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Ling 411 – 05. Types of Aphasia. Simple Functions / Complex Functions: Speaking and Understanding. How is simplicity/complexity determined? What about "understanding speech“? A simple process, localized in Wernicke's area? Actually it is a pretty complex process - PowerPoint PPT Presentation
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Types of Aphasia
Ling 411 – 05
Simple Functions / Complex Functions: Speaking and Understanding
• How is simplicity/complexity determined?
• What about "understanding speech“? • A simple process, localized in Wernicke's area? • Actually it is a pretty complex process
• Similarly, “speaking”• Pretty complex, not just Broca's area• Uses not just Broca’s area but also Wernicke’s area• Without a properly functioning Wernicke’s area, speech is erratic
Simple Functions / Complex Functions
Simple function
Complex function
Simple Functions / Complex Functions
Speaking vs. Phonological Production• Phonological production is one part of speaking
– located in Broca’s area• Speaking is a complex process
Phonological production plus planning what is about to be produced – involves Wernicke’s area
Understanding speech vs. phonological recognition• Phonological recognition is one part of speech
understanding – located in Wernicke’s area• Speech understanding is a complex process
Includes grammatical and semantic activity Motor activity (Broca’s area) also contributes
Basic functions and complex functions – speaking
Phonological recognition is a basic function Located in Wernicke’s area
• along with, perhaps, the area intermediate between primary auditory area and W’s area
Speaking is a complex function• It is a cooperative effort of several areas,
including Broca’s area and Wernicke’s area• Phonological recognition is a necessary
component of speaking
Major Types of Aphasia according to A. Damasio
Wernicke’s aphasia Broca’s aphasia Transcortical sensory aphasia Transcortical motor aphasia Conduction aphasia Global aphasia Anomic aphasia Alexia with agraphia Alexia without agraphia Pure word deafness
Wernicke’s Aphasia
Impaired comprehension• Result of failures in phonological discrimination
Fluent verbal output Augmented verbal output
• Extra syllables at ends of words• Extra words at ends of phrases• Extra phrases at ends of sentences
Augmentations usually nonsensical Syntax otherwise not too bad Verbal paraphasia, including neologisms
Areas of damage in Wernicke’s aphasia
Always involved:• Posterior superior temporal gyrus
The classical core of Wernicke’s area Usually also involved:
• More of superior temporal gyrus• Middle temporal gyrus• Temporal plane*
Often also involved:• Angular gyrus• Supramarginal gyrus• Temporal-occipital junction area
*can be considered part of superior temporal gyrus
Definitions of Wernicke’s area
1. Narrow definition Posterior superior temporal gyrus Including adjacent temporal plane
and superior temporal sulcus
2. Broad definition (used by some)• Includes also angular gyrus and/or
supramarginal gyrus• Better term for this broader area:
‘Posterior language area’
Principal cortical gyri (schematic)Review
Subtypes of Wernicke aphasia
Not discretely different• Rather, spans along a scale
Type I• Damage is more anterior• Phonological recognition most affected• “Word deafness”
Type II• Damage is more posterior, incl. angular gyrus• More word-blindness than word-deafness
I.e., alexia Intermediate types also occur “Obviously, all subtypes of Wernicke aphasia are
variations on a continuum…” •
(Benson&Ardila:144)
Wernicke’s Aphasia examples
http://www.youtube.com/watch?v=B-LD5jzXpLE&feature=related http://www.youtube.com/watch?v=aVhYN7NTIKU
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