Language and the Brain

  Language and the Language and the Brain Brain Helena Helena Gao Gao

Lecture 3 12 Oct., 2005 Lecture 3 12 Oct., 2005 Lecture 3; Oct. 12, 2005 Required readings:

  Required readings:  Gazzaniga, M., Ivry, R., & Mangun, G.

  Vygotsky, L. (1996). Thought and Language.

  Shapiro, K., & Caramazza, A. (2003). The Shapiro, K., & Caramazza, A. (2003). The representation of grammatical categories in representation of grammatical categories in the brain. Trends in Cognitive Science, 7(5), the brain. Trends in Cognitive Science, 7(5), 201-206.

  Recommended readings: Recommended readings: 

  Roots of Thought and Speech. pp. 68-95.

  The MIT Press. Chapter 4: The Genetic The MIT Press. Chapter 4: The Genetic Roots of Thought and Speech. pp. 68-95.

  Newly revised and edited by Alex Kozulin.

  

Newly revised and edited by Alex Kozulin.

   Vygotsky, L. (1996). Thought and Language.

  Gazzaniga, M., Ivry, R., & Mangun, G.

  351-399.

  351-399.

  

Co. Chapter 9: Language and the brain, pp.

  Cognitive Neuroscience: The Biology Cognitive Neuroscience: The Biology of the Mind. New York: W.W. Norton and of the Mind. New York: W.W. Norton and

Co. Chapter 9: Language and the brain, pp.

  (2001).

  (2001).

  201-206. Brain areas involved in Language

Three major types of Three major types of Aphasia Aphasia Rosenzweig: Table 19.1, p. 615 Rosenzweig: Table 19.1, p. 615

   Borca’s aphasia

  Borca’s aphasia 

  Nonfuent speech Nonfuent speech

   Wernicke’s aphasia

  Wernicke’s aphasia 

  Fluent speech but unintelligible Fluent speech but unintelligible

   Global aphasia

  Global aphasia 

  Total loss of language Total loss of language

  Others Others

  : Conduction, Subcortical, : Conduction, Subcortical,

  Transcortical Motor/Sensory (see also Transcortical Motor/Sensory (see also

  Kandel, Table 59-1) Kandel, Table 59-1)

Broca’s Aphasia Broca’s Aphasia Brodmann 44, 45 Brodmann 44, 45

  

Lesions in the left inferior frontal region

  

Lesions in the left inferior frontal region

(Broca’s area)

  (Broca’s area) 

  

Nonfuent, labored, and hesitant speech

Nonfuent, labored, and hesitant speech

   Most also lost the ability to name persons

  Most also lost the ability to name persons or subjects (anomia) or subjects (anomia)

   Can utter automatic speech (“hello”)

  Can utter automatic speech (“hello”) 

  Comprehension relatively intact Comprehension relatively intact

   Most also have partial paralysis of one

  Most also have partial paralysis of one side of the body (hemiplegia) side of the body (hemiplegia)

   If extensive, not much recovery over time

  If extensive, not much recovery over time

Wernicke’s Wernicke’s Aphasia Aphasia Brodmann 22, 30 Brodmann 22, 30

   Lesions in posterior of the left superior

  Lesions in posterior of the left superior temporal gyrus, extending to adjacent temporal gyrus, extending to adjacent parietal cortex parietal cortex

   Fluent speech

  Fluent speech 

  But contains many paraphasias But contains many paraphasias

   “

  “ girl”-“curl”, “bread”-“cake” girl”-“curl”, “bread”-“cake”

   Syntactical but empty sentences

  Syntactical but empty sentences 

  Cannot repeat words or sentences Cannot repeat words or sentences

   Unable to understand what they read or hear

  Unable to understand what they read or hear 

  Usually no partial paralysis Usually no partial paralysis

  

Sign Languages

Sign Languages

  

Full-fedged languages, created by hearing-

  

Full-fedged languages, created by hearing-

impaired people ( impaired people ( not not by Linguists): by Linguists):

   Dialects, jokes, poems, etc.

  Dialects, jokes, poems, etc.

