In addition to this, some Wernicke’s aphasics produce nonsense words—those are words that could be English, phonologically, but aren’t, such as, say, “fripple.” Some substitute a word that rhymes with the word they want, like “tire” for “fire.” Sometimes, they produce words that are semantically related to the word they want, like “banana” for “apple.”
One other interesting thing that this tells us about the brain is that words do not seem to be stored in a list, but rather, in neural networks or clusters. Imagine a network in which “pool” is stored in the brain close to “water,” “swim,” “dive,” “wet,” “blue,” and many others, yet the word also has a neural link to “tool,” “fool,” and “drool,” due to shared phonological properties. This concept is illustrated by the errors produced by patients who suffer from language loss. In fact, you may notice that it is illustrated by your own everyday slips-of-the-tongue, too! (2)
To wrap up the definition of Wernicke’s aphasia, here is a sample patient utterance, also documented by linguist Victoria Fromkin:
The only thing I can say again is madder or modder fish sudden fishing sewed into the accident to miss in the purdles. (2)
While we can’t make sense of this, notice how the sufferer uses function words like the infinitive “to” correctly, and includes a past tense ending on the verb “sew,” etc. This example also shows no hesitation, and finally, it illustrates some Wernicke-type nonsense words, like “modder,” and “purdles” (which may be a substitute for “puddles”).
Damage to the Language Areas of the Brain Reveals Facts about Grammar
In summary, because brain scans show damage to the areas that correspond to the types of aphasia that the patients suffer from, the contrast between these two types of aphasia shows us that not only is language (mostly!) lateralized to the left hemisphere, but also that major language components reside in distinct portions of the brain that are designated for them: One is linguistic grammar, meaning word order and function words, which is found in Broca’s area, and the other is linguistic meaning, meaning semantics and content words, which is found in Wernicke’s area.
By the way, this distinction between content and function is one that all languages have, and also, it is a distinction that linguists refer to as a “psychological reality.” That means that even people who have never heard of it may observe it unconsciously, and even joke about it. Here is a funny scene from The Office, in which Kevin drops the functional language from his speech. He says things like “stop worry!” in a futile and comical attempt to “save time.” Here is a funny scene from Friends, in which Phoebe and Rachel fight over who gets which alternating words on their outgoing voicemail message. They literally designate an expression for content words! They call them “the good words.” Phoebe gets mad because she is stuck with “it’s,” “a,” “and,” etc., while Rachel gets “Phoebe,” “Rachel,” “leave,” etc.