The June Discover Magazine had an interesting article on Body of
Light (aka "rainbow body") realization. The interesting thing is, now
that they finally duplicated early 50's research on samadhi in
advanced meditators, theorists Stuart Hameroff and Sir Roger Penrose
have come up with a theory for the physical linkage between the
physical structures of the brain, the fundamental luminosity of mind
and Planck scale realities.
http://discovermagazine.com/2007/jun/soul-search
http://discovermagazine.com/2007/jun/soul-search/article_print
As Hameroff comments on his website (italics mine):
In a book titled The Quantum and the Lotus by Mathieu Ricard and
Trinh Xuan Thuan (Crown Publishers, 2001), Ricard (a molecular
biologist turned Buddhist meditator and co-author of the Lutz study)
describes the Buddhist concept of three levels of consciousness,
including the most important “fundamental luminosity of the mind”.
This is a “state of pure awareness that transcends the perception of
a subject/object duality and breaks free from the constraints and
traps of discursive thought.” Moreover this form of consciousness,
according to Mathieu Ricard, can exist independently of the brain,
and in fact pervades the universe. Presumably, the meditative state
marked by enhanced gamma synchrony represents an immersion of the
subjects in this fundamental luminosity. (Such a connection may
possibly be explained through the quantum approach to consciousness.
For example the Penrose-Hameroff model suggests a connection between
brain processes and a fundamental Platonic realm embedded in the
space-time continuum.
Back to the brain. The enhanced gamma synchrony during the meditative
state (as the authors tell us) is most likely due to a) an increase
in the size of coherently responding neural assemblies, and/or b)
increased precision in the coherence of responding neural assemblies.
Before addressing these possibilities, consider the origin of
coherence. Even assuming that cortical neuronal assemblies
interconnected by gap junctions (“hyper-neurons”) are the neural
correlate of gamma synchrony, there are two possibilities for the
coherence. One is that ascending or re-entrant thalamo-cortical
inputs drive the cortical neuronal assemblies, like a piano player
might rhythmically strike keys on a piano. The other is that the
cortical neuronal assembly (hyper-neuron) itself is the source of
coherence, due either to some internal reverberative feedback or
common underlying mechanism in the extended membrane and/or cytoplasm/
cytoskeleton. There are arguments against the thalamo-cortical drive
mechanism for coherence based on delays in chemical neurotransmission
and the slightly varying lengths of thalamo-cortical axons required
to reach appropriate regions of cortex. In addition, thalamo-cortical
drive would mean that the thalamus (rather than cortex) was
responsible for choosing areas of cortex for consciousness (though
proponents of this view point to cortical-thalamic feedback). These
are open questions, though the fact that meditators whose
consciousness is devoid of sensory inputs from the external world
exhibit more highly coherent cortical excitations suggests that
thalamic inputs reduce, rather than promote, gamma synchrony. Thus
both enhanced a) size and b) coherence precision of cortical
assemblies seem likely.
Like most good research, this study raises more questions than it
answers. How is the content—in this case the pure quale of compassion—
represented? Is it in the specific coherent frequency? Is it in the
specific neural regions entrained in the coherent process? Is it in
some finer-grained process? Are the coherence, amplitude and/or
frequency related to intensity of experience?
One could say (I would not) that the gamma synchrony/coherent 40 Hz
corresponding with contentless meditation implied a blank slate,
perhaps like a radio station carrier wave, that the coherent
amplitude increase was due to lack of interference stemming from lack
of cognitive processing. But the trained meditators were conscious—
highly conscious—of the feeling of pure compassion. So my impression,
as suggested above, is that their enhanced gamma synchrony reflected
a release from external (e.g. thalamic) distractions, allowing pure
qualia to fill consciousness. Why gamma synchrony (or any brain
activity) should be conscious is, of course the ‘hard problem’. As
those familiar with my views might suppose, my guess is that
conscious experience derives from quantum mechanisms in cytoskeletal
structures within coherently excited components of hyper-neurons.
These in turn facilitate a more direct absorption in what Buddhists
call fundamental luminosity. My guess is also that intensity of
experience corresponds not only with coherence, but also frequency,
that the 80 to 120 Hz coherence is present in the trained meditators
and represents the highest form of consciousness.
