8 September 2018 | NewScientist | 13NEWS & TECHNOLOGY
EVER felt like you are struggling to
think about too many things at once?
That might be because your brain’s
attention systems are full.
A brain scanning method that
shows how much energy nerve cells
are using has provided support for
the idea that we have a finite amount
of attention available. This offers an
explanation for the bizarre “invisible
gorilla” optical illusion, in which
people focus so much on one aspect
of a staged video that they fail to
see a person in a gorilla suit.
Nilli Lavie at University College
London (UCL) took advantage of a
new brain scanning method, called
broadband functional near infrared
spectroscopy, which was developed
as a way of measuring the brain’s
oxygen levels with a simple headset.
Another research group at UCL
has tweaked the technology so
that instead of oxygen, it measures
the activity of an enzyme inside
mitochondria, the tiny structures
that provide cells with energy. “We
are measuring the metabolism inside
the neuron,” says Lavie.
In her latest experiment,
participants did either an easy or hard
version of a visual task that involved
spotting certain shapes and colours on
a screen, while wearing the headset.
Half the time they were also shown a
flickering chequerboard pattern in the
periphery of their vision.
When the main task was easy, the
brain cells dealing with peripheral
vision raised their firing rates as the
pattern started flashing. When the
main task was difficult, the flashing
chequerboard pattern led to little
increase in neural activity. “You
suppress things you’re not attending
to,” says Lavie, who presented the
findings at a recent UCL Neuroscience
Symposium.
Jan de Fockert of Goldsmiths,
University of London, says other work
has also shown that demands on our
attention from one sense can affect
other senses too. Clare Wilson QBrains at full
capacity stop
noticing things
Inga VesperHIGH prams with canopies that
shield a baby’s head could go some
way towards reducing exposure
to dangerous particle pollution.
By kitting out prams with
air quality sensors and taking
them for a stroll, a team at the
University of Surrey, UK, is
studying how much pollution
babies are exposed to and the
pram designs that are best at
combating it.
The team has found that higher
prams are better, because most
particle pollution is concentrated
in the first metre above road level.
On average, children in prams
breathe at a height of about
0.85 metres, meaning they are
exposed to about 60 per cent
more pollution than adults.
On top of this, particle pollution
is more dangerous to infants than
adults, says Jonathan Griggs at
Queen Mary University of
London, who was not involved in
the study. Babies breathe faster
than adults and they are more
vulnerable to the effects ofpollution because the protective
mechanisms in their lungs are
not yet fully developed, he says.
When choosing the best pram
for defending against pollution,
the weather is also a factor.
Hot summer air concentrates
pollution close to the ground,
making seat height particularly
important. But when the air is
cold, the heat from car exhausts
whirls dangerous particles higher
in the air, after which they
descend. In these cases, prams
with some kind of covering, such
as a canopy or plastic bad-weathercover, can help protect children
from pollution falling down on
them from above (Environment
International, doi.org/cthc).
“There are very few existing
studies to draw conclusive
evidence on which pram design is
best,” says Prashant Kumar, who
led the research. So far he is onlyable to identify broad things to
look for in a pram, but his team
are running further tests until
the end of September, after which
they plan to make more detailed
recommendations.
In the future, it may be possible
to purchase add-on air filter
systems for prams. One currently
in development is called Brizi. The
device consists of a flat headrest
with wings on either side of the
baby’s head.
Air is sucked in on one side,
cleaned, and blown out the other,
creating a bubble of slightly
higher air pressure, which keeps
out particles.
Exposure to particle pollution
damages lungs and can cause
inflammation and long-term
respiratory problems. According
to the UK government’s Clean Air
Strategy, around 340,000 life
years are lost in the country every
year due to pollution.
Designing better prams is only
an interim solution to tackling
pollution itself, says Griggs.
“It’s certainly prudent not to stick
your child next to an exhaust
pipe, but in the end it is not about
protecting babies by technology,
but reducing emissions on roads,”
he says. QPram design can cut
air pollution risk
WEHNER/PLAINPICTURE
“Babies are more vulnerable
to pollution than adults –
they breathe faster and
have less developed lungs”Canopies can shield babies from
swirling car exhaust particles