Language & Speech June 21, 2011

Review 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.

Discussion What is Language? Why Do We Use Speech & Language? Are Speech & Language Unique to Humans?

Create Your Own Language

RadioLab Podcast Words, Part 1

Wernicke’s & Broca’s Area

Language 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 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: Case J.M. 16 y.o. white female 8 th 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

J.M.’s Brain Scan

Normal Angiogram of J.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 Angiograms

Boston Diagnostic Aphasia Exam Repetition Fluency Word Discrimination Complex Comprehension Responsive Naming Confrontation Naming Reading %ile Kaplan Sentence Arrangement Test60% From Lecture by Anthony Y. Stringer, Emory University, 2006 J.M.’s Language Results

Right 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 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

Role 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 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 Aphasia 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 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

How Does Wernicke’s Aphasia 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 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 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 Aphasia 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 Subtypes SubtypeFluencyRepetitionComprehension 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 Aphasia

Coloring Diagrams

RadioLab Podcast Words, Part 2

Brainstorming What other factors affect our use of speech and language?

McGurk Effect Experiment

Is Language Human Specific?

Do Animals Have Language? Talking with Kanzi the Bonobo Introduction to the Gorilla Foundation: Koko’s Sign Language Goodbye to Alex the Parrot

Writing Assignment What defines language? Is it unique to humans? What experiments would you do to identify language correlates in animals?

Reading Neuroscience

Speech 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 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 16 th. I shall be pleased to be at your office between 10 & 10:30 am on Friday 17 th 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 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?

Hemialexia Inability to read words that are located only in the left visual field Words in the right visual field are read normally

Dyslexia 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 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 Disorders Phonological Dysgraphia –Inability to write words phonetically based on sounding them out Orthographic dysgraphia –Ability to write words only when sounding them out –Difficulty writing words that are not spelled the way they sound

Decoding Phonemes Experiment

Concept Mapping Reading Disorders –Alexia –Dyslexia –Etc How would you help people with these disorders learn to read?

Improving Your Language Skills