http www youtube comwatch vf 2 Ii MEb

http: //www. youtube. com/watch? v=f 2 Ii MEb. Mn. PM&feature=youtu. be Neuroscience: Exploring the Brain, 3 e Chapter 20: Language http: //youtu. be/67 HMx-Td. AZI http: //youtu. be/f 2 Ii. MEb. Mn. PM http: //youtu. be/NUTpel 04 Nkc http: //youtu. be/a. Vh. YN 7 NTIKU Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Introduction • Language – System by which sounds, symbols, and gestures used for communication – Process • Language comes into brain through visual and auditory systems • Motor system: Produces speech, writing, signaling • Processing between sensory and motor systems; Essence of language • Aphasia – Partial/complete loss of language abilities following brain damage, mutations (FOXP 2 gene) Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

The Discovery of Specialized Language Areas in the Brain • Broca’s Area and Wernicke’s Area – Broca’s area (Paul Broca 1864: Region of dominant left frontal lobe, articulate speech – Wernicke’s area (Karl Wernicke 1874): Superior surface of temporal lobe between auditory cortex and angular gyrus, lesions disrupt normal speech Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

The Discovery of Specialized Language Areas in the Brain • Wada Procedure – Used

The Discovery of Specialized Language Areas in the Brain • Broca’s Aphasia (motor, nonfluent aphasia) – Difficulty speaking (fragmented speech), but understand spoken/heard language – Paraphasic errors – Pause to search for words, repeat “overlearned” things, difficulty repeating words after hearing them http: //youtu. be/f 2 Ii. MEb. Mn. PM http: //www. youtube. com/watch? v= NUTpel 04 Nkc&feature=youtu. be Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

http: //youtu. be/f 2 Ii. MEb. Mn. PM

Norman Geschwind interview http: //www. youtube. com/watch? v= NUTpel 04 Nkc&feature=youtu. be

The Discovery of Specialized Language Areas in the Brain • Wernicke’s aphasia, fluent speech, poor comprehension • Strange mixture of clarity and gibberish • Correct sounds, incorrect sequence (sentences don’t make sense) • Comprehension difficult to assess • Playing music, writing similarly fragmented – Storing memories of sounds that make up words – Symptoms: Mixture of clarity and gibberish, undisturbed by sound of own or other’s speech – Characteristics: Correct words in incorrect sequence, incorrect word similar to correct word http: //www. youtube. com/watch? v= 67 HMx-Td. AZI&feature=youtu. be a. Vh. YN 7 NTIKU&feature=youtu. be http: //youtu. be/a. Vh. YN 7 NTIKU Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

http: //www. youtube. com/watch? v= 67 HMx-Td. AZI&feature=youtu. be

The Discovery of Specialized Language Areas in the Brain • Wernicke-Geschwind Model – Broca’s area – Wernicke’s area – Arcuate Fasciculus (connects them) – Angular gyrus – Problems with model: comprehension and production deficits with both types of aphasia Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

The Discovery of Specialized Language Areas in the Brain • Conduction Aphasia – Lesion of fibers composing arcuate fasciculus – Comparison with Broca’s aphasia, Wernicke’s aphasia: Comprehension good, speech fluent – Difficulty repeating words – Symptoms: Repetition substitutes/omits words, paraphasic errors, cannot repeat function, nonsense words, polysyllabic words Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

The Discovery of Specialized Language Areas in the Brain • Aphasia in Bilinguals and the Deaf – Aphasia in bilinguals- Language affected depends on: Order, fluency, use of language – Sign language aphasias analagous to speech aphasias but can be produced by lesions in slightly different locations – Verbal and sign language recovered together in one case indicating overlapping regions used for both – Evidence suggests some universality to language processing in the brain Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Asymmetrical Language Processing in the Cerebral Hemispheres • Split-Brain Studies – Roger Sperry (1950 s) – Split-brain procedure • Sever axons making up the corpus callosum • No major deficits • With proper experiments, animals behaved as if they had 2 brains Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Asymmetrical Language Processing in the Cerebral Hemispheres • Language Processing in Split-Brain Humans – Gazzaniga: Brief stimuli delivered only to one hemisphere – Observation: Two hemispheres initiated conflicting behaviors http: //youtu. be/ZMLz. P 1 VCANo http: //youtu. be/zx 53 Zj 7 EKQE Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

