Higher Mental Functions of the Brain: Language

The dominant hemisphere, typically the left hemisphere, is responsible for understanding language and generating speech. It interprets the meaning of spoken, written, or sign language and enables communication. The right hemisphere complements this by adding tone and emotional context to spoken words, creating complete linguistic expression.

Wernicke's area, the language comprehension center, is located in the left temporal lobe. It interprets the meaning of spoken and written language by receiving input from the auditory association area for spoken words or the visual association area for written language and gestures. Damage to this area causes receptive aphasia, impairing language understanding.

Broca's area, located in the left frontal lobe, is the speech production center. It develops a motor pattern that is conveyed to the primary motor area to activate muscles necessary for producing words. Injury to Broca's area results in expressive aphasia, hindering the ability to speak and form words despite understanding language.

When hearing a word, the auditory association area sends information to Wernicke's area, which translates it into meaning. Wernicke's area then transmits this information to Broca's area, which develops a motor pattern. This pattern travels to the primary motor area, triggering coordinated muscle contractions that allow you to speak the word.

Written language follows a different sensory pathway than spoken language. For written words, the primary visual area sends information to Wernicke's area, whereas spoken language reaches Wernicke's area through the primary auditory area. Despite these different input routes, both pathways converge at Wernicke's area for language comprehension and subsequent speech production.

Receptive aphasia is difficulty understanding spoken or written words, caused by damage to Wernicke's area. Individuals with this condition struggle to comprehend language despite intact speech production abilities. This contrasts with expressive aphasia, which results from Broca's area damage and impairs the ability to produce speech while maintaining comprehension.

The left hemisphere handles language formation and comprehension through Wernicke's and Broca's areas, while the right hemisphere adds emotional tone and context to spoken words. This hemispheric specialization allows for complete linguistic communication that conveys both literal meaning and emotional nuance, supporting higher mental functions of the brain.