Could Tononi’s Phi even help us understand
if a computer, the internet or even a city
can achieve consciousness. Perhaps the
internet or a computer once it hits a certain
threshold might too at some point in the future
recognise itself when it looks in the mirror.
Consciousness could correspond to a phase
change in this coefficient rather like the way
water can change state when it’s temperature
passes the threshold for boiling or freezing.
And if consciousness is actual a spectrum
encoded by this coefficient Phi measuring the
consciousness of a stone to the consciousness
of the human mind who are we to say that
there might not be consciousness beyond
where evolution has got the human brain.
fMRI scans have been done on Tibetan monks
as they are meditating and it seems that their
act of meditation takes them into an altered
brain state that might well be an increased
level of consciousness. The brain appears to
be organised into two networks: the extrinsic
network and the intrinsic, or default, network.
When people are performing tasks external to
themselves like playing a musical instrument
or filling the kettle then it is the extrinsic
portion of the brain that is active. When
individuals are reflecting more on themselves
and their emotions it the default network
that appears to be more dominant.
Marcus du Sautoy is Simonyi Professor
for the Public Understanding of Science
at the University of Oxford.
This article was commissioned and
kindly reproduced for this programme
by the New Statesman
Produced by the Barbican in association with Lumin
The Barbican would like to thank
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Consciousness is part of Wonder:
Art and Science on the Brain
A season to light up the mind with film,
theatre, music, talks and participation in
partnership with the Wellcome Trust
Find out more at
barbican.org.uk/wonder or #wonderseason
The interesting observation is that these two
networks are rarely fully active at the same
time. One side of the seesaw needs to be down
in order to allow the other side to play its part
in allowing an individual to concentrate on
whatever task is at hand. But evidence from
scanning the Buddhist monks during periods
of mediation reveals that they seem to be
able to raise both sides of this neural seesaw
at the same time. The research opens up
the exciting possibility that there are ways to
increase your levels of consciousness. And so
on the 2nd of March as part of the Barbican’s
Festival of the Brain I will be collaborating
with musician James Holden to see whether
we can use music to take the collective Phi
of our audience and turn it up to 11.
Programme note © Marcus du Sautoy
The City of London
Corporation is the
founder and principal
funder of the
Barbican Centre
Consciousness
Sat 2 Mar 7.30pm
Free Programme
Consciousness
What is consciousness? This has to be one of the
biggest unresolved questions on the scientific
books. In the past, the question was the reserve
of theologians, psychologists and philosophers.
Scientists seemed unable to find a way to
question the grey matter between our ears.
After all how can you get the brain to investigate
itself? But that has all changed as will be
revealed as part of the Barbican’s forthcoming
festival in collaboration with the Wellcome
Trust Wonder: Art and Science of the Brain.
Presenters
Marcus du Sautoy presenter, scientist
Vasu Reddy guest speaker, scientist
Mark Lythgoe guest speaker, scientist
Bruce Hood guest speaker, scientist
Band
James Holden electronics / sound design
Etienne Jaumet sax, FX
Tom Page drums
Camilo Tirado tabla, percussion
The study of the brain has experienced a
renaissance thanks to advances in technology.
We stand at a junction not dissimilar to the
moment the telescope provided a way for the
likes of Galileo to probe the outer reaches
of the solar system or the microscope gave
Robert Hooke the tool to see the cellular
structure of a plant. The development of the
fMRI scanner, techniques of transcranial
magnetic stimulation and EEGs have given
scientists a way to ask the brain questions as
never before. And the results are as startling
as they are illuminating. Because one of the
most intriguing proposals to emerge from these
explorations is that mathematics might hold the
key to unlocking the mystery of consciousness.
One of Us
Louis Mustill visual designer
Dominic Parker art director
Tom Debenham
Max Fielden Arron Smith James Healey
There will be one interval in this performance
Mobile phone experiment
[Leave space for 100 words of copy]
One of the powerful techniques in science is
to turn questions on their head. To understand
what makes something conscious one can
look instead at the converse question of what
contributes to things being unconscious.
Every night when we fall into dreamless sleep
our consciousness disappears. So what is
happening in the brain that means that we lose
our sense of self until we wake or dream?
Marcus du Sautoy
In the past it was impossible to ask the sleeping
dreamless brain questions. But new techniques
of transcranial magnetic stimulation or TMS
allow us to infiltrate the brain and artificially
make neurons fire. By applying a rapidly
fluctuating magnetic field to the brain we can
activate specific regions of the brain when
they are awake but more excitingly also when
they are asleep. The question is how does
the conscious and sleeping brain respond
to this artificial stimulation of neurons.
Experiments done by Giulio Tononi and his
team at the University of Madison’s Centre
for Sleep and Consciousness have revealed a
strikingly different reaction of the brain to TMS
during waking and dreamless sleeping. The
first part of the experiment involves applying
TMS to a small region of the participant’s
brain when they are awake or conscious.
Electrodes attached to the participant’s head
record the effect via EEG. The results reveal that
different areas far away from the stimulated
site respond to the stimulation at different times
in a complex pattern which then feeds back to
the original site of the stimulation. The brain is
interacting as a complex integrated network.
The participant is then required to fall asleep
and once in deep “stage 4” sleep TMS is
again applied to the brain in exactly the
same location, stimulating the same region.
Unlike in the conscious state, the electrical
activity does not propagate through the brain.
It’s as if the network is down. The tide has
come up cutting off connections. The exciting
implication is that maybe consciousness is to
do with the complex integration in the brain.
Our gut actually has as many neurons as our
brain yet we don’t believe it is conscious. Is this
because the neurons are not wired to have this
integrated feedback behaviour? Tononi has
even developed a mathematical coefficient of
consciousness which measures the amount of
integration present in a network. Called Phi it
is a measure that can be applied to machines
as much as the human brain and offers the
prospect of a quantitative mathematical
approach to what makes me “me”.