NOTEBOOKand printed words, which are normally
processed by regions within these parts of
the brain.
This uncertainty stemmed from neuro-
scientists not having a clear understanding
of how the brain’s visual system reorganizes
itself after trauma caused by disease,
injury, or surgery. “There is a general and
ubiquitous question that people who are
interested in brain function need to grap-
ple with,” says Marlene Behrmann, a psy-
chologist at Carnegie Mellon University in
Pittsburgh. “It has to do with the extent to
which brain function and even brain struc-
ture is concretized or potentially more mal-
leable.” U. D .’s surgery and recovery marked
an opportunity for Behrmann and her col-
leagues to address “one small nugget in this
much, much larger question,” she says.
U.D. is one patient out of many whom
Behrmann and her colleagues are now
studying to assess the brain’s visual sys-
tem’s plasticity—its ability to change—
after undergoing a similar surgery. Unlike
memory or language processing, which
have been explored by many studies of
brain recovery following surgery, “there’s
been really very little work that’s looked
at reorganization or compensation in the
visual system of the brain,” she says.
In particular, Behrmann’s team is inter-
ested in these patients’ ability to recognize
written words or faces because they are
among the most complex stimuli for the
visual system to process. To ease the bur-
den on the visual system, a normal brain
typically splits responsibility for process-
ing words and faces across the occipital
and posterior temporal lobes, with the left-
hemisphere sides of those regions recogniz-
ing words, and the right-hemisphere sides
recognizing faces. “It’s not exactly cut-and-
dried like that, but one or the other hemi-
sphere bears the burden, to some degree, in
each task,” Behrmann says. Given this divi-
sion of labor, she and her colleagues wanted
to know what would happen to U. D .’s abil-
ity to process images on removal, or resec-
tion, of a large portion of the right side of
his brain—and more importantly, how his
brain might compensate for that loss.
In a paper published in July, the team
describes the neurological and cogni-tive development of the boy during the
four years following his lobectomy (Cell
Rep, 24:1113–22.e6). “We decided to pub-
lish that single case ahead of the compre-
hensive group data because it is the first
study that has monitored the change over
time in an individual following a resec-
tion,” Behrmann says. Usually, studies that
assess patients’ ability to recover cognitive
abilities are started many years after sur-
gery rather than just one year afterwards,
as this study was.
When the researchers examined U.D.
13 months after the operation, they found
that the seven-year-old exhibited cogni-
tive skills that were on a par with other
kids his age. “We were really surprised that
this young child learned to read very well
and showed absolutely normal face recog-
nition,” says Behrmann. Consequently, “we
wanted to know: How did the brain orga-
nize itself so that both tasks could be taken
on in only one hemisphere?”
Sifting through neuroimaging data col-
lected on several occasions over the three-
year period following that first examina-
tion, when Berhmann and her colleagues
would ask U.D. to identify words or faces,
the researchers detected activity in a
tiny region of the left hemisphere of his
brain during face recognition tasks. This
unidentified region sat right next to a dif-
ferent, known region, the visual word form
area, that showed activation during word
recognition tasks. Although word recogni-
tion is normally associated with the visual
word form area, face recognition usually
is not processed in this part of the brain.
“It was as if these two little brain regions
were jockeying for position, pushing each
other apart,” Behrmann says. They were
abutting, and only partially overlapping,
but allowed for word and face recognition
in the single left hemisphere, the research-
ers concluded.
U.D. hadn’t regained all visual func-
tions of the right hemisphere, however.
He still was unable to see his left visual
field as a result of the surgery, suggest-
ing his brain did not have the plasticity
to remap the region in the right hemi-
sphere that processes visual stimuli from
the opposite-side visual field. Instead,Engage in the broader conversation
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