Notes: Exam corrections – due on Thursday, November 12 Last Exam Concrete vs Abstract words
Dec 21, 2015
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
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:
Mapping Speech Zones
Confirm roles of anterior / posterior speech zones
Posterior speech zone: analysis of auditory input
Additional role for Broca’s areaLanguage 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
Fluent Aphasias:
Wernicke’s (Sensory) AphasiaTranscortical mixed Aphasia (isolation
syndrome)Conduction AphasiaAnomic or Amnesic Aphasia
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 GangliaImportant for speech articulation
ThalamusInfluences language by activating the cortex