Sleep & Memory

Ian Goddard igoddard at
Sat Apr 6 00:20:00 EST 2002

Babies learn in their sleep

19:00 06 February 02
Alison Motluk

Students should be jealous - not only do babies get to doze their days
away, but they have also mastered the art of learning in their sleep.

By the time babies are a year old they can recognise a lot of sounds
and even simple words. Marie Cheour at the University of Turku in
Finland suspected they might progress this fast because they learn
language while they sleep as well as when they are awake.

To test the theory, Cheour and her colleagues studied 45 newborn
babies in the first few days of their lives. They exposed all the
infants to an hour of Finnish vowel sounds - one that sounds like
"oo", another like "ee", and a third boundary vowel peculiar to
Finnish and similar languages that sounds like something in between.
EEG recordings of the infants brains before and after the session
showed that the newborns could not distinguish between the sounds.

Fifteen of the babies then went back with their mothers, while the
rest were split into two sleep-study groups. One group was exposed
throughout their night-time sleeping hours to the same three vowels,
while the others listened to other, easier-to-distinguish vowel


When tested in the morning, and again in the evening, the babies who
had heard the tricky boundary vowel all night showed brainwave
activity indicating that they could now recognise this new sound. They
could identify the sound even when its pitch was changed, while none
of the other babies could pick out the boundary vowel at all.

Cheour doesn't know how babies accomplish this night-time learning,
but she suspects that the special ability might indicate that unlike
adults, babies don't "turn off" their cerebral cortex while they
sleep. The skill probably fades in the course of the first year of
life, she adds - so forget the idea that you can pick up tricky French
vowels as an adult just by slipping a language tape under your pillow.

But while it may not help grown-ups, Cheour is hoping to use the
sleeping hours to give remedial help to babies who are genetically at
risk of language disorders.

Journal reference: Nature (vol 415, p 599)

19:00 06 February 02



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