Power Point 16 aphasia

Aphasias: Language Disturbances Associated with Brain Injury The Classic View: based on symptoms and associated with particular brain areas The Major Syndromes: Broca’s aphasia Wernicke’s aphasia Conduction aphasia

Broca’s Aphasia Sparse halting speech Understanding relatively intact BUT cannot understand sentences like “The cow that was eating the apple was red” Most function words and inflections omitted Lesion Site: Posterior portion of left frontal lobe Cognitive Deficit: speech planning and production AND parsing

Sample of Speech for Broca’s Aphasia Attempting to describe when he had his stroke, which occurred when he was in a hot tub Alright…uh…stroke and un…I…h…hot tub and…And the…Two days when uh…Hos…uh…hospital and uh.. am…ambulance

Wernicke’s Aphasia Poor auditory comprehension Fluent speech but morphological and semantic errors Lesion Site: Posterior half of temporal cortex Cognitive Deficit Accessing lexemes for comprehension and production

Sample: Wernicke’s aphasia

Conduction Aphasia Relatively rare Disturbance of repetition (with awareness) Mild disturbance of spontaneous speech Lesion area: Arcuate fasciculus but more recent analysis questions this

Cognitive deficit: Disconnection of lexemes from speech production mechanisms

Cognitive Model Analysis of Speech Processing Pure word deafness Pure word meaning deafness Auditory phonological agnosia Deep dysphasis

Cognitive Model Analysis of Written Word Processing (Reading) Surface dyslexia Phonological dyslexia Deep dyslexia

Cognitive Model Analysis of Auditory Speech Processing Pure word deafness can talk & read fluently can’t repeat words they can’t understand can’t understand speech addressed to them Impairment = phonemic processing in the auditory analysis system

Pure Word Meaning Deafness Can’t understand what words mean when spoken Can repeat words Can write words from dictation Can decide what is really a word Impairment = connection between the auditory lexicon & semantic system

Auditory Phonological Agnosia Can read aloud & write well Can’t repeat non-words or words not heard before

Impairment = direct route for repetition via auditory analysis system

Deep Dysphasia Can’t repeat non-words Makes semantic errors when repeating back real words

Impairment = access to semantics from auditory input lexicon & direct route from auditory analysis system

Cognitive Model Analysis of Processing Written Speech Surface Dyslexia Able to read words if they are regular in their spelling Can read non-words Impairment = Visual input lexicon

Case: William

Phonological Dyslexia Can read familiar words Has difficulty with non-words & novel words

Impairment = grapheme-phoneme conversion

Case: Ann

Deep Dyslexia Semantic errors