Language and the Brain

Language and the Brain in Psycholinguistics

Who studies the phenomena of language learning and the brain? Psycholinguistics is the study that aims to describe the psychological processes and connections that allow humans to use language. Psycholinguistic research relies on linguistics. Linguistics is the study of the structure of language -- all language.

Psycholinguistics' foundational studies involve several aspects of language such as acquisition, comprehension, and production. But psycholinguists study more about language and the brain than just these studies. For example, some of the top research and experiment portions of this field focus on the neurology of language functioning. This is mainly for researchers who are focused on aphasia, sex differences, and language after injury or congenital injury in the immature brain, as well as developmental disorders of language (referred to as dysphasia).

Language and the Brain: Development

As we age in our early childhood, there are critical periods of brain development. These critical periods allow for the proper development of many skills including language. There are specific periods in childhood where the brain is more active in forming new connections for specific abilities.

You can think of these critical periods as doors opening and closing. One of the first doors to open for language development occurs early in life. Infants are able to spot the differences between the sounds of all languages but by six months of age, they recognize fewer differences in sounds that are not relevant to their native language.

During our preschool years, there is an open door for syntax and grammar to be more easily recognized. The door for new grammar and syntax recognition closes around the age of five or six years although a new door opens for adding new words and vocabulary which never closes.

Fig. 1 - Critical periods in our language development

There are critical periods when language is procured during brain development, but where does this occur in our brains?

Relationship Between Language and the Brain

It is from our brain that language, and therefore speech, originates. There are certain areas of the brain that are responsible for these functions such as understanding words and sentences. There are two regions in the brain where these language functions reside -- on the left side of the brain and where there are nerve connections. The network of nerves is important as it allows for the exchanging of information.

While these processes can support each other they can also compete with one another. This network showcases the competition between the processes of social cognition and the processes of memory. It also offers a natural explanation for the effects that frequency of usage can have on development.

Language Processing in the Brain

There are two particular areas that prove to be most important to language processing within the brain -- Wernicke's area and Broca's area.

Broca's Area

It was in 1865 when French physician, Paul Broca, had an interesting experience with someone who recently suffered damage to their left frontal lobe. What was so interesting? The individual who had damage to their left frontal lobe would have a difficult time speaking but could sing familiar songs and understand speech. How is this possible?

This phenomenon would later be referred to as aphasia meaning that there was damage to a specific area of the brain. Aphasia is the impairment of language due to damage in either Broca's area or Wernicke's area of the brain to be more specific.

There is more to the puzzle when it comes to brain functions and language.

Wernicke's Area

About a decade later, a German investigator, Carl Wernicke developed his own studies of the brain and happened upon another phenomenon related to aphasia. When there is damage to the left temporal lobe (which will later be called Wernicke's area) the ability to understand other's sentences or to speak something other than meaningless sentences occur.

Sign language and the Brain

What about communication that doesn't require sounds? Is it possible to learn a language without the ability to speak? Simply put, the answer is yes and a solid example of this is learning sign language. Where does this process of learning sign language happen within our brains? Are the locations of language processing in the brain the same for sign language as it is for spoken language?

Firstly, sign language is referred to as visuospatial language.

Further research has revealed that those who are deaf and using sign language have more activity in the left hemisphere of their brain as well as the right hemisphere. Brain scans showed that those with damage to the left hemisphere could still process nonlanguage visuospatial relations. This was further proof that language functions are focused in the left hemisphere of the brain. Those who had damage to the right hemisphere showed opposite deficits. Meaning that there was proof that visuospatial skills pertained to the right hemisphere of the brain.

Fig. 2 - Is sign language a different process in our brains?

Those who rely on sign language for communication, therefore, are using both the left and right hemispheres of their brain. Researchers concluded that language is modular (meaning that each part of the brain performs a certain function) (Bellugi, Kilma, & Poizner, N.A.).

Is learning sign language beneficial to brain functioning? Science has shown that learning sign language is the same as learning a foreign language and requires the same amount of effort as any other spoken language. Learning sign language has been proven to strengthen reasoning and cognitive processes as well as increase our memory, creativity, communication skills, and attention.