SAT Reading Practice Test 5

This passage is adapted from Joshua Foer, Moon walking with Einstein: The Art and Science of Remembering Everything. ©2011 by Joshua Foer.

In 2000, a neuroscientist at University College
London named Eleanor Maguire wanted to find out
what effect, if any, all that driving around the
labyrinthine streets of London might have on
5 cabbies’ brains. When she brought sixteen taxi
drivers into her lab and examined their brains in an
MRI scanner, she found one surprising and
important difference. The right posterior
hippocampus, a part of the brain known to be
10 involved in spatial navigation, was 7 percent larger
than normal in the cabbies—a small but very
significant difference. Maguire concluded that all of
that way-finding around London had physically
altered the gross structure of their brains. The more
15 years a cabbie had been on the road, the more
pronounced the effect.
The brain is a mutable organ, capable—within
limits—of reorganizing itself and readapting to new
kinds of sensory input, a phenomenon known as
20 neuroplasticity. It had long been thought that the
adult brain was incapable of spawning new
neurons—that while learning caused synapses to
rearrange themselves and new links between brain
cells to form, the brain’s basic anatomical structure
25 was more or less static. Maguire’s study suggested the
old inherited wisdom was simply not true.
After her groundbreaking study of London
cabbies, Maguire decided to turn her attention to
mental athletes. She teamed up with Elizabeth
30 Valentine and John Wilding, authors of the academic
monograph Superior Memory, to study ten
individuals who had finished near the top of the
World Memory Championship. They wanted to find
out if the memorizers’ brains were—like the London
35 cabbies’—structurally different from the rest of ours,
or if they were somehow just making better use of
memory abilities that we all possess.
The researchers put both the mental athletes and a
group of matched control subjects into MRI scanners
40 and asked them to memorize three-digit numbers,
black-and-white photographs of people’s faces, and
magnified images of snowflakes, while their brains
were being scanned. Maguire and her team thought it
was possible that they might discover anatomical
45 differences in the brains of the memory champs,
evidence that their brains had somehow reorganized
themselves in the process of doing all that intensive
remembering. But when the researchers reviewed the
imaging data, not a single significant structural
50 difference turned up. The brains of the mental
athletes appeared to be indistinguishable from those
of the control subjects. What’s more, on every single
test of general cognitive ability, the mental athletes’
scores came back well within the normal range. The
55 memory champs weren’t smarter, and they didn’t
have special brains.
But there was one telling difference between the
brains of the mental athletes and the control subjects:
When the researchers looked at which parts of the
60 brain were lighting up when the mental athletes were
memorizing, they found that they were activating
entirely different circuitry. According to the
functional MRIs [fMRIs], regions of the brain that
were less active in the control subjects seemed to be
65 working in overdrive for the mental athletes.
Surprisingly, when the mental athletes were
learning new information, they were engaging
several regions of the brain known to be involved in
two specific tasks: visual memory and spatial
70 navigation, including the same right posterior
hippocampal region that the London cabbies had
enlarged with all their daily way-finding. At first
glance, this wouldn’t seem to make any sense.
Why would mental athletes be conjuring images in
75 their mind’s eye when they were trying to learn
three-digit numbers? Why should they be navigating
like London cabbies when they’re supposed to be
remembering the shapes of snowflakes?
Maguire and her team asked the mental athletes
80 to describe exactly what was going through their
minds as they memorized. The mental athletes said
they were consciously converting the information
they were being asked to memorize into images, and
distributing those images along familiar spatial
85 journeys. They weren’t doing this automatically, or
because it was an inborn talent they’d nurtured since
childhood. Rather, the unexpected patterns of neural
activity that Maguire’s fMRIs turned up were the
result of training and practice.