The study was published in Nature.
Each of the monkeys performed significantly better than 50 percent, which they would have scored by randomly guessing which letters formed words or non-words. They averaged almost 75 percent right, with some scoring 90.
The study is "extraordinarily exciting," said cognitive psychologist Stanislas Dehaene of the College de France in Paris, an expert on the neural basis of reading who was not involved in the research, and author of, Reading in the Brain: The New Science of How We Read. "For the first time, we have an animal model of a key component of literacy, the recognition of the visual word form."
The study was intended less to probe animal intelligence than to explore how a brain might learn to read. It suggests that, contrary to prevailing theory, a brain can take the first steps toward reading without having language, since baboons don't. A similar hypothesis has been put forward by Dr. Robert Titzer, developer of the Your Baby Can Read: Early Language Development System system, that uses the pattern recognition ability of infants and toddlers as a base to learn word recognition, and accelerate reading in children.
"Their results suggest that the basic biological mechanisms required for reading have deeper evolutionary roots than anyone thought," said neuroscientist Michael Platt of Duke University, who co-authored an analysis of the study. "That suggests that reading draws on much older neurological mechanisms" and that apes or monkeys are the place to look for them.
Reading has long puzzled neuroscientists. Once some humans started doing it (about 5,000 years ago in the Middle East), reading spread across the ancient world so quickly that it cannot have required genetic changes and entirely new brain circuitry. Those don't evolve quickly enough. Instead, its rapid spread suggests that reading co-opted existing neural structures.
To be sure, other animals have learned to recognize letters. In a 1982 experiment, for instance, pigeons were able to identify all 26 letters of the English alphabet.
But the baboons were not simply memorizing which strings of letters were words, said Grainger. When shown a word for the first time, they identified it correctly about 70 percent of the time, suggesting the animals were applying the statistical rules they had inferred.
The word-savvy baboons may be drawing on "more generalized learning mechanisms and visual processing abilities rather than specialized mechanisms unique to humans," said Diana Reiss of Hunter College in New York, who has done pioneering work in animal intelligence.
A prime candidate for those processing abilities lies in a region of the brain that becomes active when people read. Discovered by Dehaene, it is called the "visual word form area" and is located behind the left ear. It recognizes strings of letters, and the more active it is in 7- to-18-year-olds, studies show, the better readers they tend to be.
"Neuroimaging shows that this region is specific for words and not meaningless strings of letters," said Duke's Platt.
Since reading arrived on the scene a mere blink of the eye ago, evolutionarily speaking, the visual word form area cannot have developed in order to support reading. If baboons or human ancestors also had this structure, the question becomes what they used it for. Best guess: recognizing objects by visually assembling their parts, such as tall cylinder + bushy top = tree.
Among the many surprises in the study is that it involved baboons rather than a primate known for braininess.
"Guinea baboons have a lot of social savvy, since they have to learn about complex male-male and male-female interactions in their troop," said primate curator Craig Demitros of the Brookfield Zoo outside Chicago. "They're smart, but not at the level of chimps."
Apart from the glimpses it provides into the evolution of the brain's ability to read, the study has implications for education. "You might conclude that phonics doesn't work" as well as teaching children to read by recognizing the entire word, said Platt. "This study suggests that reading is all about pattern recognition and not working out phonemes."
The team next plans to try to teach the baboons an artificial alphabet. This would give greater control over the visual information that defines individual letters, Grainger explains, and would provide a more precise idea of how baboons master word recognition.
33rd Square
