Saturday, August 01, 1998
This bespectacled little owl was part of a study about the effects of early learning on the brain. For example, a child who learns a language while very young and then stops speaking the language will find it far easier to relearn years later than will an adult attempting to master it for the first time. A Stanford neuroscientist may have found why this is so. Early learning, says Eric Knudsen, generates the formation of neural connections that can be reactivated in adulthood. Knudsen put spectacles on three ten-day-old barn owls that shifted their vision 23 degrees to the right. The young owls swiftly learned to compensate for the distortion. After 220 days, Knudsen took off the birds' glasses. In six months their vision and responses returned to normal. Knudsen then put the goggles back on. Several weeks later the owls had once again adapted, but two owls that had received no infant training could not adaptotheir distorted vision confused them when they hunted. Electrodes inserted into the trained birds' brains showed that signals from visual and auditory neurons had integrated to respond to the distortion. (Barn owls rely on vision and hearing to hunt.) "Our hypothesis is that early learning has changed the anatomy of the neural connections," says Knudsen. "Early experience can have a persistent effect on the way the brain is wired."