Wernicke's
Summary
Wernicke's area is a region of the posterior temporal lobe, in the left hemisphere for most people, that supports language comprehension. Damage causes Wernicke's aphasia: fluent but meaningless speech with poor comprehension, unlike Broca's aphasia (halting speech, comprehension largely intact).
Detail
Meaning: Wernicke's area lies in the posterior superior temporal gyrus, usually in the left hemisphere, and is central to understanding spoken and written language. Damage causes Wernicke's (receptive) aphasia: speech is fluent and well paced but often meaningless, with wrong or invented words, and comprehension is poor. Patients are often unaware of their errors.
On the MCAT: A passage describes a patient with a lesion and asks which area is affected. Fluent but nonsensical speech with poor comprehension points to Wernicke's. Effortful, halting speech with good comprehension points to Broca's area in the frontal lobe. In the classic Wernicke-Geschwind model, a heard word is processed in auditory cortex, interpreted in Wernicke's area, then sent through the arcuate fasciculus to Broca's area for speech production. Damage to that tract classically causes conduction aphasia: poor repetition despite fairly good comprehension and fluency.
Common confusion: Fluent does not mean meaningful. Students link Wernicke's with a speech problem, but its core deficit is comprehension; Broca's is the production problem. Also, the temporal lobe holds Wernicke's and the frontal lobe holds Broca's. Language is left-lateralized in most people, not in everyone.
Sources
- Psychology
- Biological Psychology
Written for the MCAT and checked before it was published. For study reference only. Spotted an error? Let us know.