Pablo Gomez (associate professor, Psychology) studies word recognition, specifically the way readers retrieve lexical items from an internal representation of words. His work could benefit adults and children with dyslexia. Here's how.
Q: What’s the big picture of your work?
When you see a written word, there’s a process for recognizing it, and that recognition is a building block for comprehension. For example, if you read B-A-N-K, your brain extracts graphic features, letter features, word-level features — but you still don’t know if the word refers to the side or a river or a financial institution. My work ends at the moment of recognition. Beyond recognition — putting together meaning — I don’t study that.
In my field, a big question of the past 10 years has been “How do we extract the position of the letters when we see a word?” If I show you the letters J-U-G-D-E, you won’t notice the mistake and will read J-U-D-G-E, especially if the surrounding words are “lawyer” or “courtroom.” Older models of word recognition assume that we perfectly encode letter positioning which is clearly not true.
Q: Which brings us to your research.
For the past several years — working with Manuel Perea, a senior lecturer of cognitive psychology at the Universitat de València — I have hypothesized that when we transpose letters while reading, it’s because our perception systems are not perfect when we initially encode letter location. In simpler language, the closer the letters are, the greater the likelihood of transposing. This premise has a lot of implications for “problem” readers.
For example, our research suggests a simple font change could help dyslexic children read better, while at the same time boosting reading speed and comprehension among normal children without this disability. All it takes is a moderate — practically unnoticeable — increase in the amount of space between letters on a page. While the results of our research are still in their early days, they are significant.
Q: How did you test your hypothesis?
We wanted to find out whether children — dyslexic and normal — could read better when we reduced the “crowding” effect: when letters are too close, they blur together a bit, thereby increasing perceptual uncertainty. Of course, too much spacing and the eye won't recognize the stretched-out word. It's a rather intuitive idea, but one that hadn't been thoroughly tested.
We performed four experiments using a well-tested lexical decision task to determine the impact of a modest increase of inter-letter spacing. The participants — adults, young readers, and young readers with dyslexia — would see a series of letters appear on a computer screen. They were instructed to press a button only if the letters formed a word they recognized and to respond as rapidly as possible without making too many mistakes. When we increased inter-letter spacing, all the participants were able to read and recognize words more quickly. In fact, we found a substantial reading benefit from a very small increase in inter-letter spacing.
To test whether this benefit applied beyond the laboratory, we also presented the children with two short stories and a reading comprehension test. While the overall performance of normal children did not increase significantly when inter-letter spacing was increased (just two words per minute faster), the dyslexic children showed a substantial improvement in reading times (a boost of eight words per minute) and also in comprehension (average score of 56.3 percent versus 46.3 percent).
Q: What are some possible implications of your data?
Publishers of children's books already follow guidelines to choose more readable fonts, but those guidelines are based more on aesthetics and industry standards than on research. If children's books publishers modestly increased their default inter-letter spacing, that could improve reading comprehension among children of all skill levels. But more research is needed to determine optimal spacing, font, and size for general reading comprehension.
Most word processing programs already allow users to increase inter-letter spacing. We hope that electronic readers, such as Kindle or iPad, will soon give readers the same option. I don’t want to oversell our findings, but at the very least children and adults who struggle to read would benefit if they could control letter spacing.