Psy1306 Language and Thought Lectures 4 Color Lateralization.

Psy1306 Psy1306 Language and ThoughtLanguage and Thought

Lectures 4Lectures 4

Color LateralizationColor Lateralization

Left Brain Right Brain

Left Body Right Body

Contralateral ControlContralateral Control(as opposed to ipsilateral control)(as opposed to ipsilateral control)

1860s: investigators apply electric 1860s: investigators apply electric currents to brains of anesthetized currents to brains of anesthetized animals and made an interesting animals and made an interesting discovery.discovery.

Language in the brainLateralization: Left vs. Right Hemisphere

Split-Brain ResearchSplit-Brain Research(Sperry, Gazzaniga, (Sperry, Gazzaniga, etc.)etc.)

Surgically Lesioned Corpus Surgically Lesioned Corpus CallosumCallosum– ““cure” for epilepsycure” for epilepsy

Post-surgery:Post-surgery:– Normal BehaviorNormal Behavior


Testing Split-Brain PatientTesting Split-Brain Patient

General Testing Setup.


Patient says: “Spoon!”

Name that object Name that object (picture in RVF)(picture in RVF)


Patient: (says nothing)Researcher: “Did you see any thing?”Patient: “Nope.”

Name that objectName that object(picture in LVF)(picture in LVF)


Left Visual Field Right Visual Field

Left Brain Right Brain

Left Body Right Body


Right Hand: Pulls out Spoon!Left Hand does nothing

Pick up the object displayedPick up the object displayed


Left Hand: Pulls out Spoon!Right hand does nothing

Pick up the object displayedPick up the object displayed


LH rationalizing behavior of LH rationalizing behavior of RHRH


Typical Split Brain Typical Split Brain PatientPatient Left Brain:Left Brain:

– Normal Language UseNormal Language Use– Speaking and listeningSpeaking and listening

– No easily detectable deficits.No easily detectable deficits. Right Brain:Right Brain:

– Some rudimentary word recognition.Some rudimentary word recognition.


Split-brain patient and Split-brain patient and Dichotic Listening Dichotic Listening What does the patient report hearing in all three cases?


A Man with Two BrainsA Man with Two Brains

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.


American Sign Language American Sign Language (ASL)(ASL)

Deaf Signers with Left Hemisphere Deaf Signers with Left Hemisphere Damage:Damage:– Language Deficit. Aphasic.Language Deficit. Aphasic.

Deaf Signers with Right Hemisphere Deaf Signers with Right Hemisphere Damage:Damage:– Visio-Spatial Deficits.Visio-Spatial Deficits.– No easily detectable language deficits.No easily detectable language deficits.

Left Hemisphere implicated in Left Hemisphere implicated in LanguageLanguage

Poizner, Klima, & Bellugi (1987)


Native ASL Signers – Native ASL Signers – RH vs. LH RH vs. LH damagedamage

Hickok et al. (1998)


Native ASL Signers – Native ASL Signers – RH vs. LH RH vs. LH damagedamage

Comparisons on:Comparisons on: ProductionProduction ComprehensionComprehension Phrase repetition Phrase repetition

TestTest Naming TestNaming Test Rhyming TestRhyming Test Paraphasias/min Paraphasias/min

(#speech error/min)(#speech error/min)Hickok et al. (1996)


Functions of the Functions of the HemispheresHemispheres

Left HemisphereLeft Hemisphere– Rapid language Rapid language

processingprocessing– Lexical, syntactic Lexical, syntactic

processing processing – Phonemic Phonemic

processingprocessing

Right Right HemisphereHemisphere– Higher level Higher level

processingprocessing– Discourse Discourse

processingprocessing– Prosodic Prosodic

informationinformation


Summary: Summary: Brain and modularityBrain and modularity Patient data provide evidence that Patient data provide evidence that

there are regions of the brain there are regions of the brain associated with language associated with language processingprocessing

Data from normals corroborate Data from normals corroborate brain damage databrain damage data

The evidence is suggestive of brain The evidence is suggestive of brain modularity – i.e. specialized areas modularity – i.e. specialized areas for processing language.for processing language.


When does lateralization When does lateralization emerge?emerge? Quickly within the first few years of life.Quickly within the first few years of life.

