by Rodolfo R. Llinás
MIT Press, 2001
Review by Andrew Bailey, Ph.D. on Oct 16th 2001
This book presents a radically reductive neurobiological view of consciousness
and the self: its central thesis is that conscious thought is (nothing
more than) a global electrical event in the brain, and the self is (merely)
a theoretical 'construct' within our own internal mental map of our environment.
Though studded with interesting insights and intriguing speculation, this
philosophically unsophisticated book does little to render these reductive
claims any more plausible than the reader might already find them. It is
well worth reading, however, as the manifesto of one of the leading workers
in modern neuroscience, summing up in a fairly accessible way several of
his important contributions to the science of consciousness.
Llinás pursues various different themes throughout this book
or rather, he pursues the same theme but at several different levels:
he discusses the emergence of mind at the level of evolutionary history,
at the level of global states of the brain, and at the level of individual
neurons. Llinás is convinced that the mind-or what he calls the
'mindness state'--can only be understood as "the product of evolutionary
processes that have occurred in the brain as actively moving creatures
developed from the primitive to the highly evolved." This evolutionary
perspective helps us to see, Llinás argues, that mindness must be
a global functional state of the brain that allows the animal to move intelligently
within its immediate environment, and does so by creating a simplified,
real-time internal image of that environment which allows the animal to
predict the probable outcomes of its actions. Finally, unlike so-called
'computationalist' cognitive scientists, who think of the mind as being
a kind of abstract functional property of the brain in the same way as
a computer program is an abstract property of the computer which runs it,
Llinás believes that the global brain states which are conscious
thoughts are created by summing together the neurobiological properties
of individual neurons. Individual neurons are in this sense 'proto-conscious,'
for Llinás, and the evolutionary ancestors of our own sophisticated
consciousness were once subserved by the actions of single cells.
So, what is the evolutionary function of the mind? According to Llinás,
the mind just is the nervous system, and the nervous system evolved to
control active movement (or what biologists call 'motricity'). That
is, the nervous system takes in information about the environment and modifies
the animal's internal 'plan' for movement accordingly. Mindness is the
internalization of motricity, and the ultimate function of the brain is
the prediction of the outcome of the organism's movements in a particular
environmental context. As the movement strategies of organisms evolved
in complexity, so too did the nervous system's ability to predict. The
entity we think of as the 'self,' in Llinás's view, is the centralization
of this prediction: it is the bringing together of the brain's various
predictions into a single construct which governs the activity of the organism
as a whole.
How is this mindness produced in the brain? One of Llinás's key,
and most interesting, claims is that a central part of the current cognitive
science paradigm for the explanation of the mind is deeply misleading.
Standardly, cognitive scientists tend to think of the nervous system as
primarily a system for manipulating information received from the external
world--that is, we usually think of the mind as being rather like a computer,
capable of responding intelligently to inputs on the basis of a history
of past inputs. For Llinás, this model is basically flawed. According
to Llinás the brain does not just react intelligently to its environment--instead
(while we are conscious) it is constantly
creating models of sensory
environments, and initiating almost random behaviors, and it is capable
of doing this without
input from the world. The basic state of the
brain, for Llinás, is the dreaming state, a state where images and
impulses are thrown up even without external stimulation by the outside
world. The role of sensory input, when we are awake, is thus not to cause
mental activity but to constrain it--to modify the impulses of the
dreaming brain so that they match external reality in appropriate ways.
Thinking, then, is the modification of a spontaneously generated internal
'virtual reality.' Similarly, for Llinás, behavior is the modification
of what he calls Fixed Action Patterns (FAPs)--"sets of well-defined motor
patterns, ready-made 'motor tapes' as it were, that when switched on produce
well-defined and coordinated movements: the escape response, walking, swallowing,
the prewired aspects of bird songs, and the like." These FAPs, once triggered,
are purely automatic: the role of the mind is not to monitor and bring
about each aspect of these movements, but to determine which FAPs
are allowed to run at a particular moment (shall I fight or shall I flee?)
and sometimes to modify the progress of a FAP to take account of
special circumstances (e.g. resetting our gait when we stumble on a rock).
This makes the brain a much more efficient organ than it would be if it
had to compute every movement of the body at every moment.
Though Llinás never makes it entirely plain just how much, in
his view, thought consists in the running and modification of FAPs, it
is clear that he thinks FAPs are a crucial part of the functional architecture
of the mind. He argues that language-use is a complex FAP, that learning
consists in large part in the adjustment of FAPs, and that emotions are
'premotor FAPs'--impulses to action which do not themselves trigger FAPs,
but which predispose the brain to launch one FAP or another in the presence
of a given stimulus. Brain disorders, also, can be seen as FAP failures:
Tourette's syndrome, for example, is the inability to suppress FAPS, writes
Llinás, while Parkinsonism involves a degeneration in the ability
to trigger FAPs.
For the final piece of the puzzle, Llinás also addresses the
neurophysiological underpinning of the mind--the neural mechanism by which
the mind binds together various inputs into a single 'virtual reality'
model of the environment and 'chooses' which FAPs to allow to proceed.
According to Llinás, mindness is produced in the brain through inter-neuron
communication mediated by electrical activity, and especially by the large
electrical events which involve groups of neurons oscillating in phase.
A key factor is the binding together of multiple, spatially and temporally
spread out brain signals into a single brain state: this is achieved through
'temporal coherence,' probably a coherent 40-Hz oscillation in the thalamocortical
system. Consciousness, in other words, is an electrical storm in the brain.
Whilst many of Llinás's conclusions are each individually plausible--he
makes an especially good case for his view of the 'dreaming brain'--the
resultant picture is ultimately rather unsatisfying. Llinás is never
able to make it fully clear just why he thinks the neural mechanisms he
points to are conscious states: why they feel like something rather
than nothing. For example, merely noting that large arrays of neurons can
be coordinated through a 40-Hz phase oscillation does little to answer
the really interesting question of consciousness--why should 40-Hz oscillation
sometimes feel like the taste of apricots or a deliberate decision to go
to law school, when, say, 25-Hz lock-step oscillation feels like nothing
at all? Like so many contemporary books which purport to provide 'theories
of consciousness,' I of the Vortex is a useful starting point but
falls a long way short of an actual theory.
© 2001 Andrew Bailey
Andrew Bailey, Ph.D.,
is an Assistant Professor of Philosophy at the University of Guelph, Ontario.
He works mainly in the philosophy of mind and metaphysics.
This review first appeared online Sept 1, 2001