Copyright © 2008 Pearson Allyn & Bacon Inc.1 Chapter 13 Human Communication This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network preparation of any derivative work, including the extraction, in whole or in part, of any images any rental, lease or lending of the program.

Copyright © 2008 Pearson Allyn & Bacon Inc.2 Chapter 13 Outline Speech Production and Comprehension: Brain Mechanisms Disorders of Reading and Writing

Copyright © 2008 Pearson Allyn & Bacon Inc.3 Speech Production and Comprehension: Brain Mechanisms Lateralization Verbal behvaior is a lateralized function; most language disturbances occur after damage to the _____ side of the brain, whether people are left-handed or right-handed. If the left hemisphere is malformed or damaged early in life, then language dominance is very likely to pass to the right hemisphere. Left hemisphere is language dominant for 90% of all subjects: ___________________________________________ ___________________________________________ _________________________________________

Lateralization _______________________ Impairs the ability to read ____________, and recognize complex _______________________. Damage impairs the ability of subjects from talking about or understanding statements _____________________________________________. Damage impairs the expression and recognition of ______________________________. Copyright © 2008 Pearson Allyn & Bacon Inc.4

5 Speech Production and Comprehension: Brain Mechanisms Speech Production ___________________ Difficulty producing or comprehending speech not produced by deafness or a simple motor deficit; caused by brain damage. Broca’s aphasia A form of aphasia characterized by ______________________________________________ ______________________________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.6 Speech Production and Comprehension: Brain Mechanisms Speech production _______________ word(missing in Broca’s aphasia) A preposition, article, or other word that conveys little of the meaning of a sentence but is important in specifying its grammatical structure. (a, the, some, in, about) ______________ word(some can be produced with difficulty) A noun, verb, adjective, or adverb that conveys meaning. (apple, house, run) [telegraphic speech]

Copyright © 2008 Pearson Allyn & Bacon Inc.7 Speech Production and Comprehension: Brain Mechanisms Speech production Broca’s area A region of frontal cortex, located just rostral to the base of the left primary motor cortex, that is necessary for speech production. _______________________________________________ ______________________________________________ _____________________________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.8

9 Speech Production and Comprehension: Brain Mechanisms Speech production __________________ One of the usual symptoms of Broca’s aphasia; a difficulty in comprehending or properly employing grammatical devices, such as verb endings (-ed) and ________________. If asked to point to the picture “The horse kicks the cow”, they perform poorly. They omit grammatical markers, and do not understand them as well. They have motor and perceptual deficits involving grammar.

Copyright © 2008 Pearson Allyn & Bacon Inc.10 The only grammatical cue is word order

Copyright © 2008 Pearson Allyn & Bacon Inc.11 Speech Production and Comprehension: Brain Mechanisms Speech production ______________ Difficulty finding (remembering) the appropriate word to describe an object, action, or attribute; one of the symptoms of aphasia. _________________, unable to access them.

Copyright © 2008 Pearson Allyn & Bacon Inc.12 Speech Production and Comprehension: Brain Mechanisms Speech comprehension _______________________ A region of auditory association cortex on the left temporal lobe of humans, which is important in the comprehension of words and the production of meaningful speech.

Copyright © 2008 Pearson Allyn & Bacon Inc.13 Speech Production and Comprehension: Brain Mechanisms Speech comprehension Recognizing words ____________________________________________. Comprehending the meaning of words involves different brain mechanisms. After hearing a foreign word several times you learn to _____________________________________. Wernicke’s aphasia A form of aphasia characterized by poor speech comprehension and fluent but _______________ speech.

Copyright © 2008 Pearson Allyn & Bacon Inc.14 Speech Production and Comprehension: Brain Mechanisms Recognition: pure word deafness Pure word deafness The ability to hear, to speak and usually to read and write without being able to comprehend the meaning of speech; caused by damage to Wernicke’s area or disruption of auditory input to this region. (Fail a pointing task). Patients may be able to read and write, recognize emotions expressed by the intonation of speech, and recognize non-speech sounds like a door bell, or barking dog.

Copyright © 2008 Pearson Allyn & Bacon Inc.15 MRI of temporal lobe damage associated with pure word deafness.

Mirror Neurons Activated when performing and action, or seeing another subject perform it. Hearing words engages brain mechanisms that control __________________________________. Feedback from _____________________ may facilitate speech recognition. (Young children often move their lips when reading silently.) Copyright © 2008 Pearson Allyn & Bacon Inc.16

Copyright © 2008 Pearson Allyn & Bacon Inc.17 The excitability of tongue muscles increased when subject heard words that involved tongue movements (beer).

