The Complexity of Language
Language is a cognitive skill that binds people together. Language allows people to communicate complex thoughts and emotions with one another. While we often think of language as the words that come out of our mouths or the sentences we write on paper, language is a very complex skill that involves different regions of our brain. When someone has a stroke, people may lose the ability to understand and produce language, a condition known as aphasia. In this article, we break down the components of language and elaborate on the two types of aphasia someone can develop as a result of a stroke.
Where do we produce and process language?
Language is developed and stored in the brain. Language is the result of auditory and visual inputs from the environment causing thought processes that lead to verbal outputs such as speech and writing. Research has found that are two major pathways have been identified: the audio ventral stream and audio dorsal stream.
The Broca’s area, or the part of the brain responsible for producing speech, is found in the left frontal lobe. Broca’s area has connections to the media temporal gyrus to the temporal pole and inferior frontal gyrus. These connections are part of the audio-ventral stream. This stream informs people of “what” is being communicated. It processes sound, distinguishes background noise from meaningful sounds, and is needed to comprehend sentences. Connected to Broca’s area is Wernicke’s area.
The Wernicke’s area, located within the posterior superior temporal gyrus, links language comprehension for both written and spoken word. Wernicke’s area is part of the audio-dorsal stream. The audio-dorsal stream is formed of connections from the auditory network, parietal lobe, and inferior frontal gyrus. The audio-dorsal stream helps the brain understand “where” sound is coming from and is essential for speech production, repetition, and verbal memory.
Is the left hemisphere the only hemisphere involved in language?
Nope. Research has also found the involvement of the right hemisphere in language. Originally thought to be only controlled by the left hemisphere, the right hemisphere is active in comprehending emotion and attitudes conveyed within language. Right hemisphere damage can cause someone not to understand when someone tells a joke, or if someone non-verbally communicates amusement of something said. In this sense, the right hemisphere is responsible for comprehension of idiomatic/non-literal spoken and written language.
Language is a complex brain function that many people take for granted. Numerous different parts of the brain are required to communicate. While language comprehension is different from language communication, damage to one area of the brain may impact the interplay of comprehension and communication. Without this advanced cognitive skill, we would not have the ability to explain and express complex ideas and information. Language is a skill that we often take for granted. Thankfully there are 3 different type of therapists who work with people who have suffered language loss.