The young brain is a sponge for knowledge, primed to soak up skills and information with an ease that it will never match again. And those skills may last a lifetime: A Report  in tomorrow's issue of Science shows that, at least in owls, early life experiences leave a memory trace on the brain that can lie dormant until adulthood and then be reactivated. The result suggests that exposing children to more experiences at a young age might make them smarter adults. To try to find out why the young brain is so receptive to learning, Stanford University neuroscientist Erik Knudsen has been studying the ability of owls to locate sounds in space. The owl coordinates what it sees and hears in a part of its brain called the optic tectum, where it merges auditory and visual maps of space. Knudsen and his colleagues disrupted this mapping system by placing prisms over the birds' eyes that shift what they see to one side. This creates a problem for the owls, Knudsen says, because "if you optically displace the visual map, you have to adjust the auditory map physiologically to bring the two maps back into alignment."
In the new experiments, Knudsen tested whether the previously trained birds can readjust their auditory maps to the prisms many months later, when they are well into adulthood. They could. "I put these prisms on birds that had been without them for half a year, which is a long time in bird life, and--Voilà!--3 weeks later, I saw this neural learning appear," says Knudsen. The trick only worked with owls that had worn the same special glasses when they were young.
The findings are "very important," says neurobiologist Carla Shatz of the University of California, Berkeley, "because it says that there is a possibility of reactivating connections that were established [earlier]. Even if the skills haven't been used for a long time, the learning is still there."