Wernicke's area

Meaning: Wernicke's area lies in the posterior superior temporal gyrus, in the left hemisphere in most people. It supports language comprehension. In the classic model, heard words are processed in auditory cortex, interpreted in Wernicke's area, and relayed along a fiber bundle called the arcuate fasciculus to Broca's area in the frontal lobe, which plans speech production.

On the MCAT: A passage describes a patient with a lesion or a imaging result and asks which deficit follows. Damage to Wernicke's area produces receptive (fluent) aphasia: speech has normal rhythm and grammar-like flow but contains wrong or invented words, and the patient has trouble understanding others. Damage to Broca's area produces nonfluent, effortful speech with comprehension relatively preserved. Damage to the arcuate fasciculus produces conduction aphasia: comprehension and fluency are relatively preserved, but repeating spoken phrases is poor. Questions may also ask for location: temporal lobe for Wernicke, frontal lobe for Broca.

Common confusion: Students swap the two areas. Ask two questions: does the patient understand, and is speech fluent? Poor understanding with fluent, empty speech points to Wernicke. Good understanding with halting, telegraphic speech points to Broca. The classic model is a simplification, since language relies on a wider network, but the exam uses the classic localization.