1. Speech Production and Aphasia

2. Speech Production Includes a selection problem:
Select from possible words
Concept
Motor output

3. Brain Regions for Speech Production
Wernicke’s Area
Broca’s Area
Insula

4. Wernicke’s and Broca’s are densely interconnected
Connected by white-matter tract called the Arcuate Fasciculus
Catani et al. 2005

5. Aphasia
Much of what we know about language comprehension and production comes from lesion studies
Lesions anywhere in the network (including white matter) can result in complex language deficits

6. Aphasia Broca’s Aphasia Patient “Tan”
Classically thought of as a production deficit
But the sometimes make exclamations and swear !?
Note that Patient Tan’s lesion extended into the insula

7. Aphasia Wernicke’s Aphasia
Classically thought of as a comprehension deficit
But lesions to Wernicke’s area result in production deficits:
Non-sensical “word salad”

8. Aphasias are infamously complex
Why might the clinical picture of aphasia be complicated?