Language & SpeechLanguage & Speech

June 21, 2011

Review QuizReview Quiz

1. Provide evidence for or against the role of vaccines in autism.

2. Explain the formation of the notochord and/or neural tube, and why this stage of development is important.

3. Describe the major regions (i.e., the structures you modeled with clay yesterday) of the brain and their formation.

DiscussionDiscussion

What is Language?Why Do We Use Speech &

Language?Are Speech & Language Unique to

Humans?

Create Your Own LanguageCreate Your Own Language

RadioLab PodcastRadioLab Podcast

Words, Part 1

Wernicke’s & Broca’s AreaWernicke’s & Broca’s Area

http://www.britannica.com/EBchecked/media/3601/Lateral-surface-of-left-hemisphere-of-brain

Language LateralizationLanguage Lateralization

Areas important to language are primarily located on the left side of the brain.

This is determined using the Wada test.– Anesthetic is injected into one carotid artery to

anesthetize one cerebral hemisphere.

– If language is located here, the person will lose the ability to talk.

The left hemisphere is dominant for speech in approximately 95% of all right-handed people!

So Then, the Right Hemisphere Has So Then, the Right Hemisphere Has No Role in Speech.No Role in Speech.

There is some involvement of the right hemisphere, even though the left hemisphere is dominant.

For example, the right hemisphere is important:– Describing spatial information (maps, etc)– Forming a story– Prosody (melodical rhythm and stresses of

speech)

An Interesting Exception: An Interesting Exception: Case J.M.Case J.M. 16 y.o. white female 8th grade level in self-paced special education

classes No movement on right side of body Cranial deformities & extra bone in skull Left hemisphere hypoplasia diagnosed at age

8– Left frontal lobe missing, area occupied by fluid-

filled cyst– Decreased vasculature on left temporal, parietal,

and occipital lobes

From Lecture by Anthony Y. Stringer, Emory University , 2006

From Lecture by Anthony Y. Stringer, Emory University , 2006

J.M.’s Brain ScanJ.M.’s Brain Scan

Normal Angiogram of Normal Angiogram of J.M.’s Right HemisphereJ.M.’s Right Hemisphere

Angiogram Showing Agenesis

of J.M.’s Left Middle Cerebral Artery

From Lecture by Anthony Y. Stringer, Emory University , 2006

J.M.’s AngiogramsJ.M.’s Angiograms

Boston Diagnostic Aphasia Exam

Repetition

Fluency

Word Discrimination

Complex Comprehension

Responsive Naming

Confrontation Naming

Reading

%ile

70

96

87

85

87

100

90

Kaplan Sentence Arrangement Test 60%

From Lecture by Anthony Y. Stringer, Emory University , 2006

J.M.’s Language ResultsJ.M.’s Language Results

Right Hemisphere and LanguageRight Hemisphere and Language

May take on many language functions in response to severe left hemisphere developmental trauma– Early intractable

epilepsy– Hemisphere

agenesis/hypoplasia– Early left

hemispherectomy But, this comes at a

cost…

From Lecture by Anthony Y. Stringer, Emory University , 2006

Broca’s AphasiaBroca’s Aphasia

Results from damage to Broca’s area and surrounding areas in the left inferior frontal lobe

Slow, labored speech with great difficulty producing words

http://faculty.washington.edu/chudler/functional.html

Role of Broca’s Area in SpeechRole of Broca’s Area in Speech

May be responsible for memories of the motor muscle sequences needed for forming words

Thus, deficits are of 3 types:– Agrammatism: difficulty with grammar– Anomia: difficulty finding a word– Articulation: difficulty pronouncing

words

Difficulties in Broca’s AphasiaDifficulties in Broca’s Aphasia

Meaning of words is correct, but difficult to pronounce– Emphasis on content words, difficulty with function words

Find it much easier to understand speech than to produce it

“kid…kk…can…candy…cookie…candy…well I don’t know but it’s writ…easy does it…slam…early…fall…men…many no…girl. Dishes…soap…soap…water…water…falling pah that’s all…dish…that’s all.”

Physiology of Behavior. 7th edition.

Carlson, N.R.

Needham Heights (MA): Allyn and Bacon; 2001.

Other Regions in Broca's Other Regions in Broca's AphasiaAphasia Left Precentral Gyrus of the Insula

– When damaged, see apraxia (impaired ability to move tongue, lips, and throat)

Periaqueductal Gray of the midbrain– When damaged, see disruptions in

vocalization, even to the extent of mutism

Neocortical damage in the frontal lobe Cerebellum

Wernicke’s AphasiaWernicke’s Aphasia

Results from damage to Wernicke's area in the auditory association cortex on the left temporal lobe

Leads to difficulties in comprehending words and producing meaningful speech

Speech fluidity is maintained

http://faculty.washington.edu/chudler/functional.html

How Does Wernicke’s Aphasia How Does Wernicke’s Aphasia Sound?Sound? “Never, no mista oyge I wann tell you this

happened when happened when he rent. His—his kell come down here and is—he got ren something. It happened. In thesse ropiers were with him for hi—is friend—like was. And it just happened so I don’t know, he did not bring around anything. And he did not pay it. And he roden all o these arranjen from the pedis on from iss pescid. In these floors now and so. He hadn’t had em round here.”