   Do not resemble the spoken language of the same

  Do not resemble the spoken language of the same area (ASL resembles Bantu and Navaho) area (ASL resembles Bantu and Navaho)

   Pinker: Nicaraguan Sign Language

  Pinker: Nicaraguan Sign Language 

  Another evidence of the origins of language Another evidence of the origins of language

  (gestures) (gestures)

   Most gestures in ASL are with right-hand, or

  Most gestures in ASL are with right-hand, or else both hands (left hemisphere dominance) else both hands (left hemisphere dominance)

   Signers with brain damage to similar regions

  Signers with brain damage to similar regions show aphasia as well show aphasia as well

  

Spoken and Sign

Languages

Spoken and Sign

  

Languages



  Neural mechanisms are similar Neural mechanisms are similar

   fMRI studies show similar fMRI studies show similar activations for both hearing and deaf activations for both hearing and deaf

   But in signers, homologous

  But in signers, homologous activation on the right hemisphere is activation on the right hemisphere is unanswered yet unanswered yet

  

Dyslexia

Dyslexia

   Problem in learning to read

  Problem in learning to read 

  Common in boys and left-handed Common in boys and left-handed

   High IQ, so related with language only

  High IQ, so related with language only 

  Postmortem observation revealed Postmortem observation revealed

anomalies in the arrangement of cortical

anomalies in the arrangement of cortical

cells cells

   Micropolygyria: excessive cortical folding

  Micropolygyria: excessive cortical folding 

  Ectopias: nests of extra cells in unusual location Ectopias: nests of extra cells in unusual location

   Might have occurred in mid-gestation,

  Might have occurred in mid-gestation, during cell migration period during cell migration period

  Acquired Dyslexia = Acquired Dyslexia =

Alexia

  Problems with nonsense words 

  One focused on the meanings of whole words 

   One focused on the meanings of whole words

  Suggests 2 diferent systems: Suggests 2 diferent systems:

  Nonsense words are fne 

   Nonsense words are fne

  Surface dyslexia (pays attn. to details): Surface dyslexia (pays attn. to details):

   Problems with nonsense words

  

Alexia



  Fails to see small diferences (do not read each letter) letter)

   Fails to see small diferences (do not read each

  “ “ cow” -> “horse”, cannot read abstract words cow” -> “horse”, cannot read abstract words

  Deep dyslexia (pays attn. to wholes): 

   Deep dyslexia (pays attn. to wholes):

  Disorder in adulthood as a result of disease Disorder in adulthood as a result of disease or injury or injury

  The other on the sounds of words The other on the sounds of words

  

Electrical Stimulation

Electrical Stimulation

   Penfeld and Roberts (1959): During epilepsy

  Penfeld and Roberts (1959): During epilepsy surgery under local anesthesia to locate surgery under local anesthesia to locate cortical language areas, stimulation of: cortical language areas, stimulation of:

   Large anterior zone:

  Large anterior zone:  stops speech stops speech

   Both anterior and posterior temporoparietal

  Both anterior and posterior temporoparietal cortex: cortex:

   misnaming, impaired imitation of words misnaming, impaired imitation of words

   Broca’s area:

  Broca’s area:  unable comprehend auditory and visual semantic

unable comprehend auditory and visual semantic

material, material,

   inability to follow oral commands, point to objects, and inability to follow oral commands, point to objects, and understand written questions understand written questions

PET by Posner and PET by Posner and Raichle (1994) Raichle (1994)

  But if semantic association: 

  Due to phonetic alphabet of Italian… (“ghotia”)

   Due to phonetic alphabet of Italian… (“ghotia”)

  Slightly diferent regions Slightly diferent regions

  Native speaker of Italian and English: 

   Native speaker of Italian and English:

  

All language areas including Broca’s area

All language areas including Broca’s area

   Passive hearing of words activates:

  Passive hearing of words activates: 

  No activation in Broca’s area No activation in Broca’s area

  While reading and repeating: 

   While reading and repeating:

  Both motor cortices, the supplemental motor Both motor cortices, the supplemental motor cortex, portion of cerebellum, insular cortex cortex, portion of cerebellum, insular cortex

  Repeating words activates: 

   Repeating words activates:

  Temporal lobes Temporal lobes

   But if semantic association:

  

PET by Damasio (1989)

PET by Damasio (1989)

