Wernicke’s area is the region in the brain that is responsible for language comprehension. This region contributes largely to the overall comprehension of language. In the latter paragraphs, the discovery, the functions, other brain regions that are associated with Wernicke’s area, diseases affecting language, and methods to detect a language compromising and vocalization disease will be discussed.
A German neurosurgeon, Carl Wernicke, discovered the area of the brain in the posterior portion of the left temporal lobe that is responsible for understanding language. His hypothesis was tested with patients that had a lesion in that particular part of the brain. The patients with a healthy Wernicke’s area were able to properly speak and understand spoken and written language. The patients that had trauma to Wernicke’s area (Wernicke’s aphasia) were not able to speak coherently. Wernicke’s findings are still valued today as the modern explanation for language comprehension.
Wernicke’s area has a main function of allowing language comprehension, recognition, interpretation, and processing to take place. When language is heard via auditory stimulation, the stimuli goes to the primary auditory cortex, where its then sent to Wernicke’s area to be processed and associated into a word with a meaning via memories. The same process is achieved when language is read out loud from a visual stimulus. The initial stimulus goes to the primary visual cortex, where it is then transferred to the angular gyrus where it is organized into language and thoughts. The stimulus is then transferred to the Wernicke’s area to be associated with a particular meaning.
Wernicke’s area is associated with several other brain regions. A visual stimulus of language is sent to the angular gyrus before it is sent to Wernicke’s area. This is the region where perceived words are associated with different images and ideas. Wernicke’s area is located in the left temporal lobe, posterior to the primary auditory complex (Brookheimer 2000). Wernicke’s area is closely associated with Broca’s area and is therefore connected it by a large bundle of neuron fibers called arcuate fasciculus. Broca’s area is responsible for language production. These three brain regions are collectively responsible for language processing. The neural loop that these regions create allows language to be spoken, understood, recognized, interpreted, and processed (Brookheimer 2000).
Many diseases can affect language including Alzheimer’s disease, progressive non fluent aphasia, corticobasal degeneration, and semantic dementia. Alzheimer’s disease affects the medial temporal lobes and eventually the superior parietal lobes. Progressive non fluent aphasia is degeneration of Broca’s area in the left hemisphere of the brain (Hillis 2001). Corticobasal degeneration affects the cortical regions that are responsible for language. Semantic dementia affects the temporal lobes of the brain.
In addition to the prior mentioned diseases that affect language, Wernicke’s aphasia also affects language. Wernicke’s aphasia is characterized by impaired ability to remember the names of objects and impaired language comprehension and is caused by cell death in the posterior superior areas of the temporal lobe. A patient with Wernicke’s aphasia speaks incoherently because of the lack of their ability to understand spoken language due to the aphasia. This can be caused by a stroke that blocks blood supply to Wernicke’s area, resulting of cell death in that region. This type of aphasia can sometimes be classified as fluent aphasia when the patient is still able to speak smoothly (Hillis 2001). Information is heard through the auditory cortex, yet when it reaches the posterior superior areas of the temporal lobe (Wernicke’s area), the information cannot be translated into meaningful words. Thus, the patient is still able to speak fluently, but incoherently. These symptoms differ from Broca’s aphasia in the sense that those patients’ language is no longer fluent. Broca’s aphasia causes difficulty with repetition and a severe impairment in writing. If there is damage to both Wernicke’s area and Broca’s area, global aphasia can occur (Coslett 1984). Global aphasia affects all areas of speech. Patients with this condition are only able to speak a few words. They cannot read, write, or repeat words.
There are several methods that are used to detect damage or ineffectiveness of any of the brain regions responsible for language production or comprehension, including Wernicke’s area. Two of the many methods include a CAT scan and an MRI scan. A CAT scan (computerized axial tomography) is a non invasive medical test that allows physicians to diagnose a disease in the brain. A MRI (magnetic resonance imaging) scan is another type of non invasive medical test that allows physicians to view an image of the brain. Abnormalities in any area of the brain can easily be detected by either of these medical tests. An image of the brain is produced from these methods and physicians are able to view any tumors, cell death, lesions, or aphasias in the brain. If the abnormality is in any of the regions that are responsible for language, a language compromising and or vocalization disease is assumed and may be properly diagnosed.
In conclusion, there are many factors that contribute to the overall process of language comprehension. The complete processing of language requires many additional brain regions such as Broca’s area to properly produce and comprehend language. Neurologist Carl Wernicke demonstrated that Wernicke’s area is critical in understanding language that is spoken and written through his findings. This area of the brain, like any other, can be very sensitive to disease. Symptoms of aphasia should be taken seriously and proper medical methods should be