Wernicke's aphasia results from damage to which cortical area, and what is the hallmark deficit?

• A. Left superior temporal gyrus (posterior language area); fluent but impoverished speech with impaired comprehension.
• B. Left inferior frontal gyrus; nonfluent speech with relatively preserved comprehension.
• C. Left posterior superior temporal gyrus; fluent speech with impaired comprehension.
• D. Right inferior parietal lobule; poor repetition

Answer: (C)

Wernicke's aphasia is produced by damage to the left posterior superior temporal gyrus, a region that processes spoken language and maps sounds onto meaning. When this area is injured, speech tends to be fluent and well rhythmically formed, but the content is often meaningless or filled with incorrect or invented words. The person cannot understand spoken language well, so comprehension is severely impaired, and repetition is typically poor because the sounds they hear aren’t being translated into correct meanings. This combination—fluent but nonsensical speech plus impaired comprehension—best matches the described pattern.

Damage to the left inferior frontal gyrus, by contrast, leads to nonfluent, effortful speech with relatively preserved comprehension. The right hemisphere areas are less typically involved in this pattern of language, and poor repetition alone is not characteristic of Wernicke's aphasia.