CHAPTER 9

1. CHAPTER 9 Hearing and Language Language

2. Language • not limited to speech • includes the generation and understanding of • Written • Spoken • gestural communication. • Is this just a human behavior? • Expressivevs.receptive language: • Expressive: spoken, written produced language • Receptive:

3. Language aphasias • Aphasia: • In 1861: French physician Paul Broca first reported aphasia – • language impairment caused by damage to brain • results from damage to the frontal area anterior to the motor cortex, now known as Broca’s area. • Broca’s aphasia: • language impairment caused by damage to Broca’s area and surrounding cortical and subcortical areas. • It is also referred to as expressiveaphasia. • http://www.youtube.com/watch?v=1aplTvEQ6ew • http://www.youtube.com/watch?v=tYmm23EPXjU&feature=related

4. Receptive Language • Nine years later: German doctor: Carl Wernicke identified a second critical language site: Wernicke’s area • damage produced a different form of aphasia- more with “understanding” • located in the posterior portion of the left temporal lobe, now known as Wernicke’s area. • Wernicke’s aphasia: • the person has difficulty understanding and producing spoken and written language. • Often called receptive aphasia • term is misleading: Same problems with understanding language also show up when producing it. • If can’t understand, then can’t produce! • http://www.youtube.com/watch?v=gKWEAgnuE1M

5. Dyslexia, Alexia and Agraphia: • Alexia: inability to read. • Agraphia: inability to write. • Presumably due to disruption of pathways in the angular gyrus • Connect visual projection area with auditory and visual association areas • Critical areas in temporal and parietal lobes. • Results in inability to integrate two activities

6. Dyslexia, Alexia and Agraphia: • Dyslexia: learning disorder • impairment of reading • Dysgraphia: difficulty in writing • Dyscalculia: disability with arithmetic. • Dyslexia can be acquired, but it is more often developmental. • In most people the planumtemporale, where Wernicke’s area is located, is larger in the left than in the right. • However, in dyslexics, it is more frequently equal in size or larger on the right. • Also: may be due to problems inbasal ganglia and cerebellum • Problem with inhibiting inappropriate behaviors while engaging in academic behavior • Can’t walk and chew gum and read at same time!

8. How Diagnosis Language Disorders? • Rasmussen and Milner (1977) used Wada technique • involves anesthetizing one hemisphere at a time by injecting a drug into each carotid artery; • when the injection is into the language-dominant hemisphere, language is impaired. • Risky to say the least! • Also used electrical stimulation • Determined location of language control in patients before removing lesioned tissue that was causing epileptic seizures.

9. Right Hemisphere and Language • The right hemisphere: • Important in understanding information from language that NOT specifically communicated by word meaning • Critical for determing information when meaning must be inferred from entire discourse • when the meaning is figurative rather than literal. • Think of idioms; sarcasm, intonation and inflection • Very difficult: must compare words to tone • Often lacking in autism spectrum individuals

10. Right Hemisphere and Language • Prosody: important right hemisphere language function! • use of intonation, emphasis and rhythm to convey meaning in speech. • Most obvious right-hemisphere role in language • Often show difficulty after a stroke or with disorders such as autism • http://www.youtube.com/watch?v=1Nh2BYvK7_8

11. plasticity • Brain shows incredible plasticity • Right hemisphere can take over language functions following left-hemisphere damage and vice versa • Recovery good as long as the injury occurs early in life • Good results below age 6; okay results pre-puberty • Much more problematic in adults. • http://www.youtube.com/watch?v=rH0TgAZ4coc&feature=related

12. Why Language? • Darwin: • suggested we have an instinctive tendency to speak • What mean? • infants seem very ready to engage in language • Language learning is innate • learn with minimal instruction. • Noam Chomsky (1980) and later Steven Pinker (1994): • interpreted children’s readiness to learn language as evidence of a language acquisition device • part of the brain hypothesized to be dedicated to learning and controlling language.

13. Language • Is nurture not important? • Not all researchers agree with innate language theory • E.g., Skinner • Most accept that there are biological reasons why language acquisition is so easy. • Why ease of children’s language acquisition? • due to a brain-based sensitivity to rhythmic language patterns • Sensitivity does not depend of the form of language. • Whatever language you are exposed to, your brain becomes “tuned” to • Think about in terms of cochlear implants!

14. Imitation and Language • Researchers believe that the ability to imitate gestures was critical to the development of language in humans. • Recent evidence: infants who point/gesture learn language faster • Baby sign • Some language theorists may have identified mechanism for the imitative development of language: • mirror neurons • respond both when engage in specific acts and while observing the same act in others. • Critical for matching your behavior to behavior of others

15. Animal Language • Why study Animal language: • intrigues us: We want to know whether we have any company “at the top,” • trace the evolutionary roots of language. • The rationale behind animal language research: • any behavior or brain mechanism we share with genetically related animals must have originated in those common ancestors. • Evidence of language in other animals? • Many animals studied: • dolphins, elephants, whales, and gorillas • major contender for a co-possessor of language has been the chimpanzee because is closest genetically • That not necessarily best organism , however,.

16. Alternative Approach to Language • Examine animal language from their point of view • See if can determine syntax, semantics from recordings of ongoing language • Good evidence for language in several animals • Tamarins • Sea mammals • Elephants • Can determine whether other animals share brain organization associated with human language. • But remember: Presence of similar brain structures in other animals does not mean that they use those structures for language. • Correlation does not equal Causation • Must proceed with caution

17. Studying Animal LanguaGe • Viki: • Early study attempted to teach the home-reared chimpanzee Viki to talk • After six years she learned only “mama,” “papa,” and “cup.” • Later researchers concluded that chimpanzees lack the larynx for forming word sounds • Noted tendency of chimps and gorillas to communicate with a number of gestures, tried teaching American Sign Language. • Over a four-year period the chimpanzee Washoe learned to use 132 signs • Taught infant to sign: Loulis learned 47 signs • Learned somewhat complex strings= 4 year old child. • Koko the gorilla also signs and shows signs of prosody • http://www.youtube.com/watch?v=X67zBy0IQqw&feature=related • http://www.youtube.com/watch?v=_j1Hq8L28Us