What does it mean to know a word?

You may think it is to know what it sounds like, its meaning, and what it looks like in print. But knowing a word is more than this. 

It is knowing multiple meanings for a word, and knowing the other words that sound similar, meaning similar things, that look similar.

Learning new words

So when we teach a word, the learning process needs to be about explicitly learning the attributes of a word, but also about connecting that word to other words that we already know, or integrating each word into our mental lexicon (the memory store that we have of words).

How do we get something into our mental lexicon?

The complementary learning systems account was first put forward by McClelland, McNaughton and O’Reilly in the mid-1990s. This proposes that one part of the brain, the hippocampus, is responsible for the fast learning of words and their attributes. 

With consolidation into memory, the neocortex gets involved and supports the integration of words into the mental lexicon. 

And this process of consolidation appears to rely on sleep. 

Sleep and memory

But could sleep really be a key factor in the learning of new words?

Lisa Henderson and Emma James, from the University of York, set out to explore word learning in a group of children aged 10 or 11. They were interested in how children learn new words from stories, since listening to and reading stories provides important opportunities for learning new words. 

In the study, children could listen to and read the stories, which contained 16 new (made-up) words like “crocodol” and “fountel” that sounded like known words (crocodile, fountain).

The researchers looked at how well children remembered what the words sounded like and what they meant immediately after reading the stories, and 24 hours later. Importantly, this allowed them to look at memory before and after sleep. 

Children were more able to remember words after sleep and children who knew more about words to start with learned the words better. However, both of these findings were more robust for remembering the sound of a word than remembering its meaning.

What does this mean? 

Lessons for teens

Well, this study builds on a large body of research that shows that sleep is important for word learning in adults and children. At Royal Holloway, we are taking this further by investigating whether this is the case for adolescence. 

Adolescence is a really interesting time to study as there are key biological changes that affect the way that adolescents sleep, with their natural body clock becoming more like a “night owl” (wanting to go to bed later and get up later) than a “morning lark” (going to bed and getting up earlier). 

In addition, during adolescence a number of factors start influencing the amount that young people sleep, and consistency around sleep. 

For example, adolescents start having more autonomy about what they do in the evening and what time they go to bed. Jess Dyson, who is leading this work, is a PhD student in the lab, co-supervised by Dr Jakke Tamminen and funded by the Waterloo Foundation. More findings soon!

Dr Jessie Ricketts is director of the Language and Reading Acquisition (LARA) Lab at Royal Holloway University 

To find out more about Jess Dyson’s research, visit the LARA website or the Sleep, memory and Learning Lab.