Week 9 (Language in the brain) Flashcards
What is aphasia?
Disorders of speaking and listening, caused by stroke, tumour or head injury.
Where is the Broca’s area
In the left frontal lobe
Broca’s aphasia
-AKA “expressive” or “nonfluent” aphasia
-slow, deliberate, effortful speech production
-non-fluent
-Agrammatism in comprehension
-but comprehension is otherwise generally preserved
-Aware of their language deficit
Wernicke’s aphasia
-AKA “fluent” or “receptive” aphasia
-Fluent, but often content-free
-Function words often used appropriately, but many content words (nouns, verbs) missing, some replaced by neologisms (non-words)
-Severe comprehension deficits
-Generally unaware of their language deficit.
What is paraphasia
Type of language output error commonly associated with aphasia.
The types of paraphasia
-Phonemic paraphasia: “pike”/ pipe
-Neologistic paraphasia “pin wad”/ light
-Semantic paraphasia “wife”/ husband
-Preservative paraphasia: previous responses persist and interfere with retrieval/ production.
What does the Wernickes area do?
Decodes sounds for meaning
What does the Broca’s area do?
Activates speech plan, grammar.
What is the Wernicke-Geschwind model?
Neural circuitry that turns:
-Speech sounds into thoughts
-Thoughts into mouth and tongue movements.
What connects the Broca’s and Wernicke’s area?
Arcuate fasciculus
Lesion of arcuate fasciculus
Disrupts transfer from WA to BA: difficulty in repeating words but spoken comprehension and ability to speak spontaneously may be ok.
Lesion of angular gyrus
Disrupts flow from visual cortex = disrupts saying words seen but not words heard.
Global Aphasia
-Most severe form of aphasia
-Can produce few recognisable words (if any) and understand little or no spoken language
-Verbal stereotypy: repeat a sound/ phrase over and over in attempt to communicate
-Can no longer read or write
-Preserved intellectual and cognitive capabilities unrelated to language and speech/
What part of the brain is damaged to cause global aphasia.
Left perisylvian cortex
What is apraxia of speech?
-Difficulty initiating and executing voluntary movement patterns necessary to produce speech despite normal muscle stuff.
-Slowed speech, abnormal prosody, distortions of speech sounds
-Specific neural basis unclear
