How the Brain Processes Language

A little taste of psycholinguistics.

When you want to say a word, your brain needs to choose the word from your lexicon, figure out which sounds are in the word, and communicate to your articulators how to say the word. Then, you finally say the word aloud. All of that happens in a matter of milliseconds.

When you hear a word, your brain needs to hear the sounds, connect them for meaning, and then connect them to a word that shares that meaning in your lexicon. Again, all of that happens in a matter of milliseconds.

Considering that we subconsciously perform these processes thousands of times a day, it’s a marvel how the brain processes language for us

So what exactly is going on in our brains when we language?

My professor used to say that you can’t turn a corner of the brain without finding a region that is used for language in some way. In other words, language uses almost every part of the brain in one way or another. But there are a few parts of the brain that exclusively deal with language. Today, we’re studying the two biggest of these regions: Broca’s area and Wernicke’s area. We’re discussing what each of these regions does and what happens if there’s damage to one of these areas (e.g. in the case of a stroke or an accident).

Broca’s Area

Broca’s area is named after the French neuroscientist who discovered it, Paul Broca. In 1861, Broca worked at a hospital and a patient was transferred to his ward. This patient was nearly dead. Broca got to him shortly before he died and realized something odd. The man could speak. But he only spoke a single word. That word was “tan.” The word itself wasn’t curious. What was curious was how brain trauma caused a man to not be able to produce any other word other than “tan”. After he died, Broca examined the patient’s brain and realized that his brain trauma was localized in a single area.

In subsequent years, Broca received similar postmortem brains from people who could only say a few words after suffering from brain trauma, and who had the same area of the brain damaged. Broca figured that this part of the brain must be key to language, specifically to the production aspect of language.

And he was right. The part of the brain we now call Broca’s area is key for how we produce language. It’s the part of our brain that tells our articulators how to move. For spoken languages, that means it’s telling our face, jaw, and tongue how to position themselves for the desired sounds. For signed languages, that means it’s telling our hands and body how to move for the desired signs.

It also coordinates some of the syntax: tells us how to put words in the past tense, when to use determiners, prepositions, etc.

Since this area is key for producing language, when the Broca’s area is damaged due to a stroke or trauma, people find it hard to speak. They may stutter a lot before finally getting a word out. They also might find it really hard to use grammar terms, like determiners or prepositions. It can be incredibly frustrating because their intellect is in tact. They know what they want to say, but have trouble actually saying it. Here’s a video of what they may sound like:

He can understand the questions, but has a little trouble finding the right words to express his thoughts.

More or less where they’re located in the left hemisphere of the brain.

Wernicke’s Area

Now for the second part of the brain that deals exclusively with language: Wernicke’s area. But first, the backstory:

Carl Wernicke was a neurologist. And he noticed that he had patients who would come in and speak to him fluently. The strange part was that what they were saying was rather nonsensical. He gathered those patients and studied their brains. They all had damage done to a similar part of their brains. And it wasn’t Broca’s area, which was discovered a decade before. It was what we now call Wernicke’s area.

Wernicke’s area is key for understanding language. It’s the part of the brain where words are retrieved from the lexicon. And it’s the reason why words and sentences make sense to us.

Since this part of the brain mainly deals with language perception, if someone suffers a stroke or trauma in this part of the brain, they find it really hard to understand speech. Not only that, but when they go to say something, their speech may be really confusing to the listener. Unfortunately, they often don’t know that their speech is confusing, which might lead to frustrations. Here’s a video of what they may sound like:

Unlike the last video, he is completely fluent. But since Wernicke’s aphasia deals with comprehension, his speech is filled with phrases that don’t make too much sense.

Conclusion

I started this newsletter talking about how amazing it is how quickly the brain works in order to produce and perceive language. And those processes sounded amazing with the vague descriptions I used. But now that we’ve learned more about the brain, we can add some more details. Here’s all that happens in your brain when you produce a single word:

First, you find the word in your lexicon, which is in your Wernicke’s region. Then, the nerve fibers that connect your Wernicke’s and Broca’s areas transmit only the phonetic information of the word from your Wernicke’s area to your Broca’s area. Once it’s in your Broca’s area, your Broca’s area interprets the sounds and sends the information needed for the articulators to the motor cortex, which then makes the movements for the sounds. And finally you produce the word.

All of that happens almost instantaneously. Wow, right?

Discussion

I hope you enjoyed this little introduction into psycholinguistics!

To me, learning about how the brain processes language makes me amazed and grateful. First, it reminds me how miraculous it is that our brains can do this and that we can use language (after all, we’re the only species that can). Second, it reminds me how quickly this ability can be altered through brain trauma.

I’d love to know your thoughts below!

Works Cited

Bergmann, A., Hall, K. C., & Ross, S. M. (2007). Language files. Materials for an.