14 | New Scientist | 6 November 2021
Field notes ToddlerLab, LondonTHREE-year-old Sophie is sitting
at a low table, trying to build a
house out of large plastic bricks,
as a nearby adult gives gentle
encouragement. It could be a
scene from any nursery school,
but for the incongruous apparatus
that Sophie wears: a snugly fitting
black cap studded with sensors
and sprouting multiple thick, black
wires. It looks slightly sinister,
but the harmless cap is letting
researchers do something that
has never been done before: peer
inside the brains of active toddlers.
Sophie is a participant at the
ToddlerLab, a state-of-the-art
facility at Birkbeck University of
London that is investigating child
development. The wires from the
cap she is wearing run from the
top of her head into two small
recording units tucked into her
backpack. This apparatus enables
the team to image her brain as
she moves around, while a pair
of motion-capture gloves and
16 discrete cameras evenly
spaced around the ceiling
record the movement of
each of her fingers down to
one-hundredth of a second.
Brain imaging has taught us a
lot in the past two decades about
the structure and function of the
brain in sickness and in health, but
most approaches have limitations.
The standard magnetic resonance
imaging (MRI) device is a huge
noisy machine that people
have to lie inside, quiet and
still, for up to an hour at a time.
This means MRI can’t be used
easily on young children or to
study any activities that require
moving around – which are
significant chunks of human
existence.
Now the technology being
used at the ToddlerLab, called
functional near-infrared
spectroscopy or fNIRS, is
changing that. With equipment DAVE
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“This technology is giving
us the first looks at
children’s brains when
they are acting naturally”small enough to sit inside
a lightweight cap, it beams
infrared light through the skull,
so that it is scattered into nearby
receivers, also sited in the cap.
The amount of light that
is absorbed depends on how
much oxygenated blood it passes
through, which gives an indication
of how often neurons are firing
in those regions of the brain. In
other words, it reveals how hard
your brain cells are working,
says Lisanne Schröer at Birkbeck.
“It’s giving us the first looks at
children’s brains when they
are acting naturally.”
That isn’t to say that the work
always goes smoothly. “Toddlers
are not the easiest group to work
with,” says Schröer. Sometimes
her subjects decide they don’t
want to wear the special
“scientist’s hat”, for instance.
“If they say ‘no’, that means no.”
Some of the children who
visit today are shy and cling to a
parent’s legs – so getting down
on the floor and blowing bubbles
into the air is all part of a day’s
work for the neuroscientist team.
Another child, Finn, seems
to hold no fears, but is keenerto build a tall tower than the
house requested. “Every session
is different,” says Schröer.
The project is investigating how
we learn to plan and achieve goals
by breaking them down into
smaller sub-goals, by comparing
children who are 3 and 5 years old.
Once the children are happy
wearing the cap, they are asked
to build a simple house shown
in a video, which means they
need to first build each wall,
then put the roof on top.
Using the motion-capture
gloves, the team has previously
found that when carrying out
sub-goals – such as reaching for
a brick – the child’s non-dominant
hand freezes for a few seconds.
“This suggests they are
focusing on executing the
sub-goal,” says Schröer.
But planning seems to take
place at a different point. The
current study indicates that it
is when children are between
sub-goals that brain activity rises
in their prefrontal cortex, the part
of the brain that is involved in
planning, perhaps because they
are selecting their next task.
At least, this is the case for those
children who complete the house.
Longer-term, a better
understanding of brain
development could help children
who may develop atypically,
such as those with autism or
attention deficit hyperactivity
disorder (ADHD), says team
member Paola Pinti.
The technology has other
uses beyond studying children.
The use of wireless recorders
with the infrared brain imaging
is enabling researchers to
examine adults walking around
in the real world, talking to
others, or in the workplace.
“It opens up enormous
opportunities,” says Schröer.
“It’s a whole new field.” ❚Brain scanning and
motion-capture
gloves reveal how
Sophie sets about
making a house out
of building blocksClare WilsonThe technology letting us peek
inside the brains of children