Aphasia is essentially a term used to describe any language impairment. Aphasias can be expressive in nature, like in the case of Broca's, but sensory aphasias are also commonly encountered. A sensory aphasia causes individuals to no longer understand the meaning of language and is often due to neurological damage in a specific brain region known as Wernicke’s area.
A contemporary of Broca, a German physician named Carl Wernicke (pronounced Vern-nick-key), was also interested in how brain disease affects speech and language. His research identified the specific area of the brain responsible for processing the meaning of language, an area now known as Wernicke’s area. While patients with Wernicke’s aphasia do not lose the ability to speak, they do lose the ability to understand the meaning of language. A Wernicke's aphasiac will babble unintelligibly, and speak using a jumble of meaningless phrases, described as a “word salad”. An example of Wernicke's aphasia can be seen here.
It is doubtful that you would be unaware of having an aphasia as symptoms are obvious and include:
- inability to pronounce words, not due to muscle paralysis or weakness
- inability to name objects
- poor enunciation
- inability to repeat a phrase
- persistent repetition of phrases
- agrammatism (inability to speak in a grammatically correct fashion)
- dysprosody (alterations in inflexion, stress, and rhythm)
- speaking in incomplete sentences
- inability to read
- inability to write
*Noam Chomsky's famous example of a word salad. It demonstrates that randomly chosen words that while arranged in a phrase that appears to give them meaning, actually carry no significance.