MAPS: Prof. Greenfield's Science - Shallow Again!

[Peter Webster <vignes@xxxxxxxxx>]

[Posted to the Journal of Consciousness Studies discussion list by Malcolm
Muckle]

To: jcs-online@xxxxxxxxxxxxxxx
Date: Fri, 01 Feb 2002 08:14:25
Subject: [jcs-online] Prof. Greenfield - article re C.
Reply-To: jcs-online@xxxxxxxxxxxxxxx

[note: C = consciousness ]

There is a highly dis-satisfying, imo, article re C. by Prof. - now
Baroness - Susan Greenfield in this weeks (2nd Feb) New Scientist mag.

Prof. G. seems keen on measuring the degree of C., and proposing a
particular model of how it arises, without even a demi-ventricular attempt
to say what it is... but then she is coming at it with a strong
pharmacological approach/bias.

Quote - "My own view is that emotions are the building blocks of C., and
that you can't have C. without some sort of emotion."

There is no article on the N/S website, just the title and byline -
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'm glad someone else thinks this is very shallow science indeed. It is not
a mere simplification for the general reader, but sounds as if it was
written for a 14-year-old: appropriate perhaps for a grade-school textbook,
but rather insulting for readers of New Scientist.
Peter Webster - DrugNews moderator http://groups.yahoo.com/group/drugnews

[the copmpleat massacree follows]

Pubdate: Feb 2, 2002
Source: New Scientist (UK)
Page: 31-33
Copyright: New Scientist, RBI Limited 2001
Contact: letters@xxxxxxxxxxxxxxxx
Website: http://www.newscientist.com/
Author: Susan Greenfield

Sensational minds

--Will the day come when we can run a brain scan or take a blood sample and
say, that's a certain type of consciousness at work? Susan Greenfield
thinks it will. Here she proposes a new way to look at this most subjective
of experiences--

HOW does a wrinkled lump of grey matter weighing little more than a
kilogram manage to think, love, dream and feel such widely different
sensations as raw pleasure and numbing depression? Philosophers, physicists
and computer modellers have been pondering these questions for decades,
wondering how your brain creates your consciousness-your personal inner
world of thoughts and feelings.

Thus far, their deliberations have not been entirely fruitful. My own view
is that we should put this big question-the "water into wine" problem of
how the bump and grind of brain cells translates magically into subjective
experience-to one side for the moment, and concentrate on a much less
glamorous approach. I think we can try to establish a correlate of
consciousness-the particular physical state of the brain that always
accompanies a subjective feeling. If we could do so we may at last be ready
to develop a testable model of what happens in the brain when you are
conscious.

My suggestion is that the depth of consciousness varies according to the
number of brain cells working together at any moment in time. At its most
basic level I am proposing that consciousness is synonymous with raw
emotions, and at its fullest extent with inner reflection and
self-awareness. Consciousness is like a dimmer switch, it grows as brains
grow, but it also varies from moment to moment as neurons are coordinated
into vast but highly evanescent working assemblies. These assemblies are
modified in turn by feedback from the body, and communicate their state to
it. Hence, consciousness, in my view, is also a dialogue between the three
great control systems in the body: the nervous, hormonal and immune systems.

Soon we may even be able to monitor this dialogue, or at least to measure
these assemblies as an index of consciousness, and so perhaps gain a better
understanding of what other people or animals are experiencing. Most
usefully, this model might also suggest new ways to treat mental illnesses,
many of which I see as caused by an inappropriate degree of consciousness
at any one time.

The best way to begin to explain consciousness is to draw up a shopping
list of the features or properties we expect. Then neuroscientists can go
back to their labs and see how the brain could deliver.

First, 1 don't believe we should be looking for one special brain region.
Many regions are active while you are awake, but as you become unconscious,
they all shut down in a fairly uniform way. When someone has been
anaesthetised, there's no one region that lights up or gets extinguished.
There is no single specialised "centre for consciousness".

Secondly, although consciousness comes from more than one brain area, at
any one moment you have only one consciousness. The world seems of a piece.
So we can expand the first item on the list to say that while consciousness
is distributed all over the brain, somehow the activities of the different
regions are coordinated. And if there's no special centre or neurons for
consciousness then the neurons and areas that generate it must do other
jobs as well. The physical manifestation of consciousness must be something
that happens in or to ordinary brain cells at certain times, but not others.

