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Notes: Exam corrections – due on Thursday, November 12 Last Exam Concrete vs Abstract words. “ Language ”. Human Neuropsychology (486 / 686) Lecture Chapter 19. 2. Components of Language. The Production of Sound. Origins of Language.
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Notes: Exam corrections – due on Thursday, November 12 Last Exam Concrete vs Abstract words
“Language” . Human Neuropsychology (486 / 686) Lecture Chapter 19 2
Origins of Language • Vocalization theories - precursors of language were animal vocalization. (poo-poo, bow-wow, yo-he-ho, sing-song) • Gestural Theory – Primitive gestures evolved into language • Multimodal Theory – gestures and vocalizations evolved together
A Theory of Language • Core skills for language: 1. Categorization 2. Label categories 3. Sequence behaviors 4. Mimicry
The Localization of Language Anatomical Areas : pSTP aSTP
Localization of Language • WernickeGeshwind Model Primary auditory Visual areas parietal
Mapping Speech Zones: • Electrical stimulation – generally confirms roles of classic speech areas, adds primary motor and somatosensory areas and supplimental motor area (prefrontal) • Transcranial Magnetic Stimulation (TMS) – generally confirms electrical stimulation studies but suggests additional role for Broca’s area • Imaging – fMRI: many areas activated • PET: specific areas active for specific tasks
Mapping Speech Zones • Confirm roles of anterior / posterior speech zones • Posterior speech zone: analysis of auditory input • Additional role for Broca’s area • Language maps onto primary sensory areas
Disorders of Language • Aphasia - Disorder of speaking, writing (agraphia), or reading (alexia) that does not result from loss of sensory input, muscle paralysis or intellectual impairment
Why is studying language complex? • 1. Widespread areas of the brain contribute to language • 2. Most studies of language disorders involve patients with damage to the Middle Cerebral Artery • 3. Language deficits after a stroke are severe at first, but recover over time • 4. Aphasias have many symptoms and causes
Disorders of Language • Three Main Categories of Aphasia
Fluent Aphasias: • Wernicke’s (Sensory) Aphasia • Transcortical mixed Aphasia (isolation syndrome) • Conduction Aphasia • Anomic or Amnesic Aphasia
Nonfluent Aphasias • Broca’sor Expressive aphasia • Transcortical Motor Aphasia, • Global Aphasias
Cortical Components Fluent Aphasias: Core deficit is Lack of speech comprehension - temporal regions around Wernicke’s Non-fluent Aphasias: Five symptoms – • 1. Speech Apraxia - insula • 2. Sentence comprehension • - superior temporal gyrus • 3. Speech repetition - arcuate fasciculus • 4. Working memory • 5. Articulation Broca’s area
Pure Aphasias • Alexia - Inability to read (left temporooccipital) • Agraphia - Inability to write (left inferior parietal) • Word deafness - Cannot “hear” or repeat words (superior temporal gyrus)
Subcortical Components of Language • Basal Ganglia • Important for speech articulation • Thalamus • Influences language by activating the cortex