Figure. The conch Strombas gigas.
Ninety-nine per cent of this giant pink conch is made of a mineral
called aragonite that is a form of calcium carbonate that breaks like
chalk. Yet the shell of the conch resists fractures a hundred to a
thousand times better than the mineral of which it is formed. Nature
has developed a microscopic structure for the conch that surrounds
each aragonite crystal in its shell with a protein that changes the
toughness of the shell by enabling fractures to spread without breaking
the material. In addition the shell has three layers with the “grain” of
each layer perpendicular to the grain of adjacent layers. This
composite cross-grained material gives the conch shell extraordinary
strength.
If Nature expended such effort during evolution to protect the humble
conch, then what effort must have been expended to protect the
workings of the Consciousness of Man?
Coincidentally the brain has three main neuroanatomical
arrangements. First there is the thalamocortical system that networks
the thalamus, the cortex and cortical regions. Secondly, there is a
network of long polysynaptic loops that extend between the cortex and
the cortical appendages. Thirdly, there is the diffuse network of
projecting value systems (the noradrenergic locus coeruleus) that
extends over the entire brain. The projecting value systems network
appears to fire (react) whenever an important event happens such as a
loud noise. When it fires it causes the release of neuromodulator
chemicals that appear to influence the resulting neural response to the
event. The projecting value system may be a way of protecting the
brain against over-reacting to major disturbing events.
The Current Theory of Consciousness
Realizing the complexity of the phenomena of Consciousness and the
added complexity of protective mechanisms that Nature might have
built into the structure of Consciousness it is no surprise that we do not
have a satisfactory Theory of Consciousness.
This situation is not without precedent. Similar situations have
occurred in the “hard” sciences and in the social sciences. For
example, George Uhlenbeck, the co-discoverer of electron spin and
one of the outstanding physicists of the mid-twentieth century, spent
many years trying to develop a satisfactory theoretical framework for
understanding Statistical Mechanics from a microscopic point of view.
He told this author (about 1970) that he felt he did not succeed.
Uhlenbeck had the advantage of a completely known theory of
microscopic particles and a well-known theory of the Statistical
Mechanics of large numbers of particles. Despite these advantages he
was not able to relate the microscopic theory with the theory of the
Statistical Mechanics of a large number of microscopic particles.
Relating different levels of theories such as a microscopic theory and a
macroscopic theory is difficult.
The situation of theories of Consciousness and theories of the brain is
much less favorable. We know the overall neuroanatomy (structure) of
the brain. We have a pretty good idea of how some features such as
vision map to specific brain areas. We have a decent understanding of
brain neurochemistry. We have a lot of data on features of
Consciousness and some ideas on how these features map to brain
features. But we do not have a detailed understanding of the brain.
And we do not have a complete understanding of Consciousness. In
particular we can usually only make qualitative statements about
Consciousness. We don’t even know what the relevant variables are