Also on my shopping list is the notion that the more complex the brain the
deeper the consciousness. The idea of degrees of consciousness helps answer
questions such as when a fetus becomes conscious, and which other animals
are conscious. 1 can't see a physical Rubicon when the brain of a
developing fetus changes suddenly, nor any obvious cutoff in the animal
kingdom between a nervous system that generates consciousness and one that
does not. We should think instead of a continuum: a rat is conscious but
not as conscious as a dog; a dog is conscious but not as conscious as a
primate; and so on, Even an ant will have a tiny modicum of consciousness.

If you think of consciousness like this-as something that varies by
degree-there are two interesting consequences. The first is that we may be
more conscious at some times than at others, hence our experience of states
of "heightened awareness", and the conviction that we can "raise" or
"deepen" our consciousness. The second, crucial consequence is that we will
have finally converted consciousness from a qualitative to a quantitative
phenomenon. We can then look for a measure of the depth of our
consciousness as it varies from one moment to the next, and search the
brain for something that contracts or expands with it. 1 think that the
most logical place to look is in very large networks - " assemblies " - of
brain cells.

You're born with pretty much all the brain cells you'll ever have, but as
you mature these cells develop more interconnecting branches. Our brains
are incredibly plastic, and these connections grow and change with every
experience. Babies evaluate the world in purely sensory terms-how sweet,
how fast, how cold, how loud. But gradually these abstract sensations
coalesce into people and objects with meaning and associations. It's these
personal connections and associations that 1 think of as the "mind". The
mind is your personalised brain, which allows you to see the world in terms
of what you have experienced already. Even if you're a clonethat is, an
identical twin-your mind will be unique. You see the world in terms of
things that have happened to you alone.

If we see a familiar person, our visual system activates a "hub" of brain
cells that corresponds not only to the shapes, movements and colours of a
face, but to all the associations set up in our mind by our experiences of
that person. That can all happen without our being aware of it.
Consciousness, 1 believe, is generated as this active, hard-wired hub
corrals huge numbers of other brain cells around it to form a vast working
assembly that lasts for just a trice. The image I have is like throwing a
stone into a puddle, producing ripples of consciousness.

We now know the brain to be capable of forming such highly transient
assemblies. Amiram Grinvald at the Weizmann Institute in Rehovot, Israel,
has shown that in response to a flash of light, as many as 10 million brain
cells become active together, coordinated into a working assembly that
lasts for less than a quarter of a second-exactly the space and time scales
1 think we should be exploring.

The assembly will be slightly different every time. Partly it will depend
upon the size and strength of the stimulation of the hub, but also on the
levels of a variety of chemical messengers - neurotransmitters which change
moment by moment. These transmitters "modulate" the activity of large
groups of cells and mediate arousal levels, your sleep-wake cycle and your
dreaming. In physiological terms, these put cells on "red alert" - they can
predispose brain cells to be recruited into the working assembly,
triggering lots of covert associations.

I think it is the activity of these transient neuronal assemblies that
correlates with the depth of your consciousness at any one moment. To test
the model, let's take some examples of the different types of assemblies
formed and see how they relate to different types of consciousness.

One time you'd expect to see unusually small cell assemblies would be when
you didn't have much connectivity in the first place, as in a young child's
brain. What do we know about an infant's consciousness? One feature is that
their centre of attention varies depending entirely on the sensory quality
of what they're seeing. They live in the press of the moment, in a rather
abstract world with little meaning, reacting to everything in a simple,
emotional way. Infants are like little sensory sponges: they lack any
accumulated experience with which to interpret the world. They haven't yet
forged multiple connections - they haven't yet developed a "mind". Each
burst of brain activity will come from only a small hub of cells, which
will create small, short-lived ripples of consciousness.

This is, I believe, the most primitive kind of consciousness we have, with
a small assembly associated with strong emotions and an immature mind. So
my own view is that emotions are the building blocks of consciousness, and
that you can't have consciousness without some sort of emotion. That's why
I for one don't put much of a premium on computer models of consciousness:
such models focus on tasks such as learning and memory, which an ordinary
PC can do without subjective inner states.

There are times when adults too have diminished consciousness. You would
have small assemblies, as in childhood, when you're dreaming. However, the
reason would be different. In this case you have no strong sensory input,
so there's little to stimulate the neuronal hubs, and you're dependent on
internal residual neuronal activity. This perhaps explains why dreams have
a disconnected, flimsy narrative. At the time they seem very real, with
high emotional content, but in retrospect we wake up and judge our dreams
as irrational with the checks and balances of our cognitive adult minds.

