Language Use and Understanding

1. Language Use and Understanding BCS 261 LIN 241 PSY 261 CLASS 10: BRAIN AND LANGUAGE

2. Organization of Class • Section 1: Conversation / Discousre • processes involved in the production, interpretation, and representation of information that spans two or more utterances • Language as a communicative endeavor • Section 2: Lower-level processes • Segueway: Brain and Language • Cognitive Processes of Production • Cognitive Processes of Comprehension

3. What is the neural basis of language processing • What you should get out of this class and the assigned readings: • What are the kinds of questions researchers have asked about language in the brain? • What do we know about the neural structures underlying language use?, • What still needs to be learned? • What techniques are used to study these questions?

4. Readings • Ojemann: Overview article: • how is language organized in the brain? • What is known about the neural basis for language processing? • Neville et al.: Deaf vs. Hearing signers • Damasio et al.: Lexical retrieval • Different brain regions specialized for word classes

5. The forebrain • Left/Right Hemi. • 4 Lobes

6. Primary Motor Projection Areas • Departure points for nerve cells that send signals for motor movement to lower parts of brain & spinal cord • Contralateral control

7. Sylvian fissure

8. Figure 02.06

9. Speech areas

10. Ojemann (1991): Cortical Organization of Language • Old textbook model: serial processing • Decoding in Wernike’s area • Expression in Broca’s area • New model: • Same important areas (perisylvian fissure) • Different systems for different functions • Essential areas • Network of neurons • Parallel • Lateral specialization • Individual Variation

11. Functional specialization • Dissociation or • Double dissociation • DISCUSSION Q: Is it possible to disrupt an area that is responsible for speech comprehension without disrupting the ability to read? (Jessica DeSisto)

12. Discussion Qs • Is Ojeman a supporter of motor theory of production? (Anthony Shook) • The author makes many references to areas of the brain that are dedicated to language. Does he get this information mostly from monolingual people or mostly from bilingual people? Would there be a difference in brain structure between monolingual and bilingual people? (Jesse Blake)

13. Damasio et al. (1996): A neural basis for lexical retrieval • What neural structures activated when you retrieve a word? • Proposal: different areas for different classes of words • Unique persons • Non-unique animals • Non-unique tools

14. Lesion study • 327 patients • Naming task • 327 visually presented items in three categories • Only included if they recognized object • DISUCSSION Q: How was it determined that an object was recognized and the word was unknown as opposed to an unrecognizable object and unknown name? (Beth Riina)

15. Finding #1: disruption only in L hemi. • Patients with normal naming -- half with damage in left hemisphere • Patients with abnormal naming -- almost all with damage in left hemisphere

16. Finding #2: naming disruption correlated with different sites for different categories • Word-retrieval problems always involved persons/animals or animals/tools, but never persons/tools • Different lesion areas for problems with different areas • PERSONS: left TP • ANIMALS: left anterior IT • TOOLS: posterolateral IT and junction of lateral temporo-occipito-parietal cortices

17. PET study with normal adults • Same naming task • Control task: say “up” or “down” to pictures of unfamiliar faces • Finding #1: Statistically significant increase in blood flow in left TP/IT for all three tasks • Findng #2: activation in diff areas • persons – left ventrolateral TP but not left IT • animals and tools – left posterior IT and a restricted portion of left TP, but in different areas

18. Discussion Qs • Did the brain damaged subjects studied only have damage to these specific areas mentioned? Or is it possible that brain damage to other areas is the cause of their inability to name people, animals and/or tools? (Jessica DeSisto) • Only three subjects with defects had lesions outsite these sites • Is there a hypothetically infinite amount of separate brain areas that are specialized for categories? To what extent, past these three categories of people, tools, and animals, could the brain be physically categorized? (Anthony Shook)

19. Neville et al. (1998): Cerebral organization for language in deaf and hearing subjects • What leads to language organization in the brain? • Age of acquisition • Ultimate proficiency • How many languages learned and how similar • How early was exposure • What is role of sound-based processeing?

20. fMRI study • Three groups • hearing monolingual English speakers • Congenitally deaf ASL native signers • Bilingual hearing English / native ASL signers • Task: • read English sentences; control: consonant strings • video of ASL sentences; control: nonsign gestures • fMRI measurements: • Mean % change of activation in a region • Mean spatial extent of activation in a region

21. Results: English • Hearing English speakers and Hearing English/ASL bilinguals • Left hemisphere activation in language areas and other areas, little activation on right • Deaf subjects • Right hemisphere activation, little on left • Why is it that the classical language areas within the left hemisphere were not recruited by deaf subjects when reading English? (Jessica DeSisto) • May be due to age of acquisition or tendency to focus on visual form info when reading

22. Results: ASL • Hearing English speakers: no difference between sentences and nonsign gestures • ASL deaf subjects and bilinguals: • Left hemisphere activation in classic language areas and other areas -- acquisition of a spoken language isn’t necessary for this specialization • ALSO right hemisphere activation -- not limited to deaf subjects, so isn’t due to auditory deprivation

23. Discussion Qs • To what extent does the fact that lesions to the RH in signers produce fewer deficits than lesions in the LH speak against the "required recruitment" of the right hemisphere in sign language production? (Anthony Shook) • Note about brain findings: patterns are very rarely absolute… I.e., there is no “required recruitment”

24. Is the fact that the native English speakers learned the aural aspect of their language before learning the visual aspect (which is what this experiment was testing) relevant? I understand the need for visual input for everyone, but are reading and signing really equivalent things to compare? This could even affect the hearing native signers in that they're seeing the "spoken" form of ASL, but the written form of their other native language. (Nicole Dobrowolski)

25. On bilingualism with ASL and spoken language • Is bilingualism in ASL and a spoken language the same, in terms of cerebral activation and processing, as would be 2 spoken languages? (Beth Riina) • According to the Neville et al. article classical language areas lie within the left hemisphere. Will my bilingual students who are acquiring the English language at six years old develop a left and right pattern of activation for reading? (MR)