The life of an infant is certainly one to be
envied. They get food, they get unconditional
love, and of course they get a luxurious amount
of sleep. Now a new study from the University
of Arizona shows that these frequent naps are
more than just extra ZZZ's. They are actually
honing infants' basic abilities to learn about
the world around them.
University of Arizona psychologists Rebecca Gomez,
Richard Bootzin, and Lynn Nadel found that babies
who got a little daytime shut-eye were more likely
to exhibit an advanced level of learning, known
as abstraction. As they describe in the August
issue of Psychological Science, they played recordings
of "phrases" from an artificial language to forty-eight
15-month-old infants during a learning session.
For example, they repeatedly played phrases like
"pel wadim jic" until the babies became
familiar with them. These phrases contained three
units, with the first and last unit forming a
relationship. In this case, pel predicts jic.
Even though these are nonsensical sounds, Gomez
explains, the language shares some similarity
with structure found in English sentences, such
as the subject-verb agreement in "the companies
there are merging."
Before Gomez and colleagues tested the infants'
learning of this nonsensical language, some infants
took normally scheduled naps. Others were scheduled
at a time when they would not nap after learning.
When the infants returned to the lab, they again
heard the recordings-- along with novel phrases
in which the predictive relationship between the
first and last word was new. By carefully watching
the babies' gazes as they listened to both old
and novel phrases, Gomez was able to rate their
level of attention. Longer looking at a flashing
light (coinciding with the phrases) signaled attention,
which indicated the babies had learned a particular
phrase or relationship.
There were interesting differences between the
infants who had napped and those who had not.
The infants who did not sleep recognized the phrases
they had learned earlier, but the babies who had
slept in between generalized their knowledge of
the predictive relationships to new phrases. Gomez
interprets this as evidence that napping supports
abstract learning--that is, the ability to detect
a general pattern in new information.
This kind of abstract learning indicates a qualitative
change in memory, Gomez explains: "Such a change
plays an essential role in cognitive development
by sustaining sensitivity to previously encountered
information, while enabling learners to generalize
to novel cases."
