Chapter
Eleven
The function of consciousness
Finally, there is the novel process of ‘re-entry’, a dynamic process in which selec-
tive events across the brain’s various maps can be correlated. Re-entrant circuits
entail massively parallel reciprocal connections between different brain areas,
allowing diverse sensory and motor events to be synchronised. The activity of
groups of neurons can contribute to consciousness if it forms part of what they
call the ‘dynamic core’. This is an ever-changing yet highly integrated functional
group involving large numbers of widely distributed thalamocortical neurons
with strong mutual interactions. According to Edelman and Tononi, these princi-
ples provide the basis for understanding both the ongoing unity and the endless
variety of human consciousness.
This theory certainly entails both selection and variation, but it is not clear that it
includes any principle of heredity. In Edelman’s theory, variant patterns are gen-
erated and selected, but there seems to be no mechanism for copying variants to
make new ones. Put another way, there is no replicator. This probably applies also
to Crick and Koch’s (2003) idea of competing coalitions of neurons. Coalitions vary
and compete with each other for dominance, and in that sense are selected, but
they are not copied.
William Calvin (1996) is an American neuroscientist whose theory does include
such copying. He describes the brain as a Darwin machine and sets even higher
standards for a truly Darwinian creative process, listing six requirements, all of
which are satisfied in the brain. Most important is his understanding of copying.
Throughout the cerebral cortex, he argues, are spatiotemporal firing patterns
that represent concepts, words, or images. These patterns depend on the way
cortical cells are wired up in columns, and with both lateral inhibition and lateral
excitation at different distances. The result is hexagonal structures about half a
millimetre across that can be copied or cloned and that compete for survival in
a truly Darwinian process. Imagine a vast, ever-shifting quilt of hexagons, all jos-
tling to survive and get copied, some cloning whole areas like themselves while
others die out. Consciousness is the currently dominant patch of the hexagonal
patterned quilt. This model has not led to further research, but is the kind of prin-
ciple we would need for a truly Darwinian understanding of the brain.
These theories all deal with Darwinian processes within one brain. Dennett’s
Tower of Generate-and-Test shows a hierarchy of ways for brains to evolve by
reacting to the situations they find themselves in: from creatures hardwired to do
only what their phenotypes allow, to creatures that blindly try random options
and learn which ones work best, to creatures that use their imaginations to rule
out ‘truly stupid’ options before trying them. Our last theory of universal Darwin-
ism deals with copying between one brain and another, achieved at the top level
of Dennett’s tower: here culture (from tool use to artistic creations) both requires
and enhances intelligence. Creatures at this level can share information and skills
with each other, and the first steps have now been taken towards creating them
in robot form, using communication between individual robots that have internal
models of both themselves and the world (Winfield, 2017).
MEMES AND MINDS
Memes are ideas, skills, habits, stories, or any kind of information that is
copied from person to person. They include written and spoken words,