Brain Anatomy

Language is primarily processed in the left hemisphere. The two main language- processing centers, Wernicke's area and Broca's area, both lie on the left side of the brain, as pictured below. Wernicke's area lies in the left temporal lobe near the primary auditory cortex, and is responsible for analyzing spoken language. Damage to Wernicke's area causes Wernicke's aphasia, a condition in which people can hear language being spoken, but cannot understand it. Broca's area lies in the left frontal lobe, near the primary motor cortex, and is responsible for producing coherent speech. Damage to Broca's area causes Broca's aphasia, a condition in which people have trouble producing grammatical language. However, this division between comprehension and production is not as neat as it seems. Wernicke's aphasia also causes some difficulties in production; people with this condition produce sentences that are grammatically correct but contain no meaningful content. Also, people with Broca's aphasia have trouble understanding sentences with complex grammatical construction. One theory of language production holds that Wernicke's area is responsible for individual words, while Broca's area is responsible for grammar.