If human memory were truly digital, it
would have just received an upgrade from something like the
capacity of a floppy disk to that of a flash drive. A new
study found the brain can remember a lot more than previously
believed.
In a recent experiment, people who viewed
pictures
of thousands of objects over five hours were able to remember
astonishing details afterward about most of the objects.
Though previous studies have never measured
such astounding feats of memory, it may be simply because
no one really tried.
"People had never tested whether
people could remember this much detail about this many objects,"
said researcher Timothy Brady, a cognitive neuroscientist
at MIT. "Nobody actually pushed it this far."
When they did push the human brain to
its limits, the scientists found that under the right circumstances,
it can store minute visual details far beyond what had been
imagined.
Those circumstances include looking at
images of objects that are familiar, such as remote controls,
dollar bills and loaves of bread, as opposed to abstract artworks.
Another factor that seemed to help was
motivation to do well: The participant who scored highest
won a small prize of money (the researchers refused to say
exactly how much).
"You have to try," said MIT
co-author Talia Konkle. "You have to want to do it."
The study, funded by the National Science
Foundation, National Institutes of Health, a National Defense
Science and Engineering Graduate Fellowship, and a National
Research Service Award, was detailed in the Sept. 8 issue
of the journal Proceedings of the National Academy of
Sciences.
In the experiment, 14 people ranging
from age 18 to 40 viewed nearly 3,000 images, one at a time,
for three seconds each. Afterwards, they were shown pairs
of images and asked to select the exact image they had seen
earlier.
The test pairs fell into three categories:
two completely different objects, an object and a different
example of the same type of object (such as two different
remote controls), and an object along with a slightly altered
version of the same object (such as a cup full and another
cup half-full).
Stunningly, participants on average chose the correct image
92 percent, 88 percent and 87 percent of the time, in each
of the three pairing categories respectively. Though 14 subjects
may not sound like a huge sample, the fact that they each
recalled the objects with very similar rates of success suggests
the results are not a fluke.
"To give just one example, this means
that after having seen thousands of objects, subjects didn’t
just remember which cabinet they had seen, but also that the
cabinet door was slightly open," Brady said.
Even the researchers didn't expect
quite such high recall rates.
"We had the intuition that it might
be possible, but we were surprised by the magnitude of the
effect," said study leader Aude Oliva, also of MIT. "These
numbers, higher than 85 and 90 percent, impressed us and also
impressed a lot of people who heard about the work."
So now that we know the brain's memory
is so fantastic, are we all out of excuses for forgetting
friends' birthdays?
Luckily not, Brady said.
"To some extent it's about attention,
actively encoding specific details into memory," he told
LiveScience. "If we tried really hard we actually
could remember when someone's birthday was: if you say
to yourself, 'The birthday is on this day and that relates
to these other things that I remember.'"
Basically, he said, we can remember most
things we put our minds to, if we invest enough attention
and effort into trying to store them in the first place.