This is Your Brain
James KentChapter 09: Psychedelic Information Theory Signals & Circuits: The Human Operating System
Everything you experience, know, think and feel is mediated
by one very essential organ: the brain. The brain is made up of roughly one
hundred billion neurons, and as we have seen, neurons are very complex
structures. But it is the localized groupings of neurons (clusters) and the
intricate ways these clusters interconnect (networks) that make us who we are.
These task-specific clusters of networks are all crammed into a very tiny space
in our skulls, but are vital to all the processing of sense, motor, and logic data
we do at every second of every day. Each section of the brain is wired for its
own specific task, and each section of the brain communicates with other
sections of the brain in very specific ways. When these localized clusters are
all functioning properly, we get the emergence of consciousness, with all of the
waking activity, sleeping, happiness, sadness, excitement, boredom, passion,
and anguish that goes along with it.
For the most part, the macrostructure of the brain is
genetically determined; and at very basic levels our neural wiring is all the
same. But every brain is different, and each region of your brain may have
built-in advantages or disadvantages depending on heredity profiles,
environmental factors, and your gender. All people are different; this is true.
Men are different from women; this is obvious from both brain structure and
behavior. Everyone experiences and makes meaning from the world a little bit
differently, adapting to their weaknesses and playing to their
strengths. That we can agree on anything let alone all interact and co-exist
for so long without complete mass choas is a testament to flexible genetic
design and the stubborn strength of human will. Like a muscle, the brain can
adapt to the burden of the task before it, and when put to the right task it
can thrive and grow. Building complex, industrialized, technological societies
is not a human trait per se, but we developed thumbs and got a better
grip on our tools before some other organism beat us to the idea, so
civilization became a distinctly human domain.
And once the early hominids could manipulate tools, the brain
took off, growing and learning new skills that tool-use made possible. And
before long we were using the same tool-manipulating areas of our brains for
manipulating abstract tools like symbols and concepts, tools that could
allow us to think, plan, communicate, and eventually turn our abstract dreams
into hard reality. All of this was made possible by the brain,its bottom-up
awareness of reality coupled with the top-down control of the body to
accomplish its will. And by flexing this logic-processing organ we have been
rewarded with bigger and ever more complex brains, evolving over the millennia
from crude sense processing networks into layered bundles of parallel,
multi-threaded logic circuitry capable of all sorts of associative reasoning.
Language, art, poetry, music, cities, technology... everything we produce exists
in our brains first as concepts and then as symbols that can be transmitted
from brain to brain, which is the basis of all communication, community,
society, and civilization. And this is all made possible by complex logic
processing circuits that not only allow us to envision the dream, but
also allow us to manipulate tools abstract and concrete for turning
our dreams into reality. Homo sapiens is a mind-manifesting organism:
curious, creative, imaginative, adaptive, resourceful... We are all driven by the
psychedelic impulse in one way or another.
But the psychedelic organism, the human being, did not erupt
spontaneously. The human brain evolved over billions of years, bit by bit,
little by little, and some areas of our brain are much older than others. We
may be thinking and reasoning apes, but at the core of our brains we are still
mostly apes with a few thin layers of human logic networking laid over the top.
And as anyone who has fought in a war or been involved in a riot or other mass
hysteria event can tell you, that tiny bit of rationality that separates us
from the beasts can crumble away in a second with the proper stimulus. We pride
ourselves on our civilized manners and keen reasoning abilities, but when our
backs are to the wall, those higher parts of us are gone and the beast is let
loose. Though we are capable of great feats of logic, it is still the ancient
primal instincts that rule us all.
For nearly a century now, scientists have been arguing about
how much of our behavior is ruled by primal instinct and how much is ruled by
higher-level rational thinking, but only recently has the proper research been
done to show how the different areas of our brain influence one another in our
decision-making processes. While it would be nice to say that everyone behaves
the same way, we now know that everyone responds to stimuli in slightly
different ways, and these differences in response can be directly mapped to
subtle differences in neural wiring. As I said earlier, everyone's brain is
wired in basically the same way, but the extent to which specific synaptic
pathways are strengthened between various brain organs is different for every
individual, based on genetics and conditioning. Some people are very effective
at overriding their primal instincts, and other people are impulsive; other
people wilfully ignore their rational brains and live totally by their
instincts. There are very simple neural correlates for all of these behavioral
types, and understanding the ways in which our brains process reality will help
us in developing a comprehensive model of psychedelic action on the senses, the
psyche, and the self.
Brains Organs and Function: The Schematic
Figure 4: This is Your Brain
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For all its mystery and majesty, the brain is really nothing
more than an elaborate set of signal and logic processing circuits bundled
together in our skulls. But this elaborate network of circuits makes us who we
are; it defines everything about our personality from perception to
intelligence to behavior. In addition to dutifully interpreting sense data, our
brains also filter, modify, and fill-in missing sections of data needed to
create a more holistically pleasing picture of reality that imparts some kind
of relevant information or meaning about our surroundings. This
construction of meaning from raw sense data and the execution of actions
based on that meaning is what the brain is all about. Mediating organism input
(sense data) and output (behavior) is what the brain is all about.
