Turning consciousness upside down: Magic mushrooms and the fractal brain hierarchy
Turning consciousness upside down: Magic mushrooms and the fractal brain hierarchy
Comments on the paper by Carhart-Harris et al (2012) which turns turns conventional wisdom about the brain and consciousness upside down.
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From Stuart Hamerof:
The Oxford scientists used fMRI to study brain activity in human
volunteers under the influence of psilocybin, the active ingredient
in hallucinogenic, magic mushrooms. In a startling surprise
(published in the stodgy PNAS), Carhart-Harris et al found that
psilocybin-induced expanded states of consciousness were associated
with a marked REDUCTION in fMRI BOLD signals, indicating reduced
metabolism, blood flow and neuronal electrical membrane activity.
They found that specific large hubs of connectivity (anterior and
posterior cingulate and medial pre-frontal cortex, thalamus) were
The authors point out that psilocybin and similar drugs act at
serotonin 5HT-2a receptors, found throughout the CNS, particularly
in apical dendrites of layer V cortical pyramidal neurons. 5HT-2a
receptors mediate effects of hallucinogenic, and also anti-psychotic
drugs, and are generally thought to be important for consciousness in
some way. They are metabotropic receptors, meaning they connect to
G proteins and other structures (including microtubules) within the
post-synaptic dendrite, (Psychoactive molecules may also bind directly
Carhart-Harris conclude from their study:
These results strongly imply that the subjective effects of psychedelic
drugs are caused by decreased activity and connectivity in the brains
key connector hubs, enabling a state of unconstrained cognition.
I generally agree, but have two quibbles. The subjective effects are
associated with, not necessarily caused by, the lack of connector hub
activity. Second, the term unrestrained cognition is assumed to
refer to intense, expansive conscious experience (which they capture
nicely in Figure 1 of their article).
But why do brain systems (hubs, and the 5HT-2A receptors)
closely associated with normal consciousness go quiet during
enhanced, more intense experience? If consciousness does not
correlate with electrophysiology, with what DOES it correlate? This
turns conventional wisdom about the brain and consciousness upside down.
Here is a possible explanation.
The brain constitutes not only networks of neurons, but also
hierarchical layers, with self-similar information patterns
represented at various different scales, i.e. fractal-like organization.
The brain has fractal-like structure, known as small-world
networks, with a very few large, and very many small, hubs (like
airports, and the internet). Pribram, Bieberich and others have
said for many years that memory and content of consciousness may
be fractal, or holographic, and many have described altered states of
consciousness as fractal, or scale-free.
Neuroscience (e.g. He and Raichle, Bullmore, vandeVille)
have found scale-free, or fractal dynamics in electrophysiological
recordings, from slow, large scale default mode network switching
(0.1 Hz), to 40 Hz gamma synchrony EEG (about 2.6 orders of magnitude).
In an abstract for the upcoming Tucson conference Toward a Science
of Consciousness www.consciousness.arizona.edu, and copied below,
I suggest that a fractal brain hierarchy extends downward in scale,
from network and neuronal levels, to faster (and smaller in local
scale) levels. Namely, the fractal brain hierarchy extends smaller
and faster into microtubule dynamics, shown to involve a series of
resonances from kilohertz to megahertz (Sahu et al, Nature Materials,
Applying Penrose-Hameroff Orch OR, consciousness occurs
whenever E=h/t (see abstract), and that can happen at any of these
This suggests consciousness can move up and down the fractal hierarchy,
like music changing octaves. Going deeper in scale (smaller, faster)
into, say, microtubule-based megahertz consciousness would involve more
intense experience, more overall brain involvement, and quantum coherence.
As consciousness goes deeper (e.g. into quantum level stochastic
resonance), membranes rest and energy requirements are minimized.
From the network standpoint, it is as if airline passengers shifted
from nearly all passenger being on large, long distance flights between
major hubs, to them all transferring to many, many small, short flights
between local airports (all perfectly synchronized). The large hubs
would be quiet, like they are in the brain on psilocybin.
These deeper layers in the brain, according to Orch OR at least,
would be connected by gap junctions and utilize quantum effects for
non-local coherence and interactmore intense levels described in
Eastern philosophical traditions.
As the Beatles said,
The deeper you go, the higher you fly.
The higher you fly, the deeper you go.
My hat is off to the Oxford team for a magnificent, ground-breaking
courageous study. I would be interested to hear alternative suggestions
for their findings, and/or comments on the fractal brain hierarchy
Orch OR suggestion.
Stuart Hameroff MD
Professor, Anesthesiology and Psychology
Director, Center for Consciousness Studies
The University of Arizona, Tucson, Arizona
(Tucson abstract below 2012)
Fractal Brain Hierarchy, Consciousness and Orch OR
University of Arizona
Fractal, or scale-free structure and dynamics imply systems
with self-similar information patterns occurring across many
spatial and temporal scales. Such systems are found widely in
nature, including the brain. 1) Structure: neuronal dendrites (and
their internal cytoskeleton) have fractal geometry, neurons connect
in nested hierarchies of small-world fractal networks , and grid
cells in layers of entorhinal cortex represent spatial environment at
different fractal scales. 2) Mental representation: memory is distributed
"holographically", and visual imagery in altered states is often
described as fractal. 3) Temporal dynamics: Electrophysiology by He and
Raichle  and others has shown self-similar dynamic patterns repeating
at spatiotemporal scales, e.g. default mode switching (0.1 Hz) and more
rapid EEG (10 to 100 Hz), separated by 2 to 3 orders of magnitude. What
about smaller, even faster scales? Underlying neuronal and synaptic
functions, cytoskeletal microtubules have a series of resonant frequencies,
e.g. roughly 10 kilohertz and 10 megahertz , and gigahertz and terahertz
resonances are proposed. Self-similar dynamics and information
processing in these 6 discrete levels (EEG through microtubule resonances),
each separated by 2 to 3 orders of magnitude, may comprise a fractal brain
hierarchy in which a process supporting consciousness occurs and moves,
akin to musical notes moving through different scales and octaves. What
process? Penrose-Hameroff Orch OR  is the only theory proposing
a specific process resulting in consciousness: quantum computations in
microtubules, each terminated by quantum state (objective) reduction
by E=h/t. E is the degree of quantum superpositioned matter (microtubule
tubulin subunits), h is Plancks constant/2 pi, and t the time at which
reduction and moments of consciousness occur. Recent demonstration of
quantum-like conductance, condensation and resonance in single
microtubules at ambient temperature  strengthens the biological case for
Orch OR immensely. E=h/t, and consciousness, can occur at any layer
in a fractal brain hierarchy. At the layer of gamma synchrony EEG at 40
hertz, t equals 25 milliseconds, 40 conscious moments occur per second,
and E involves superposition of a billion or so microtubule tubulin subunits
(0.0000000001 of total brain tubulins). E=h/t can also occur at deeper levels,
with higher frequency, greater experiential intensity, and more
microtubule/brain involvement. At 10 kilohertz microtubule resonance, E would
involve 0.0000001 of brain tubulins, and at 10 megahertz, E would involve
0.0001 of brain tubulins, nearing brain capacity. Meditation, peak experience
and altered states may involve consciousness (by E=h/t) moving to deeper,
aster, more intense levels in a fractal brain hierarchy.  Bieberich (2002)
Biosystems 66(3):145-164;  Pribram (1971) Languages of the brain,
Prentice-Hall;  He and Raichle (2009) TICS,  Sahu et al (2012) Nature
Materials (in press),  Penrose and Hameroff (2011) J Cosmology 14