Psy1306 Language and Thought

1. Psy1306 Language and Thought Lectures 4 Color Lateralization

2. Language in the brain Contralateral Control(as opposed to ipsilateral control) Lateralization: Left vs. Right Hemisphere • 1860s: investigators apply electric currents to brains of anesthetized animals and made an interesting discovery. Right Brain Left Brain Left Body Right Body

3. Language in the brain Split-Brain Research(Sperry, Gazzaniga, etc.) Lateralization: Left vs. Right Hemisphere • Surgically Lesioned Corpus Callosum • “cure” for epilepsy • Post-surgery: • Normal Behavior

5. Language in the brain Testing Split-Brain Patient Lateralization: Left vs. Right Hemisphere General Testing Setup.

6. Language in the brain Name that object (picture in RVF) Lateralization: Left vs. Right Hemisphere Patient says: “Spoon!”

7. Language in the brain Lateralization: Left vs. Right Hemisphere Name that object(picture in LVF) Patient: (says nothing) Researcher: “Did you see any thing?” Patient: “Nope.”

8. Language in the brain Lateralization: Left vs. Right Hemisphere Right Visual Field Left Visual Field Right Brain Left Brain Left Body Right Body

9. Language in the brain Right Hand: Pulls out Spoon! Left Hand does nothing Pick up the object displayed Lateralization: Left vs. Right Hemisphere

10. Language in the brain Left Hand: Pulls out Spoon! Right hand does nothing Pick up the object displayed Lateralization: Left vs. Right Hemisphere

11. Language in the brain LH rationalizing behavior of RH Lateralization: Left vs. Right Hemisphere

12. Language in the brain Typical Split Brain Patient Lateralization: Left vs. Right Hemisphere • Left Brain: • Normal Language Use • Speaking and listening • No easily detectable deficits. • Right Brain: • Some rudimentary word recognition.

13. Language in the brain Split-brain patient and Dichotic Listening Lateralization: Left vs. Right Hemisphere What does the patient report hearing in all three cases?

14. Language in the brain A Man with Two Brains Lateralization: Left vs. Right Hemisphere • http://www.pbs.org/perl/media.cgir?t=w&f=virage/scientific/pbssaf703_220k.asf&s=173000&e=780266 With communication between his left and right hemispheres severed, a patient teaches doctors about the division of labor within the brain.

15. Language in the brain American Sign Language (ASL) Lateralization: Left vs. Right Hemisphere • Deaf Signers with Left Hemisphere Damage: • Language Deficit. Aphasic. • Deaf Signers with Right Hemisphere Damage: • Visio-Spatial Deficits. • No easily detectable language deficits. • Left Hemisphere implicated in Language Poizner, Klima, & Bellugi (1987)

16. Language in the brain Native ASL Signers – RH vs. LH damage Lateralization: Left vs. Right Hemisphere Hickok et al. (1998)

17. Language in the brain Comparisons on: Production Comprehension Phrase repetition Test Naming Test Rhyming Test Paraphasias/min (#speech error/min) Native ASL Signers – RH vs. LH damage Lateralization: Left vs. Right Hemisphere Hickok et al. (1996)

18. Language in the brain Left Hemisphere Rapid language processing Lexical, syntactic processing Phonemic processing Right Hemisphere Higher level processing Discourse processing Prosodic information Functions of the Hemispheres Lateralization: Left vs. Right Hemisphere

19. Language in the brain Lateralization: Left vs. Right Hemisphere Summary: Brain and modularity • Patient data provide evidence that there are regions of the brain associated with language processing • Data from normals corroborate brain damage data • The evidence is suggestive of brain modularity – i.e. specialized areas for processing language.