We can chemically alter our level of consciousness, too. So a third
situation in which you might have a small assembly would be if the work of
the brain's chemical messengers was disrupted, affecting the ease with
which the working assemblies formed. Taking drugs such as ecstasy can
interfere with one such chemical, serotonin. And in schizophrenia, levels
of another messenger, dopamine, are effectively in excess. In both cases
the ease with which assemblies form would change, the net size would be
smaller and consciousness would seem childlike or dreamy. People may take
the world at face value, see it in sensory terms and display flimsy logic.

Another time you would find only small assemblies is when you are in a
rapidly changing environment with such competition that the assemblies
don't have a chance to form properly. Fast-paced sports like white-water
rafting, bungee-jumping or skiing would do it, as would a rave.

The opposite of such states would be a large cell assembly, where one would
expect the outside world to seem remote. Your senses would be reduced, you
might feel emotionally numb, yet extremely self-conscious. You would have a
highly logical, perhaps persistent train of thought. These symptoms often
occur in clinical depression. Perhaps depression is due to the
malfunctioning of the chemical modulators, resulting in overly large
assemblies. We know the drug Prozac and related agents influence those
chemicals.

Although my theory seems to predict what to expect in different types of
consciousness, the assemblies of neurons I'm positing do not all on their
own generate consciousness. Assemblies are merely an index - a correlate of
your prevailing inner state. Something else must happen. I believe
assemblies report to the rest of the body, and the rest of the body reports
back to them, and this iteration somehow translates into subjective
consciousness.

Neuroscientists, at their peril, often ignore the fact that the brain is in
a body. We know that feedback from the rest of the bodymost noticeably the
immune system and hormones - can influence our state of mind, and similarly
our state of mind can influence other control systems like our immune
status. And we know that the nervous, endocrine and immune systems are
interlinked. I think the links must be chemical, and for my money peptides
are very good candidates. These substances coexist with traditional
transmitters, but are only released under special circumstances, as neurons
become more active. There are many different peptides, so you would never
have exactly the same amounts or combinations twice. Moreover, we know that
peptides can interface with the immune, nervous and endocrine systems: some
peptides are also hormones, and this puts them in a good position to be, if
you like, trilingual.

The way I see it is that at any one moment, transiently formed cell
assemblies would release a signature profile of peptides into the body.
These peptides influence the endocrine and immune systems, and in return
the systems would release peptides that would determine the size of the
brain assemblies. That iteration of peptides between the three great
control systems of the body is, in my view, what happens when you are
conscious. One day it may be possible to test this hypothesis, by recording
profiles of peptide availability in the blood and trying to correlate these
with the prevailing state of consciousness.

I think at a clinical level this exercise would be useful. It might suggest
new ways of treating conditions such as depression with novel types of
drugs, or of developing non-drug treatments that might drive the formation
of a certain size of assembly and alter the type of consciousness in a
beneficial way.

How this all translates into the elusive subjective inner state of
consciousness is a completely different question, and I'm not pretending to
have answered it. On the other hand, I do think that we can use this model
in the future to design experiments and help us understand depression and
emotions, why people take drugs, and perhaps most mystifyingly, why people
go bungee-jumping.

Baroness Susan Greenfield is a crossbencher in the House of Lords,
Professor of Pharmacology at the University of Oxford and director of the
Royal Institution of Great Britain

Further reading: The Private Life of the Brain by Susan Greenfield is
published by Penguin (2000)

SIDEBAR:

WHAT is the key to the perfect state of mind? Growing up and acquiring an
adult mind brings both curses and benefits. Without it we would only see
the world in terms of infant-like abstract sensory qualities, without
context or meaning. But equally our adult mind can be the kiss of death for
pleasure.

We use some telling phrases - letting ourselves go" or getting "out of our
minds". Whether it's through drugs, fast sports, dancing or loud music, we
enjoy being out of control-the passive recipient of our senses. The word
ecstasy comes from the Greek ekstasis, meaning to "stand outside yourself".

But while the conscious experience may be thrilling, self-consciousness
that you are happy is something that occurs "off-line" once you have
regained your "mind". This fulfilment is as important as passion. The trick
is being able to turn your level of consciousness up and down. If you're
stuck in a deeply nonsensory state, we call it clinical depression. People
with schizophrenia, on the other hand, may be excessively influenced by
their senses and the outside world. An inappropriate switching between the
two extremes might be manic depression. We need to let our hair down and
let our minds go, but we also want more - a sense of fulfilment and the
chance to reflect on pleasurable experiences. For that you need the checks
and balances of an adult mind. A perfect life is a balance between the two
extremes.