   Diferent areas of left hemisphere (other than

  Diferent areas of left hemisphere (other than

Broca’s and Wernicke’s regions) are used to

  

Broca’s and Wernicke’s regions) are used to

name (1) tools, (2) animals, and (3) persons

name (1) tools, (2) animals, and (3) persons

   Stroke studies support this claim

  Stroke studies support this claim 

  

Three diferent regions in temporal lobe are

Three diferent regions in temporal lobe are

used used

  

ERP studies support that word meaning are

  

ERP studies support that word meaning are

on temporal lobe (may originate from on temporal lobe (may originate from

  Wernicke’s area): Wernicke’s area):

   “

  “ the man started the car engine and stepped on the man started the car engine and stepped on the pancake” the pancake”

  

Takes longer to process if grammar is involved

  

Takes longer to process if grammar is involved

  

Williams Syndrome

Williams Syndrome

  Developmental process is altered: 

  Karmilof-Smith, claims the otherwise: 

  Guest speaker in the colloquium, Annette Karmilof-Smith, claims the otherwise:

   Guest speaker in the colloquium, Annette

  Language skills poor at infancy, greatly improved in adulthood in adulthood

   Language skills poor at infancy, greatly improved

  Number skills good at infancy, poor at adulthood Number skills good at infancy, poor at adulthood

   Developmental process is altered:

   Caused by the deletion of a dozen genes from

  But cannot tie their shoe laces, draw images, etc.

  Fluent in language  But cannot tie their shoe laces, draw images, etc.

   Fluent in language

  Shows dissociation between language and intelligence, patients are: intelligence, patients are:

   Shows dissociation between language and

  Caused by the deletion of a dozen genes from one of the two chromosomes numbered 7 one of the two chromosomes numbered 7

  Development alters the end result of the syndrome (?) Development alters the end result of the syndrome (?)

  Lateralization of the Lateralization of the

Brain

  

Brain



  

Human body is asymmetrical: heart,

Human body is asymmetrical: heart, liver, use of limbs, etc. liver, use of limbs, etc.

   Functions of the brain become

  Functions of the brain become lateralized lateralized

   Each hemisphere specialized for

  Each hemisphere specialized for particular ways of working particular ways of working

   Split-brain patients are good examples

  Split-brain patients are good examples

of lateralization of language functions

of lateralization of language functions

Lateralization of Lateralization of functions functions (approximate) (approximate)

   Right-hemisphere:

   Right-hemisphere:

  Left-hemisphere: Left-hemisphere:

   Simultaneous analysis

  Simultaneous analysis 

  Sequential analysis Sequential analysis

   Synthetic Synthetic

   Analytical

  Analytical 

  Visual-Spatial skills Visual-Spatial skills

   

  Problem solving Problem solving Cognitive maps Cognitive maps

   Personal space Personal space

   Language

  Language 

  Facial recognition Facial recognition

   Drawing Drawing

   Emotional functions

  Emotional functions 

  Recognizing emotions Recognizing emotions

   Expressing emotions Expressing emotions

   Music

  Music

Other studies Other studies

   Right ear advantage in dicothic listening:

  Right ear advantage in dicothic listening: 

  Due to interhemispheric crossing Due to interhemispheric crossing

   Words in left-hemisphere, Music in right

  Words in left-hemisphere, Music in right 

  Supported by damage and imaging studies Supported by damage and imaging studies

   But perfect-pitch is still on the left

  But perfect-pitch is still on the left 

  Asymmetry in planum temporale: Asymmetry in planum temporale:

   Musicians with perfect-pitch has 2x larger PT

  Musicians with perfect-pitch has 2x larger PT 

  Evident in newborns, thus suggesting innate Evident in newborns, thus suggesting innate basis for cerebral specialization for language basis for cerebral specialization for language and speech and speech

  

The Storage of Words and

The Storage of Words and

  

Concepts: The Mental

Lexicon

Concepts: The Mental

  

Lexicon



  The Mental Lexicon: The Mental Lexicon:

   a mental store of information about word that includes a mental store of information about word that includes

semantic information, syntactic information, and the

semantic information, syntactic information, and the

details of word forms. details of word forms.

