Test helps decode how the brain reads words

Understanding how the human brain decodes letters to read words is a step closer thanks to an improved psychological test, say University of London researchers.

The test could help experts understand how the brain makes sense of some jumbled letters - but not others.

The findings could help people to overcome reading difficulties and dyslexia, the researchers said.

It may also explain the differences in people's reading abilities.

In order to read successfully, readers have to identify the letters in words and also accurately code the positions of those letters so that they can distinguish between words like CAT and ACT.

Yet, at the same time, for example, it's possible for readers to "dael wtih wodrs in wihch not all teh leettrs aer in thier corerct psotiions".

This research, led by Prof Colin Davis at Royal Holloway, University of London, and funded by the Economic and Social Research Council, could help psychologists unravel the subtle thinking mechanisms involved in reading.

Prof Davis said: "How the brain can make sense of some jumbled sequences of letters. but not others is a key question that psychologists need to answer to understand the code that the brain uses when reading."

For many years researchers have used a standard psychological test to try to work out which sequences of letters in a word are important cues for the brain.

But this technique had limitations that made it impossible to probe more extreme rearrangements of sequences of letters.

Crack the code

Prof Davis's team used computer simulations to work out that a simple modification to the test would allow it to question these more complex changes to words.

This made the test more valuable for comparing different coding theories, they said.

"For example, if we take the word VACATION and change it to AVACITNO, previously the test would not tell us if the brain recognises it as VACATION because other words such as AVOCADO or AVIATION might start popping into the person's head.

"With our modification we can show that indeed the brain does relate AVACITNO to VACATION, and this starts to give us much more of an insight into the nature of the code that the brain is using - something that was not possible with the existing test."

The modified test could allow researchers not only to crack the code that the brain uses to make sense of strings of letters, but also to examine differences between individuals - how a 'good' reader decodes letter sequences compared with someone who finds reading difficult.

Prof Davis added: "These kinds of methods can be very sensitive to individual differences in reading ability and we are starting to get a better idea of some of the issues that underpin people's difficulty in reading."

Dr John Rack, head of research development and policy at Dyslexia Action, said the research was "interesting" and contributed to a wider understanding of reading processes.

But he was unsure what implications it might have for teaching children to read.

"It should be stressed that it is one thing to understand how a developed system works and quite another to understand how that system takes shape through teaching and learning.

Dr Rack added: "We would be particularly interested to hear about new research focusing particularly on development and teaching."