Kertesz, 1981, p. 73

Physiology of Behavior. 7th edition.

Carlson, N.R.

Needham Heights (MA): Allyn and Bacon; 2001.

Wernicke’s ComprehensionWernicke’s Comprehension

When asked to use nonverbal cues to respond to questions, responses of patients reveal that they do not comprehend the question.

They are often unaware of their deficits. Receptive aphasia

– Wernicke’s area contains memories of sequences of sounds that make up words

Difficulties in Wernicke’s AphasiaDifficulties in Wernicke’s Aphasia

Recognition:– Pure word deafness, the inability to

understand a word even when it is heard Comprehension:

– Transcortical sensory aphasia, damage to posterior language areas affects the ability to understand words even when recognized

Repetition:– Conduction aphasia, poor repetition even

when speech is fluent and meaningful

Other Regions in Wernicke’s Other Regions in Wernicke’s AphasiaAphasia Primary auditory cortex

– Interruption of delivery to Wernicke’s area– Damage causes pure word blindness

Posterior Language Area– Region located near the junction of the

temporal, occipital, and parietal lobes– Damage causes transcortical sensory aphasia

Arcuate Fasciculus– Axon passage between Wernicke’s area and

Broca’s area– Damage causes conduction aphasia

Aphasia SubtypesAphasia SubtypesSubtype Fluency Repetition Comprehension

Perisylvian: Broca’s (Motor)

- - +Transcortical: Motor - + +Perisylvian:

Wernicke’s (Sensory)+ - -

Transcortical: Sensory + + -Perisylvian: Conduction + - +Perisylvian: Global - - -Transcortical: Mixed - + -

From Lecture by Anthony Y. Stringer, Emory University , 2006

Voices of AphasiaVoices of Aphasia

Coloring DiagramsColoring Diagrams

RadioLab PodcastRadioLab Podcast

Words, Part 2

BrainstormingBrainstorming

What other factors affect our use of speech and language?

McGurk Effect ExperimentMcGurk Effect Experiment

Is Language Human Specific?Is Language Human Specific?

Do Animals Have Language?Do Animals Have Language?

Talking with Kanzi the Bonobo

Introduction to the Gorilla Foundation: Koko’s Sign Language

Goodbye to Alex the Parrot

Writing AssignmentWriting Assignment

What defines language?Is it unique to humans?

What experiments would you do to identify language correlates in animals?

Reading NeuroscienceReading Neuroscience

Speech SimilaritiesSpeech Similarities

The speech symptoms of people with aphasia tend to be mimicked in their reading symptoms.– Agrammatical speech—Agrammatical

writing– Patients with Broca’s aphasia

comprehend what they read, but have difficulty reading it aloud.

Pure AlexiaPure Alexia

Associated with visual cortex and posterior corpus callosum lesions

Maintain the ability to write, but not read

Perceptual disorder

Dear Dr. Warrington, Thank you for your letter of September 16th. I shall be pleased to be at your office between 10 & 10:30 am on Friday 17th October. I still find it very odd to be able to write this letter but not to be able to read it back a few minutes later. I much appreciate the opportunity to see you.

Yours sincerely,Harry X

Pathways in Pure AlexiaPathways in Pure Alexia Damage only to the left primary visual cortex

– Right visual field is blind; info from the left visual field passes to the right visual cortex

– Information passes to the extrastriate cortex, crosses over the corpus callosum

– Processed in left speech areas, making reading possible but difficult

Damage to the left visual cortex and corpus callosum– Patient cannot read: right visual field is blind, and

information from the left visual field cannot pass over the corpus callosum to the left speech areas

What about damage to the posterior corpus callosum?

HemialexiaHemialexia

Inability to read words that are located only in the left visual field

Words in the right visual field are read normally

DyslexiaDyslexia

Can be developmental or acquired Surface dyslexia

– Deficit in whole-word reading– Associated with damage to left lateral temporal

lobe– Errors are related to visual appearance, not

meaning Phonological dyslexia

– Deficit in sounding out words phonetically– Caused by damage to left frontal lobe

Other DyslexiasOther Dyslexias

Word-Form & Spelling Dyslexia– Inability to recognize or sound out words, but

able to read slowly

Direct Dyslexia– Cannot understand words that they are

reading aloud– For example, may read a word aloud correctly,

but cannot match the appropriate picture for the meaning of the word.

Writing DisordersWriting Disorders

Phonological Dysgraphia– Inability to write words phonetically

based on sounding them outOrthographic dysgraphia

– Ability to write words only when sounding them out

– Difficulty writing words that are not spelled the way they sound

Decoding Phonemes ExperimentDecoding Phonemes Experiment

Concept MappingConcept Mapping

Reading Disorders– Alexia– Dyslexia– Etc

How would you help people with these disorders learn to read?

Improving Your Language SkillsImproving Your Language Skills