20. Language in the brain When does lateralization emerge? Lateralization: Emergence • Quickly within the first few years of life. • Dichotic listening task (Kimura,1963): • 4-6 yr-olds show right-ear advantage • EEG/ERP data (Neville et al.) • 4-6 yr-olds • High-amplitude sucking (Bertoncini et al. 1989): • Neonates (4-day-olds) • Right-ear advantage for syllable change • Left-ear advantage for musical tone change

21. Language in the brain http://www.pbs.org/perl/media.cgir?t=w&f=virage/scientific/pbssaf703_220k.asf&s=2677776&e=3334066 Videoclip touches upon: EEG/ERP technology Lateralization emergence Critical Period in Second Language Acquisition Issues of Plasticity Competition of processes When does lateralization emerge? Lateralization: Emergence

22. Winawer, Witthoft, Frank, Wu, Wade, Boroditsky (2007) • Pinker: Most of the experiments have tested banal “weak” versions of the Whorfian hypothesis, namely that words can have some effect on memory or categorization….

23. Winawer, Witthoft, Frank, Wu, Wade, Boroditsky (2007) Goluboy (light blue) Siniy (dark blue)

28. Gilbert, A., Regier, T., Kay, P., & Ivry, R. (2006) • Pre-screen participants by color naming. • Actual Task: Detect discrepant color and press button for L-R side.

29. Experiment 1

30. Experiment 2: Visual or Verbal Interference

31. Experiment 2

32. What does the result say: • Eliminate lateralized effect • Linguistic categories are activated on-line (i.e., against learning warping perceptual space) • Though still unanswered: is the effect during perception or post-perceptual?

33. Experiment 3: Split Brain Patient

34. Is (near) restriction of CP to RVF limited to color? Answer: No.

35. Dog and cat stimuli (Gilbert, A., Regier, T., Kay, P., & Ivry, R. Brain and Language, in press)

36. Fig. 2. Sample display for the visual search task [as in BERKELEY EXP. 1] with a between-categories stimulus pair. Participants were required to press one of two response keys, indicating the side containing the target. (Gilbert, A., Regier, T., Kay, P., & Ivry, R. Brain and Language, in press)

40. Fig. 6. Visual search task results from callosotomy patient testing. Error bars show 95% confidence limits. (Gilbert, A., Regier, T., Kay, P., & Ivry, R. Brain and Language, in press)

41. What about other languages? Two early reports.

42. Roberson, Pak, & Hanley (2008)

43. (Source: Roberson, D. et al., Categorical perception of colour in the left visual field is verbally mediated. Cognition (2007), doi:10.1016/j.cognition.2007.09.001.)

45. Moreover… VF to Brain Hemisphere inference has been confirmed in an Event-Related Potential (ERP) study using the same stimuli as in BERKELEY EXPS. 1 & 2.

46. + + + Standard Standard 200 ms 200 ms + + Fixation Fixation [800 [800 - - 1200 ms] 1200 ms] + + + Cross Cross - - category category LVF deviant LVF deviant + + 200 ms 200 ms Fixation Fixation + + + [800 [800 - - 1200 ms] 1200 ms] Standard Standard + + 200 ms 200 ms Fixation Fixation [800 [800 - - 1200 ms] 1200 ms] o o o Target Target 200 ms 200 ms + + Fixation Fixation [800 [800 - - 1200 ms] 1200 ms] + + + Standard Standard 200 ms 200 ms + + Fixation Fixation [800 [800 - - 1200 ms] 1200 ms] + + + Within Within - - category category RVF deviant RVF deviant 200 ms 200 ms EEG experiment protocol. Aubrey Gilbert’s Dissertation (Berkeley, 2007).

47. Figure 3. Grand-averaged ERPs to standard (in black) and each of the deviant stimuli. The only deviant to evoke ERPs with significant differences from those evoked by standard stimuli was the cross-category deviant (in red) and these differences only occurred when this deviant was presented in the RVF. The significant differences of note are an earlier (~150-300 ms) increased negativity at occipital and extrastriate sites that is lateralized mostly to the LH, and a later (~400-700 ms) increased negativity at frontal sites that is observed bilaterally.

48. Tan, Chan, Kay, Khong et al.

50. Tan et al. 2008. Language affects patterns of brain activation associated with perceptual decision. PNAS 105.10.4004-9.