Language and the brain

Insights from Neurolinguistics

Brain and spinal cord constitute the central nervous system (CNS)◦ Purpose: Communication

Cellular unit of the nervous system: neurons◦ CNS consists of about 12 billion neurons.◦ Brain consists of about 10 billion neurons.

Brain stem is the control system◦ Regulates breathing, muscle movement, sleep,

body temperature etc.

Basic concepts of Neurology

Modularity and Localization

Phrenology (Gall, 1796)

Basic concepts of Neurology Brain consists of two

hemispheres◦ Right side controls left body

side and vice versa◦ Dichotic listening tests

Hemispheres are connected through Corpus callosum

Language is a left hemisphere phenomenon

Paul Broca (French surgeon and anatomist)◦ Research on brain damage◦ Broca’s area◦ Broca’s aphasia

Carl Wernicke (German physician)◦ Confirmed theory of left hemisphere◦ Wernicke’s area◦ Wernicke’s aphasia

Pioneers of Neurolinguistics

Aphasia and locality

What language impairments are found in Broca's aphasia?

Nonfluent, labored, and hesitant speech absence of function words and inflectional

morphology, short utterances, relatively intact comprehension, awareness of deficit.

Broca’s aphasia

The language symptoms of Wernicke's aphasia are complementary to those of Broca's aphasia.

fluent but empty speech, grammatical inflections, normal

prosody utterances of normal length poor comprehension unaware of deficit.

Wernicke's Aphasia

Goodglass, H., & Kaplan, E. (1983). Boston Diagnostic Aphasia Examination. (2nd ed.). Media, PA: Williams & Wilkins.

“Cookie jar…fall over…chair…water…empty…ov…ov…[Examiner: “overflow?”] Yeah.”

BROCA’S APHASIA

Heny, Jeannine. “Brain and Language (Clark, 634-657).

Well, this is…mother is away here workingout o’here to get her better, but when she’s working, the two boys looking in the other part. One their small tile into her time here. She’s working another time because she’s getting, too.”

WERNICKE’S APHASIA

Heny, Jeannine. “Brain and Language (Clark, 634-657).

Young man, both spoken and sign language:◦ Accident and damage to brain◦ Both spoken and sign languages are affected

Deaf-mute person, sign language:◦ Stroke and damage to left-side of the brain◦ Impairment in sign language

Signer Aphasia

Language learning and brain development go hand in hand.

Children need to be exposed to language early.

Brain is resilient: Early damage can cause right hemisphere

to take over language control.

Language and brain development

Explain how Genie’s language development fits into the theories of Lenneberg, Chomsky and brain development.

According to this text, what is the strongest evidence supporting the theory of a “critical period” for language acquisition?

Was Genie’s early language deprivation the ONLY factor that contributed to her abnormal language development? Explain what other factor(s) might have been involved.

The critical period hypothesis