Brain has its own predictive text function

It could explain why we can sometimes finish the sentences of others - scientists have found the brain has a built in predictive text function like those on a mobile telephone.

By Richard Alleyne, Science Correspondent
Published: 7:30AM BST 15 Oct 2009
Researchers believe the reason that dyslexics struggle to read at speed is that they are missing the ability, and hope their discovery could lead to new treatments for the condition.
The British neuroscientists found that the reason most people can predict words and sentences as they are being scanned by the eye.

Rather than read every word and sentence to the end before coming up with its meaning, the brain makes an educated guess and then moves on.
As we become more literate, the brain becomes ever more adept at predicting sentences and therefore quicker at reading.
Traditionally it was thought that a part of the brain known as the angular gyrus acted like a "dictionary" that translates letters and words into meaning, said Professor Cathy Price, a cognitive neuroscientist at University College London.
"In fact, we have shown that its role is more in anticipating what our eye will see – more akin to the predictive texting function on a mobile phone," she said.
"We think this brings us a step closer to our understanding of dyslexia. It has changed my knowledge of how reading occurs."
The discovery, published in the journal Nature, came after a unique study into former guerrilla fighters in Colombia.
The team scanned the brains of illiterate adult rebels, who had had no education, before and after they had undertaken a five year reading and writing course.
They found that for those participants who had learnt to read, the density of grey matter - where the 'processing' is done - was higher in several areas of the left hemisphere of the brain.
These were the areas that are responsible for recognising letter shapes and translating the letters into speech sounds and their meanings.
Reading also increased the strength of the "white matter" connections between the different processing regions.
Particularly important were the connections to and from the angular gyrus, which is at top left of the brain, it was found.
Scientists have known for over 150 years that this brain region is important for reading, but the new research has shown that its role had been misunderstood.
Previously, it was thought that the angular gyrus recognised the shapes of words prior to finding their sounds and meanings. In fact, the researchers showed that the angular gyrus is not directly involved in translating visual words into their sounds and meanings.
Instead, it supports this process by providing predictions of what the brain is expecting to see.