   Most psycholinguistic theories agree on the

  Most psycholinguistic theories agree on the central role for a mental lexicon in language central role for a mental lexicon in language

   Some theories propose one mental lexison for both

  Some theories propose one mental lexison for both language comprehension and production language comprehension and production

   Other models distinguish between input and

  Other models distinguish between input and output lexia output lexia

  

  

The representation of orthographic and phonological

forms must be considered in any model. forms must be considered in any model.

The representation of orthographic and phonological

  

The mental lexicon is thought to be organized as information-specifc networks

• – a model proposed by William Levelt in 1994

  

Support for the model

Support for the model

   Semantic Priming Studies

  Semantic Priming Studies 

  Using a lexical decision task Using a lexical decision task

   Subjects are faster and more accurate at

  Subjects are faster and more accurate at making the lexicon decisions when the target is making the lexicon decisions when the target is proceeded by a related prime (e.g., car truck) proceeded by a related prime (e.g., car truck) than a unrelated prime (e.g., whip truck). than a unrelated prime (e.g., whip truck).

   Expectancy-induced priming might occur if the

  Expectancy-induced priming might occur if the time bet. The presentation of primes and time bet. The presentation of primes and targets is long (e.g., > 500 msec) and the targets is long (e.g., > 500 msec) and the proportion of related word pairs are like car-

proportion of related word pairs are like car-

truck, cat-dog, etc. truck, cat-dog, etc.

  The Nature of Conceptual The Nature of Conceptual

or Semantic Representation

or Semantic Representation

   Question:

  Question: 

  Is the same conceptual representation of a Is the same conceptual representation of a robin activated regardless of whether one robin activated regardless of whether one

hears the word robin or sees one fying?

hears the word robin or sees one fying?

   A model proposed by Collins and Loftus

  A model proposed by Collins and Loftus (1975)

  (1975) 

  Word meanings are represented in a Word meanings are represented in a semantic network in which words, semantic network in which words, represented by conceptual nodes, are represented by conceptual nodes, are connected with each other. connected with each other.

• Although this semantic network model (Collins & Loftus, 1975)has been extremely infuential, it is a matter of debate how Word meanings are represented.
• No matter how they are represented, it is agreed that a mental store of word meanings is crucial to normal language comprehension and production.

  Support from neurological Support from neurological

evidence for the semantic network

evidence for the semantic network

idea idea

   Diferent types of neurological problems create

  Diferent types of neurological problems create defcits in understanding and producing the defcits in understanding and producing the appropriate meaning of a word or concept. appropriate meaning of a word or concept.

  Patients with Wernicke’s aphasia makes errors Patients with Wernicke’s aphasia makes errors in speech production that are known as in speech production that are known as semantc-paraphasias (e.g., using the word semantc-paraphasias (e.g., using the word horse horse to mean to mean cow cow

  ) )

  

Patients with progressive-semantic dementia

  

Patients with progressive-semantic dementia

initially show impairments in the conceptual initially show impairments in the conceptual system, while other mental and language system, while other mental and language abilities are spared. abilities are spared.

  

Evidence from research done by E.

Evidence from research done by E

  

Warrington (1970s-1980s)

Warrington (1970s-1980s)

   Findings: semantic problem can be

  Findings: semantic problem can be localized specifcally to certain semantic localized specifcally to certain semantic categories , such as animals versus categories , such as animals versus objects. objects.

   E.g., patients who had great dificulties

  

E.g., patients who had great dificulties

pointing to pictures of food or living pointing to pictures of food or living things when presented with a word, things when presented with a word, whereas their performance with man- whereas their performance with man- made objects like tools was much better. made objects like tools was much better.

Evidence from H. Damasio and her Evidence from H. Damasio and her colleagues’ studies (1996) colleagues’ studies (1996)

   Investigated a large population of patients with brain

  Investigated a large population of patients with brain lesions lesions

  

A naming task in three diferent conditions: (1) naming

  

A naming task in three diferent conditions: (1) naming

famous faces, (2) naming animals, and (3) naming tools

famous faces, (2) naming animals, and (3) naming tools

   30 patients, 29 of whom had a lesion in the left

  30 patients, 29 of whom had a lesion in the left hemisphere, showed impairments in this task. hemisphere, showed impairments in this task.

