to make "infinite use of finite means."
Related to this is Chomsky's theory of Universal Grammar, which suggests that there are grammatical properties common to all human languages. Although humans cannot be hard-wired to learn a particular language, our brains are,
indeed, hard-wired with some of the same rules of grammar.
Although researchers are in perpetual disagreement over the relationship between age and language learning capacity, many studies suggest that Acre's a critical period" after which language learning becomes significantly more difficult.
I the younger a person is exposed 10 a foreign language, the greater the chances are that the person will achieve proficiency in that L2.
One study, "Critical Period Effects In Second Language Learning" (1989) by Jacqueline Johnson and Elissa Newport, which compared English grammar test scores for immigrants based on the age at which they arrived in the United
States, shows that earlier exposure to a language results the greater proficiency'.
In addition to accelerating the rate at which we achieve proficiency, studying a language earlier in life can hare the following benefits:
Increased cognitive skills Fatly experience with two languages, gives children mental flexibility. Superiority in concept, formation, and diverse mental abilities.
Higher achievement in other academic areas Mini-grade student who receive 30 minutes of language lessons each ‘seek typically score higher on academic achievement tests than those without language lesson
Higher standardized test scores A+ Students who studied a foreign language in high school scored higher on the verbal section of the Scholastic Aptitude Test.