– Dichotic listening task (Kimura,1963): Dichotic listening task (Kimura,1963): 4-6 yr-olds show right-ear advantage4-6 yr-olds show right-ear advantage

– EEG/ERP data (Neville et al.)EEG/ERP data (Neville et al.) 4-6 yr-olds4-6 yr-olds

– High-amplitude sucking (Bertoncini et al. High-amplitude sucking (Bertoncini et al. 1989): 1989):

Neonates (4-day-olds) Neonates (4-day-olds) – Right-ear advantage for syllable changeRight-ear advantage for syllable change– Left-ear advantage for musical tone changeLeft-ear advantage for musical tone change

Language in the brainLateralization: Emergence

When does lateralization When does lateralization emerge?emerge?

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

Language in the brainLateralization: Emergence

Winawer, Witthoft, Frank, Winawer, Witthoft, Frank, Wu, Wade, Boroditsky Wu, Wade, Boroditsky (2007)(2007) Pinker: Most of the experiments Pinker: Most of the experiments

have tested banal “weak” have tested banal “weak” versions of the Whorfian versions of the Whorfian hypothesis, namely that words hypothesis, namely that words can have some effect on memory can have some effect on memory or categorization….or categorization….

Goluboy (light blue) Siniy (dark blue)

Winawer, Witthoft, Frank, Winawer, Witthoft, Frank, Wu, Wade, Boroditsky (2007)Wu, Wade, Boroditsky (2007)

Gilbert, A., Regier, T., Gilbert, A., Regier, T., Kay, P., & Ivry, R. Kay, P., & Ivry, R. (2006)(2006)

Pre-screen participants by color naming.Pre-screen participants by color naming.

Actual Task: Detect discrepant color and Actual Task: Detect discrepant color and press button for L-R side.press button for L-R side.

Experiment 1Experiment 1

Experiment 2: Visual Experiment 2: Visual or Verbal Interferenceor Verbal Interference

Experiment 2Experiment 2

What does the result What does the result say:say: Eliminate lateralized effectEliminate lateralized effect

– Linguistic categories are activated Linguistic categories are activated on-line (i.e., against learning on-line (i.e., against learning warping perceptual space)warping perceptual space)

– Though still unanswered: is the Though still unanswered: is the effect during perception or post-effect during perception or post-perceptual?perceptual?

Experiment 3: Split Experiment 3: Split Brain PatientBrain Patient

Is (near) restriction of CP to RVF limited to color?

Answer: No.

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

Dog and cat stimuli

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)

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)

What about other languages? Two early reports.

Roberson, Pak, & Roberson, Pak, & Hanley (2008)Hanley (2008)

(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.)

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.

EEG experiment protocol. Aubrey Gilbert’s Dissertation (Berkeley, 2007).

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Target200 ms

Cross - category LVF deviant

200 ms +

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Fixation[800 - 1200 ms]

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Within - category RVF deviant

200 ms

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Standard200 ms





Standard200 ms

Standard200 ms

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Target200 ms

Cross - category LVF deviant

200 ms +

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oo

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Within - category RVF deviant

200 ms

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Standard200 ms





Standard200 ms

Standard200 ms

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.

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

5252

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

5353

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

““Crucially, perceptual discrimination of easy-Crucially, perceptual discrimination of easy-to-name colors evoked stronger activation in … to-name colors evoked stronger activation in … two regions responsible for word finding two regions responsible for word finding processes…. This finding suggests that the processes…. This finding suggests that the language processing areas of the brain are language processing areas of the brain are directly involved in visual perceptual decision, directly involved in visual perceptual decision, thus providing neuroimaging support for the thus providing neuroimaging support for the Whorf hypothesis.” Whorf hypothesis.”

from the abstractfrom the abstract

PATIENTS CONTROLS

Figure 13. Results of 15 aphasic patients and 12 controls tested on the no-interference visual search task of Gilbert, et al. (2006). Source: Paluy, Y ., Gilbert, A.L., Baldo, J.V., & Ivry, R.B. (2007, August). Is Whorf Right? (or Left?). Poster presented at the 29th Annual Cog nitive Science Society. Nashville, TN

INFANTS? Franklin et INFANTS? Franklin et al. (2008)al. (2008)

The category effect for adults is significant in both visual fields, but is larger in the RVF than in the LVF

Psy1306 Language and Thought Lectures 4 Color Lateralization.

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