Psy1306 Language and Thought Lectures 4 Color Lateralization

Qs previous students asked Something I noticed from this week's readings was that they seemed to be doing a study, finding that it didn't really fit their hypothesis, and then doing another study to try and cover their tracks. Maybe that is alright, but it seems that they were chasing their answer with study after study, and some confirmation bias might have weasled its way into their results. Something I noticed from this week's readings was that they seemed to be doing a study, finding that it didn't really fit their hypothesis, and then doing another study to try and cover their tracks. Maybe that is alright, but it seems that they were chasing their answer with study after study, and some confirmation bias might have weasled its way into their results. What do they mean by "codability"? What do they mean by "codability"?

Qs previous students asked Why do the experimenters investigating language's influence on color perception select blue and green for their studies? Are these colors more often grouped under one category heading in various languages than other color pairs, or is there something about the way that humans actually perceive green and blue that could affect the results of these studies? Why do the experimenters investigating language's influence on color perception select blue and green for their studies? Are these colors more often grouped under one category heading in various languages than other color pairs, or is there something about the way that humans actually perceive green and blue that could affect the results of these studies? In experiment 2 in Kay and Kempton's article, the Whorfian effect was eliminated when the middle paint chip was labeled immediately. However, do participants say that a chip "looks different" because they actually think it looks different from the target, or do they make this assertion so they can justify their decision without necessarily believing their own choice? In experiment 2 in Kay and Kempton's article, the Whorfian effect was eliminated when the middle paint chip was labeled immediately. However, do participants say that a chip "looks different" because they actually think it looks different from the target, or do they make this assertion so they can justify their decision without necessarily believing their own choice?

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

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

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

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

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

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

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

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

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

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

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

A Man with Two Brains 000&e= &e= With communication between his left and right hemispheres severed, a patient teaches doctors about the division of labor within the brain. Language in the brain Lateralization: Left vs. Right Hemisphere

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

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

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

Functions of the Hemispheres Left Hemisphere Left Hemisphere –Rapid language processing –Lexical, syntactic processing –Phonemic processing Right Hemisphere Right Hemisphere –Higher level processing –Discourse processing –Prosodic information 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 Patient data provide evidence that there are regions of the brain associated with language processing Data from normals corroborate brain damage data Data from normals corroborate brain damage data The evidence is suggestive of brain modularity – i.e. specialized areas for processing language. The evidence is suggestive of brain modularity – i.e. specialized areas for processing language. Language in the brain Lateralization: Left vs. Right Hemisphere

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

When does lateralization emerge? rage/scientific/pbssaf703_220k.asf&s= &e= rage/scientific/pbssaf703_220k.asf&s= &e= Videoclip touches upon: EEG/ERP technology Lateralization emergence Critical Period in Second Language Acquisition Issues of Plasticity Competition of processes Language in the brain Lateralization: Emergence

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…. 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….

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

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

Experiment 1

Experiment 2: Visual or Verbal Interference

Experiment 2

What does the result say: Eliminate lateralized effect 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?

Experiment 3: Split Brain 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, & Hanley (2008)

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

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).

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 (~ ms) increased negativity at occipital and extrastriate sites that is lateralized mostly to the LH, and a later (~ ms) increased negativity at frontal sites that is observed bilaterally.

Tan, Chan, Kay, Khong et al.

52 Tan et al Language affects patterns of brain activation associated with perceptual decision. PNAS

53 Tan et al Language affects patterns of brain activation associated with perceptual decision. PNAS “ Crucially, perceptual discrimination of easy-to- name colors evoked stronger activation in … two regions responsible for word finding processes…. This finding suggests that the language processing areas of the brain are directly involved in visual perceptual decision, thus providing neuroimaging support for the Whorf hypothesis.” from the abstract

INFANTS? Franklin et al. (2008)

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