London: A study on monkeys has suggested that some of the mental processing involved in reading evolved separately from the specialised language centres that are unique to human brains.
In the study, a group of baboons learned to discriminate real English words from non-words just by looking at them written down.
“It`s not that baboons can read,” New Scientist quoted Michael Platt of Duke University in Durham, North Carolina, one of the researchers involved in the study, as saying.
Jonathan Grainger and colleagues of the University of Aix-Marseille, France, trained six captive Guinea baboons (Papio papio) to look at letters on computer screens.
Sometimes the baboons were shown a real, four-letter English word, but on other trials they were shown a four-letter non-word. They had to press one of two buttons, depending on whether a word or non-word was shown, and were rewarded with food if they got it right.
After a month and a half, the baboons had learned dozens of words: one could reliably identify 308.
One surprising achievement is that after they had been practising for some time, they became much better at identifying real words that they had never seen before.
This indicates that they had learned the rules that determine which letter orderings form real words, and could apply these rules to distinguish them from unlikely letter orderings.
The findings suggest that the brain mechanisms human children use when they first learn to recognise written words are evolutionarily ancient, and were co-opted when written language came along, around 6000 years ago.
Tecumseh Fitch at the University of Vienna in Austria said the ability to construct rules that help us categorise similar objects into groups may be widespread in the animal kingdom, although the animals would not have evolved it to deal with words.
“I wouldn``t be surprised if pigeons could do this,” he stated.
Reading is a recent cultural innovation, said Fitch, meaning there has not been enough time for humans to evolve specialised brain circuitry for this skill.
So it makes sense that reading relies on visual abilities that came about a long time before written language, for a different purpose.