http: //youtu. be/ZMLz. P 1 VCANo

http: //youtu. be/zx 53 Zj 7 EKQE

Asymmetrical Language Processing in the Cerebral Hemispheres • Left Hemisphere Language Dominance – Right visual field, repeated easily – Left visual field, difficulty verbalizing – Image only in left visual field, object in left hand, unable to describe – Split-brain • Unable to describe anything to left of visual fixation point Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Asymmetrical Language Processing in the Cerebral Hemispheres • Language Functions of the Right Hemisphere – Functions of right hemisphere: Read and understand numbers, letters, and short words (nonverbal response) – Baynes, Gazzaniga, and colleagues: Right hemisphere able to write, cannot speak – Right hemisphere: Drawing, puzzles, sound nuances – Left hemisphere: Language Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Asymmetrical Language Processing in the Cerebral Hemispheres • Anatomical Asymmetry and Language – Left lateral (Sylvian) fissure longer and less steep than right – Geschwind and Levitsky: Left planum temporal larger than right in 65% cases – Functional human asymmetry: More than 90% humans right-handed – Animals: Equal numbers of righthanders and left-handers Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Language Studies Using Brain Stimulation and Brain Imaging • Language Studies – Old methods: Correlate language deficits with postmortem analysis of brain damage – Recent techniques • Study language function in brains of living humans: Electrical brain stimulation and PET • The Effects of Brain Stimulation on Language – Three main effects: Vocalizations, speech arrest, speech difficulties similar to aphasia Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Language Studies Using Brain Stimulation and Brain Imaging • The Effects of Brain Stimulation on Language (Cont’d) – Motor cortex: Immediate speech arrest – Broca’s area: Speech stopped after strong stimulation, speech hesitation from weak stimulation – Posterior parietal lobe near Sylvian fissure and temporal lobe: Word confusion and speech arrest – George Ojemann: Stimulate small parts of cortex: naming, reading, repeating facial movements Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Language Studies Using Brain Stimulation and Brain Imaging • The Effects of Brain Stimulation on Language (Cont’d) Jargon Arrested speech Naming difficulty Facial movement errors Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Language Studies Using Brain Stimulation and Brain Imaging • Imaging of Language Processing in the Human Brain – f. MRI (Lehericy and colleagues): Record during 3 different language tasks • Activated brain areas consistent with temporal and parietal language areas • More activity than expected in nondominant hemisphere a) Word production b) Silent sentence repetition c) Passive listening Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Language Studies Using Brain Stimulation and Brain Imaging • PET imaging of sensation and

Language Studies Using Brain Stimulation and Brain Imaging • Language Acquisition – Mechanism in infants: innate phoneme-pair recognition • Syllable emphasis • Motherese • Adults talk to infants; Speech slower, exaggerated, vowel sounds clearly articulated http: //youtu. be/WXWGnryj. Ea. Y http: //youtu. be/Ew 5 -xbc 1 HMk Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Language Studies Using Brain Stimulation and Brain Imaging • Dehaene-Lambertz: 3 -month infant, brain response to spoken words similar to adults – f. MRI of 3 -month-old infant shows response to spoken words similar to that in adults q Songbirds: Model system for studying mechanisms of vocal learning Song learning similar to speech learning in humans Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Concluding Remarks • Repeating a word that is read: Initial activity in visual cortex, then activity in motor cortex corresponding to muscles that move vocal apparatus • Multiple brain areas critical for language, not just Broca’s and Wernicke’s areas • Hemispheric differences • Brain imaging studies expected to reveal more about language system organization Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

End of Presentation Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins

Song learning: Nature of long-term sensory memories used for vocal learning.

Tutor models:

Songs of birds tutored with forward-ordered phrase pairs (DE, CD, BC, AB)

Songs of birds tutored with reversed-order phrase pairs (BA, CB, DC, ED)

The Discovery of Specialized Language Areas in the Brain • Aphasia – Partial/complete loss of language abilities following brain damage – Greek/Roman Empires: Tongue controls speech – Sixteenth century: Speech impairment, tongue not affected – 1770: Johann Gesner, brain damage – 1825: Jean-Baptist Bouillard, frontal lobes – 1861: Cortical area in frontal lobe Copyright © 2007 Wolters Kluwer Health | Lippincott Williams & Wilkins