Which is easier to remember: 4432879960 or
443-287-9960? The latter, of course. Adults
seem to know automatically, in fact, that long strings of
numbers are more easily recalled when divided
into smaller "bite-sized chunks," which is why we break up
our telephone and Social Security numbers
in this way.
Now researchers at Johns Hopkins have discovered that
children as young as 14 months old can — and do
— use the same technique to increase their working
memories, indicating that "chunking"
information in this way is not a learned strategy but is,
instead, a fundamental aspect of the human
"Our work offers evidence of memory expansion based on
conceptual knowledge in untrained,
pre-verbal subjects," said Lisa Feigenson, assistant
psychological and brain sciences in
the Krieger School of Arts and Sciences, who worked on the
study with colleague Justin Halberda.
"What we have basically done is show that very young
children, who can usually only keep track of
about three objects at once, can keep track of more if they
use the kind of conceptual, linguistic,
perceptual and spatial cues adults also use."
An article on this research appears in the July 14
issue of the Proceedings of the National
Academy of Sciences.
In the team's experiment, 14-month-olds were shown
four toys, which were then hidden in a
box. The children then were allowed to search for the
missing toys. Sometimes, two of the four toys
were secretly withheld in another place. The researchers
observed how long the youngsters continued
to search the box, the idea being that they would search
longer if they remembered there were more
toys yet to be found.
The researchers found the children would search longer
when the four toys consisted of two
groups of two familiar objects, cats and cars, and one of
each type had been withheld. That indicated
that the youngsters were using mental chunking as a way to
recall more items at a time.
The team also found that 14-month-olds can use spatial
grouping cues (the researchers grouped
six identical orange balls in three groups of two before
hiding them) to expand memory, in the same
way that adults group digits when remembering phone
numbers. When provided with such cues, the
little ones could remember up to six objects.
These results suggest that memory is not merely a
passive storage system that makes a "carbon
copy" of our experiences. Instead, Feigenson says, the
results show that from at least early
toddlerhood onward, memory is constantly being restructured
and reorganized to maximize its
efficiency. The researchers' results may have implications
for educational strategies or for helping
those who suffer short-term memory problems. But more
directly, they show that the memory
systems of young infants are surprisingly similar to those
This research was supported by the National Institute
of Child Health and Human Development
and a James S. McDonnell Foundation Scholar Award.