Copyright © 2008 Pearson Allyn & Bacon Inc.18 Speech Production and Comprehension: Brain Mechanisms Comprehension: transcortical sensory aphasia _________________________ (posterior language area) A speech disorder in which a person has difficulty comprehending speech and producing meaningful spontaneous speech but ______________; caused by damage to the region of the brain posterior to Wernicke’s area.

Copyright © 2008 Pearson Allyn & Bacon Inc.19 Posterior language area

Copyright © 2008 Pearson Allyn & Bacon Inc.20 Stimulation sites which when activated ‘mimic’ the loss of speech comprehension seen in transcortical aphasia. Subjects can repeat what they hear, but they do not comprehend speech.

Copyright © 2008 Pearson Allyn & Bacon Inc.21 Red arrows represent the translation of ________into words. Black arrows represent the _____________ of words.

Copyright © 2008 Pearson Allyn & Bacon Inc.22 Speech Production and Comprehension: Brain Mechanisms Comprehension: transcortical sensory aphasia ________________ (poor understanding of topography) Inability to name body parts or to identify body parts that another person names. Unable to point to their elbow, knee, or cheek.

Copyright © 2008 Pearson Allyn & Bacon Inc.23 Speech Production and Comprehension: Brain Mechanisms Repetition: conduction aphasia Arcuate fasciculus A bundle of axons that connects Wernicke’s area with Broca’s area; damage to these axons causes conduction aphasia. Subjects have fluent meaningful speech with good comprehension. They can only repeat speech sounds that have ____________. When they hear something meaningful it evokes ______________________________________________ __________________________. They are unable to repeat a string of unrelated words, or ________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.24 Lesions of arcuate fasiculus associated with conduction aphasia

Copyright © 2008 Pearson Allyn & Bacon Inc.25 Conduction aphasia: lesions disrupt the flow of auditory information (but not meaning) to the frontal lobe.

Copyright © 2008 Pearson Allyn & Bacon Inc.26 Computer generated model of arcuate fasciculus: damage to the red (deep & direct) pathway produces conduction aphasia.

Copyright © 2008 Pearson Allyn & Bacon Inc.27 Speech Production and Comprehension: Brain Mechanisms Memory of words: anomic aphasia _______________ A type of aphasia characterized by difficulty in finding __________. The speech of patients with anomia is fluent and grammatical, and their comprehension is excellent. Partial amnesia for words. Damage to different areas may result in amnesia for verbs and nouns respectively. ____________________ A strategy by which people with anomic aphasia find alternative ways to say something when they are unable to think of the ________________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.28 Speech Production and Comprehension: Brain Mechanisms Aphasia in deaf people Many deal people communicate via sign language. Sign language qualifies as a language. ________ language may have preceded vocal speech. The grammar of sign language is on it visual and spatial nature. The spatial nature of sign language suggest aphasic disorders in deaf people who use sign language might be caused by lesions of the right hemisphere. The reverse is true, ______________________________________________ ___________________________________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.29 Seeing and imitating finger movements used in ASL activate the left hemisphere.

Copyright © 2008 Pearson Allyn & Bacon Inc.30 Linkage between speech and hand movements: subjects produce _______ lip openings and greater vocal amplitudes when trained to say a syllable associated with watching an actor ______________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.31 Speech Production and Comprehension: Brain Mechanisms Prosody: rhythm, tone, and emphasis in speech ____________________________________ The use of changes in intonation and emphasis to convey meaning in speech besides that specified by the particular words; an important means of communication of_____________. Regulated by the _________hemisphere.

Copyright © 2008 Pearson Allyn & Bacon Inc.32 Prosodic elements activate the right hemisphere

Copyright © 2008 Pearson Allyn & Bacon Inc.33 Speech Production and Comprehension: Brain Mechanisms Stuttering Stuttering is a speech disorder characterized by frequent pauses, prolongations of sounds, or repetitions of sounds, syllables, or words that disrupt the normal flow of speech. Stuttering affects approximately 1 percent of he population and is three times more prevalent in ________________________________. Stutters have reduced auditory feedback produced by the ______________________. Delayed auditory feedback impairs the speech of normal subjects, but facilitates the speech of stutters.

