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Neurological Basis for Speech and Language. MCB 163: Mammalian Neuroanatomy 01 December, 2005. Bradley Voytek. Helen Wills Neuroscience Institute University of California – Berkeley. btvoytek@berkeley.edu http://socrates.berkeley.edu/~btvoytek. Aphasia. Patient “Tan” (Leborgne)
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Neurological Basis for Speech and Language MCB 163: Mammalian Neuroanatomy 01 December, 2005 Bradley Voytek Helen Wills Neuroscience Institute University of California – Berkeley btvoytek@berkeley.edu http://socrates.berkeley.edu/~btvoytek
Aphasia Patient “Tan” (Leborgne) • Could answer questions with gestures • Could say a few curse words, “tan” • Broca hoped to disprove cortical specialty • In autopsy, found an abscess in Tan’s brain • 1865 paper showed localization to left frontal lobe (Broca’s area) Pierre Paul Broca
Aphasia Another region? • Not all language disturbances were speech • Not all disturbances involved Broca’s area • Loss of words comprehension • 1874 paper showed localization to left temporal lobe (Wernicke’s area) Carl Wernicke
Speech & Language Regions • Broca’s (BA 44, 45): Inf prefrontal gyrus • Wernicke’s (BA 22): Post sup temporal gyrus at the T-P junction • Arcuate fasciculus: Axon tract connecting Broca’s with Wernicke’s
Types of Disorders • Broca’s & expressive aphasias • Wernicke’s & receptive aphasias • Transcortical motor aphasia • Transcortical sensory aphasia • Conduction aphasia • Global aphasia • Subcortical aphasia • Anomia • Alexia • Apraxia
Broca’s Aphasia Nature • True Broca’s aphasia manifests with damage to several areas including: • Broca’s area • Left insula • Left arcuate fasciculus Symptoms • Loss of fluency and articulation • Inability to repeat complex sentences • Impaired comprehension of complex sentences
Broca’s Aphasia MRI Video Patient Video • Did you notice his right arm and hand?
Broca’s Aphasia Anterior insula
Broca’s Aphasia (2005) Anterior insula & arcuate fasciculus
Fluent aphasia • Wernike’s aphasia • Nonsensible speech • Not able to comprehend others speech • Damage to unimodal association cortex in area 22 • Superior temporal gyrus
Nonfluent aphasia • Broca’s aphasia • Agrammatic • Telegraphic speech • Difficulty using the words: but, if, or, to , from
Paraphasia Often a feature of other aphasias Neologistic • Invention of new words: • ‘glipt’ or ‘crint’ Semantic • Word substitution, similar meaning: • ‘knife’ for ‘spoon’ Phonemic • Sound substitution: • ‘scoon’ for ‘spoon’
Global Aphasia • Damage so widespread is usually caused by MCA infarct