30 | New Scientist | 18 April 2020
Book
The Idea of the
Brain: A history
Matthew Cobb
Profile BooksIN THE 2nd century AD, Galen
of Pergamon, a philosopher and
surgeon in the Roman Empire,
held a public demonstration in
which he got a volunteer to press
on the exposed brain of a live,
conscious pig. The animal passed
out, but the heart kept beating.
After the volunteer stopped,
the pig regained consciousness.
Fast forward to 1860, when
a Parisian man tried to blow his
brains out with a pistol. Instead,
he shot away his frontal bone,
leaving the anterior lobes of his
brain bare but undamaged. He
was rushed to the Hôpital St Louis,
where a doctor, Ernest Aubertin,
spent hours trying to save his life.
In the process, Aubertin
discovered that if he gently
pressed a spatula on the patient’s
brain while he was speaking,
speech was suddenly suspended.
Aubertin reported that “a word
begun was cut in two”. “Speech
returned as soon as pressure
was removed,” he said.
Eighty years later, Wilder
Penfield, a neurosurgeon in
Canada, was carrying out brain
operations to relieve chronic
temporal-lobe epilepsy. Using
delicate electrodes, he mapped
the least damaging cuts possible.
For patients, stimulating these
regions produced the strangest
experiences. A piano being played.
A telephone conversation. The
sight of a man and a dog walking
along a road. These didn’t feel
like memories so much as
glimpses of another world.
All these fascinating stories
are told in a new book, The IdeaThe ultimate inside story
Thinking of the brain as a machine may be hampering our progress
in understanding how it works, finds Simon Ingsof the Brain by Matthew Cobb,
a zoologist at the University
of Manchester, UK. Here, he argues
that the analogies and metaphors
we use to describe the brain
both enrich our understanding
of that mysterious organ –
and hamstring further progress.Study the brain as though it
were a machine and in the end
(and after much good work) you
will run into three kinds of
trouble, he says.
First, you will find that you
cannot reverse-engineer complex
systems. Take what happened
to two neuroscientists, Eric Jonas
at the University of California,
Berkeley, and Konrad Paul KordingViews Culture
JOHN^ MLUND
PHOTOGRAPH
Y^ I
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Y^ IMAGESmany researchers think of neural
codes as representations of that
stimulus, which is a real problem,
because it implies that there must
be an ideal observer within the
brain, watching and interpreting
these representations. It may
be better, says Brette, to think
of the brain as constructing
information, rather than simply
representing it – but we have
no idea, yet, how such an organ
would function. It wouldn’t be
a computer as we know it.
Finally, we take too much
comfort and encouragement from
our own metaphors. Do advances
in artificial intelligence really
bring us closer to understanding
how our brains work?
Cobb’s hollow laughter is all
but audible. “My view is that it
will probably take fifty years
before we understand the
maggot brain,” he writes.
One last history lesson from
The Idea of the Brain is instructive.
In the 1970s, 20 years after
Penfield’s electrostimulation
studies, Michael Gazzaniga, a
cognitive neuroscientist at the
University of California, Santa
Barbara, studied the experiences
of people whose brains had
been split in a desperate effort
to control their epilepsy.
He discovered that each half
of the brain was, on its own,
sufficient to produce a mind,
albeit with slightly different
abilities and outlooks in each
half. “From one mind, you
had two,” Cobb remarks.
“Try that with a computer.”
Hearing the news brought
psychologist William Estes to
despair. “Great,” he snapped,
“now we have two things we
don’t understand.” ❚at Northwestern University,
Chicago. In 2017, they borrowed
techniques normally used for
studying the brain to take apart
the computer chip that enabled
1980s computers to run games
such as Donkey Kong, Pitfall!
and Space Invaders.
They failed to achieve
a meaningful forensic
understanding of the chip, even
though its makers had a clear
explanation for how it worked.
A second problem, says Cobb,
is the way technical terms lose
their specific meanings. According
to Cobb, neuroscientist Romain
Brette at the Institute of Vision,
Paris, has a particular hatred
for that staple of neuroscience,
the idea of “coding”, first invoked
by physiologist Edgar Adrian in
the 1920s.
Technically, in neuroscience
a code is the hypothetical link
between a stimulus and the
activity of a neuron. Today,Do advances in AI bring us
closer to understanding
how our brains work?“ Study the brain as
if it were a machine
and in the end you
will run into three
kinds of trouble”