Copyright © 2008 Pearson Allyn & Bacon Inc.34 Speech Production and Comprehension: Brain Mechanisms Stuttering Recent evidence suggests that stuttering is caused by abnormalities in regions of the brain that play a role in speech production. Stuttering is not a result of abnormalities in the neural circuits that contain the motor programs for speech. The problem appears to lie more in the neural mechanisms that are involved in the _________________________________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.35 Over activation of areas associated with stuttering The left temporal lobe appears to be the brain area that is over activated by stutters (Broca’s area and insula, regions involved articulation), and under-activation of auditory regions of the temporal lobe.

Stuttering May be due to faulty auditory feedback from sounds of the stutter’s voice to the auditory areas in the temporal lobe. Copyright © 2008 Pearson Allyn & Bacon Inc.36

Copyright © 2008 Pearson Allyn & Bacon Inc.37 After a successful course of therapy for stuttering the left temporal lobe shows increased activity. Delayed auditory feedback disrupts speech for non-stutters, but assists stutters.

Copyright © 2008 Pearson Allyn & Bacon Inc.38 Disorders of Reading and Writing Reading & speaking use some of the same brain areas. Most subjects with Wernicke’s aphasia have difficulty reading and writing, as well as understanding spoken speech. Pure alexia ______________(lesion in visual cortex in left hemisphere) Loss of the ability to read without the loss of the ability to_______; produced by brain damage. Also known as pure word blindness or alexia without agraphia.

Copyright © 2008 Pearson Allyn & Bacon Inc.39 “… I still find it very odd to be able to write this letter, but not be able to read it back a few minutes later”…

Copyright © 2008 Pearson Allyn & Bacon Inc.40 Pure alexia: a disruption in the flow of information to the left hemisphere extrastriate cortex. These subjects can recognize ________. Visual agnosia subjects can still ______, but not recognize objects.

Copyright © 2008 Pearson Allyn & Bacon Inc.41 Disorders of Reading and Writing Toward an understanding of reading: two different reading processes A. ____________________ Reading by recognizing a word as a whole; _______________. B. __________________ Reading by decoding the phonetic significance of letter strings; ________________.

Copyright © 2008 Pearson Allyn & Bacon Inc.42 A. B.

Copyright © 2008 Pearson Allyn & Bacon Inc.43 Disorders of Reading and Writing Toward an understanding of reading ____________________________________________ A reading disorder in which a person can read words phonetically but has difficulty reading irregularly spelled words by whole-word reading. ____________________________________________ A reading disorder in which a person can read familiar words but has difficulty reading unfamiliar words or pronounceable nonwords.

Copyright © 2008 Pearson Allyn & Bacon Inc.44 Surface Dyslexia

Copyright © 2008 Pearson Allyn & Bacon Inc.45 Phonological Dyslexia

Copyright © 2008 Pearson Allyn & Bacon Inc.46 Phonological reading, we sound words out by “feeling ourselves ________________ _______” via Broca’s area activation. Whole word reading Like reading a stop sign.

Copyright © 2008 Pearson Allyn & Bacon Inc.47 Disorders of Reading and Writing Toward an understanding of reading ________________ A language disorder caused by brain damage in which the person can read words aloud without _____________________. Unable to identify photos of the noun just read.

Copyright © 2008 Pearson Allyn & Bacon Inc.48 Disorders of Reading and Writing Toward an understanding of writing _______________________ A writing disorder in which the person cannot sound out words and write them phonologically. Damage to superior temporal lobe. ______________________ A writing disorder in which the person can spell regularly spelled words but not irregularly spelled ones. Damage to inferior parietal lobe.

Copyright © 2008 Pearson Allyn & Bacon Inc.49 Disorders of Reading and Writing Developmental dyslexias ____________________________ A reading difficulty in a person of normal intelligence and perceptual ability; of genetic origin or caused by prenatal or perinatal factors. Identical twins: % Fraternal twins: 20-35% Phonological impairments are common in many dyslexics. Dyslexia is rare in _________, and high in ________. In English __speech sounds can be spelled ____ different ways ( and __speech sounds can be spelled only __ different ways in Italian).

Summary The brain is a parallel processor: Left hemisphere judges the timing of ______ changing sound elements that convey word identity. Right hemisphere judges longer duration, _______ changing components of the air stream that convey the emotional status of the speaker. Listeners use both channels to assess the speaker’s intention, how they feel about what they are saying, and the truthfulness of the utterance. Copyright © 2008 Pearson Allyn & Bacon Inc.50