  

7 patients demonstrated impairment in naming faces, 5

  

7 patients demonstrated impairment in naming faces, 5

in naming animals; and 7 in naming tools. The remaining in naming animals; and 7 in naming tools. The remaining

  

11had a combination of problems in word retrieval for

11had a combination of problems in word retrieval for

faces, animals, and tools, faces and animals, or animals

faces, animals, and tools, faces and animals, or animals

and tools, but never for the combination of faces and and tools, but never for the combination of faces and tools together without also a defcit in animals. tools together without also a defcit in animals.

  

Location of the brain lesions that are correlated with selective defcits in naming persons, animals,

or, tools. (Damasio et al (1996)

Pet Scanning

• Brain damage in the left temporal pole (TP) correlated with problems in retrieving the names of persons
• Lesions in the anterior part of the Left inferior temporal (IT) lobe correlated with problems in naming animals
• Damage to the posterolaterol part of the left inferior temporal lobe, along with lateral temporo-occipito-parietal junction (IT+), was correlated with problems in retrieving the names of tools

  

Three levels of Representation for Word Knowledge – predicated by cognitive models of word

Production Based on Damasio et al’s Results (Caramazza, 1996)

  Schematic representation of the components that are involved in spoken and written language comprehension.

  Input can enter via either auditory (spoken word) or visual (written word) modalities.

  The fow of info is bottom up, from Perceptual identifcation to “higher-level” word and lemma activation.

  Interactive models of language Understanding would predict top-down

  Spoken Input – lack of segmentation

  Spectral properties vary according to sounds (Klatt, 1989) A model for letter recognition, the pandemonium model (Selfridge, 1959)

  M cC le lla nd , J .L ., an d R um el ha rt, D .E . (

  19

  86 ).

  Pa ra lle l D is tr ib ut ed P ro ce ss in g: E xp lo ra tio ns in th e

  M ic ro st ru ct ur e of C og ni tio n.

  V ol . 2 : P

  sy ch ol og ic al a nd B io lo gi ca l M od el s.

  C am br id ge , M A : M

  IT P re ss .

  

Fragment of a connectionist network for letter recognition (McCleland & Rumelhart, 1981)

  A cohort model of British psychologist William Marslen –Wilson (Marslen –Wilson & Tyler, 1980)

  3

• 7

  

ERPs recorded in response to sentences that start with before (dashed lines) and after (solid lines)

  71 5: Munte et al (1998).

  39

  e ur at

  Task: “After/Before the scientist submitted the paper, the journal changed its policy”

  . N er rd l o

  Before are

  ua pt

  More

  ce on c

  Negative in

  ie el

  polarity

  s b m er l t ra po m te n he W ).

  98

  19 . ( , M as ut K d an

  ., , K lz hi Sc ., .F , T te ün

  

Summary of lesions in the anterior superior temporal cortext that lead to defcits in

Syntactic processing (Mazoyer et al, 1993)

• W . ( Ed s.) , L in gu is tic D

  A da pt ed fr om L ev el t, W .J. M ., Th e A rc hi te ct ur e of N or m al S po ke n La ng ua ge U se , i n B la nk en , G ., D itt m an ,

  J., G rim m , H ., M ar sh al l, J.C ., an d W al le sh , C

  is or de rs a nd P at ho lo gi es : A n

  In te rn at io na l H an db oo k.

  B er lin : W al te r d e G ru yt er , 1

  99

  3

Speech Production

  Outline of the theory of speech production developed by William Levelt (1999)

• 5

  A da pt ed fr om v an T ur en no ut , M . H ag oo rt, P ., an d B ro w n, C .M . (

  19

  99 ). B ra in a ct iv ity d ur in g sp ea ki ng :

  Fr om sy nt ax to p ho no lo gy in 4 m ill is ec on ds . S ci en ce , 2

  80 , 5

  72

  74 .

  A study to test whether Lemma selection indeed Precedes activation of Appropriate lexeme (as In Levelt’s model) by Van turennout (1999) Method: Stimuli: words in Dutch -> Equ.: ERP Proc.: Subjects were asked to make a response only when the words representing the pic. Started with a “b’, and to withdraw their response when the word Started with a “s”.