Brain Functions: The Language

Word naming and semantic categorizations respectively represent the ability to identify and name objects, and to understand and classify ideas.  These two functions are part of the group of language and communications skills.

The various language processes are undoubtedly among the most important and distinct human functions.  Just image what life would be like if you could not exchange verbal or written information with other human beings.  This rather catastrophic scenario would make you feel as though you had landed in the Stone Age.  In fact, many theoreticians suggest that the development of language skills sparked the explosive evolution of our distant ancestors.  These are the very skills that enabled them to rule over the animal kingdom.

Language is an extremely complex function.  A large part of your brain cerebral cortex, which is composed of several separate areas dedicated to accomplishing various tasks, is in fact dedicated to language.  Not only does your brain need to master several types of communication (written, spoken and body language) in terms of comprehension and production, it must also be able to integrate them in a coherent manner.

Language information processing is a lateralized function, which means that one side or hemisphere of your brain processes most of the information.  Approximately 95% of people use their left hemisphere to process language information.  The other 5%, mostly left-handed people, process language information using their right hemisphere.  Although the specific role of language areas is not yet perfectly understood, scientists have identified three large language areas in the brain.

One such area, known as Wernicke’s area, is chiefly responsible for your ability to understand the spoken words.  Wernicke’s area is located in the upper rear part of the temporal lobe, near the auditory cortex, which analyzes the sounds you hear, making it ideally located for decoding what others are telling you.  Although able to hear every sound clearly, patients who have sustained damage to their Wernicke’s area are unable to understand the meaning of what they are being told.

Language and speech are produced in regions of the brain located near areas that control mouth, face and hand movements.  One of these regions, Broca’s area, is located in the lower rear part of the frontal cortex.  It is named after the famous 19th century French neurologist, Paul Broca, who discovered the role of this part of the brain.  Lesions to Broca’s area result in the patient being unable to express himself in spoken or written language, even if he fully understands what he is being told.

Finally, our ability to understand the semantic relationships of a word, such as knowing that train is part of a class of objects called means of transportation, is governed by the lower part of the parietal lobe.  This part of the brain receives auditory, visual and tactile signals.  The neurons in this region are therefore ideally located for processing the phonetic and semantic aspects of language that allow us to identify and categorize objects.

What role does your other cerebral hemisphere play in language?  Your right hemisphere plays a pragmatic role; you use this brain area to understand the meanings, allusions, or various connotations of speech, such as verbal humor, the meaning of a metaphor or a question like “Do you have a light?”  Someone who has sustained an injury to his right hemisphere will take this question quite literally.  He will answer that he does not have a light even if he has a lighter in his pocket.  In addition, that person’s prosody will be affected, which means he will not be able to endow his speech with emotions.  In other words, this individual will always speak in a monotone, even if he is experiencing extreme grief or joy.