controls most of the basic life-sustaining
functions, such as respiration, heart rate
and locomotion, as well as sensory relexes
associated with vision and hearing.
But things are vastly different in the
forebrain, which is so disparate in ish and
humans that it is diicult to ind any struc-
tural likenesses (Fig. 1). Given that their
anatomies are so dissimilar it is not
surprising that their functions are also
different. This is best exempliied by exper-
imental reports of goldish that have had
most of their forebrains surgically removed.
The behaviour of these animals cannot be
easily distinguished from ish with a func-
tional forebrain: they eat normally, swim
normally and respond to danger normally.
They are just as hard to catch with a ish
net in a tank as normal goldish.
In contrast, lobotomised people have
severely altered behaviours. The movie
One Flew Over the Cuckoo’s Nesthigh-
lighted the detachment and loss of spon-
taneity observed in psychiatric patients
following lobotomy, which involves
severing discrete connections in the fore-
brain.
As already mentioned, complex connec-
tions between subregions of the forebrain
are responsible for generating the feeling
of pain. These circuits can be artiicially
stimulated with surgically implanted elec-
trodes, causing people to feel pain. In
contrast, when these circuits are damaged
by ischaemic stroke (a blocked artery in
the forebrain), the sensation of pain can be
lost.
Pain circuits similar to those in humans
are found in other mammals, from mice to monkeys. However,
they are not present in the ish forebrain and can’t be found in
other parts of the ish nervous system. Indeed, no other brain
circuits have been identiied in ish that could take over the
function of these unique pain circuits.
It may be helpful to think of another computer analogy.
Low-end desktop computers lack the processing power to solve
diicult computations because they contain microprocessors
with relatively simple circuits. The only way to perform such
computations is to upgrade to a more expensive computer with
advanced microprocessors that possess more complex circuits.
The ancient science of anatomy has enabled us to look deep
inside the heads of ish and humans and to realise that the ish
brain lacks the necessary hardware for feeling pain. The myth
that ish feel pain has been busted. The catish’s wincing and
slithering behaviour, in response to the Devil’s plucking of
scales, was performed non-consciously using ancient survival
circuitry in the brainstem.
While some people will continue to be disbelievers, the
history of science reminds us that progress is achieved when
we abandon intuitive beliefs about the way we would like nature
to be, and instead accept nature for what it is.
Professor Brian Key is Head of the Brain Growth and Regeneration Laboratory in The
University of Queensland’s School of Biomedical Sciences.APRIL 2016|| 33Illustrator: Marsha Wajer