I often take the ability to learn a new word for granted. Today I was reading a book and came across the word caul (kôl). Having never encountered this word before, I looked up its definition to discover that it’s a part of the amniotic membrane enclosing a fetus, and that is it often found stuck to the child’s head after birth. Oddly enough, a few hours after reading this particular passage, I found myself unable to recall the word, despite being able to vividly recall its definition. As I both enjoy using obnoxious words, and disgusting people in the name of science, I wanted to learn more about how we learn words, and thankfully for me I didn’t have to look very far.
Researchers at the King’s College London Institute of Psychiatry have mapped the neural pathway involved in learning words and have made some amazing findings. Using function magnetic resonance imaging (fMRI), a fancy technique that allows researchers to look at areas of blood flow in the brain to detect areas of activity, researchers mapped the neural pathway required for learning new words. They found that this pathway is only found in humans, despite the fact that it has been well documented that chimps can learn words. This pathway likely explains why it is that while the average adult’s vocabulary consists of around 30,000 words, chimps struggle to learn as few as 100.
The process of learning a word is a choreographed event. The auditory region of the brain hears a word, and makes a connection to the motor regions of the brain through a specific bundle of nerve axons referred to as the arcuate fasciculus. In this way, hearing a word translates to the physicality of saying a word; the movement of your lips and tongue involved in saying the word. The researchers even found a link between the physical structure of the arcuate fasciculus, how quickly it was able to conduct and propel the electrical synapse, and a patient’s ability to recall words.
This research highlights the importance of both hearing and speaking when learning anything from the word caul (it’s very likely that because I only read the word it simply didn’t stick,) to an entirely new language. This research demonstrates the importance of speaking, articulating, and interaction in the acquisition of vocabulary. So tonight, go ahead and read this article aloud to your spouse. I guarantee you’ll learn a new word or two.
To read the full press release, and to find a link to the PNAS paper, use this link.
Image CC Flickr user JD Hancock