The characters in Eon are able to learn foreign languages in a matter
of hours, including modern colloquialisms, by visiting the Thistledown
library. The information is input into their mind directly, bypassing
any conscious activity. This would probably be done by producing
bursts of light and sound that would stimulate different parts of the brain.
Similar technology is explored in Neil Stevenson's Snow Crash, where
binary viruses can enter the mind directly through the eyes.
Many people believe that they can input information directly into their
mind. Information tapes to be played during sleep have been hugely
successful worldwide, as have special learning programs such as Kevin Trudeau's
Mega Memory.