Despite the high level of detail we experience in the world
we live in, the reality we perceive from moment to moment is not hard
data; it is a filtered and smoothed holistic representation formed in our
working memories from a merging of data passed upwards from a series of lower sense
processing organs to our "conscious self", which analyzes data and manages tasks
in the higher cortex. A great deal of the data we receive at any one time is
simply shut out of our conscious minds because it is functionally irrelevant to
our moment-to-moment doings, but that does not mean it is not there or that it
doesn't register in our subconscious somewhere. And as you might imagine, any
change or disruption in the process of filtering and reconstructing reality in
the mind's eye could lead to profound perceptual results, including the profound
enhancement of sub-perceptual reality and/or the profound obfuscation of
anything even remotely resembling reality. So before we jump into the
nitty-gritty of sense data processing and psychedelic action, let's take a
moment to look at the major brain areas and functions to get a general map of
the territory we will be discussing when we apply cognitive theory to the
psychedelic model.
Notes on names of brain areas:
Most brain areas are named by where they are located or what
they look like, but to make it sound cooler scientists do it in Latin. I mean,
you don't want to go calling a specific area of the brain, "That part on the
very front of the brain, towards the top, a little to one side," so instead
they call it the dorsolateral prefrontal cortex, which is Latin for "To
the back and side (dorso-lateral) of the very front part (prefrontal) of the
outer layer (cortex) of the brain." I know they do this just to confuse you, so
I have included this handy little reference to help you find your way around
through the fog that descends whenever Latin is trotted out.
Formal & Functional Terms
Rostral upwards, towards the head
Caudal beneath or behind, towards the tail
Dorsal on the back or upper surface
Ventral towards the belly or lower surface
Medial towards the middle or interior
Basal at the base
Lateral to the side
Ipsilateral on or affecting the same side
Contralateral on or affecting the opposite side
Anterior towards the front
Posterior towards the rear
Superior on top of or above
Inferior underneath
Interior on the inside or in the middle
Afferent carrying signal towards the brain
Efferent carrying signal away from the brain
Anatomical terms:
Stria Any nerve fiber or neural signal conduit
Gyrus Any of the many folded layers of the cortex
Sulcus Any large fissure or groove that separates the areas of the cortex
Encephalon Inside the head
Other areas of the brain are named for the people who
discovered them, and you'll just have to figure those out on your own, but I'll
do my best to keep the science-speak to a minimum here, or to translate the
Latin where it seems appropriate. So let's open the hood and take a look at the
parts, shall we?
The Spinal Cord
The good old spinal cord, it carries somatic signals from the
body to the brainstem and mediates signals essential to tactile feedback and motor
behavior. No organ better demonstrates that signal flow is intimately
connected with sensory awareness and consciousness. If you sever the spinal
cord you lose signal from the body and it disappears from the brain altogether.
Signal flow is awareness, remember that.
The Brainstem & Medulla
A very old part of the brain that houses our primal
autonomic systems, responsible for heartbeat, respiration, hormonal response,
and the basics of vertebrate life. Sometimes called the lower brain, the
reptilian brain, or the animal brain, the brainstem represents a very crude
form of consciousness that is pre-verbal, pre-cognitive, and pre-emotional. The
brainstem is barely self-aware but is able to carry out essential survival
behaviors in reaction to environmental stimuli.
From the junction where the spinal cord hits the brainstem,
a variety of small task-specific organs emerge. First there is the medulla
oblongata (middle round part), then the pons (literally a bridge),
the midbrain (or mesencephalon), and at the top of the brainstem
the diencephalon, which merges into the thalamus and the limbic
system (also known as the emotional brain). Each of these brainstem
areas has even smaller task-specifc organs, but if you see words like medullar
or pontine or diencephalic when discussing various brain
functions, you now know they mean various areas of the brainstem.
All of these structures are vital to survival and the proper functioning of the
brain, but I'll pick a couple of areas to discuss in a little more detail.
First, the medulla oblongata is the most basic element of the working
vertebrate brain, and is probably very similar in structure to the very
first vertebrate brain that came into being so many millions of years ago.
It controls the very essentials of life: heartbeat, respiration, circulation;
it routes primal sensory signals from the brain to spinal cord; it detects
motion and position of the body and keeps us oriented; it mediates some very
basic involuntary responses to stimuli, such as pre-cognitive avoidance
reactions in response to pain, loud noise, and danger; and pre-cognitive
seeking actions in response to hunger and food. The medulla is also where sense
data from the ear and tongue first hit the brain for further routing and
processing, illustrating the point that sound and taste (like touch) can have a
very primal, instinctual, pre-cognitive influence on us.
Pons and Midbrain
The pons and midbrain are still part of the brainstem and
sit above the medulla and contain a variety of smaller organs neuronal nuclei
essential to mediating brain function. Most interesting for our
purposes are the areas that produce the endogenous amines, such as dopamine,
serotonin, and norepinephrine. Serotonin is projected upward from neural
clusters in the pons known as the raphe nuclei in the reticular
formation. The neuronal clusters that send dopamine up into the brain are
located in the ventral tegmentum (on the lower
part of the midbrain) and the substantia nigra (black substance,
so-called since it contains the dark pigment melanin, which literally
contains bundles of indoleamine and catecholamine precursors all linked
together). Norepinephrine (noradrenaline), which is released as a motivator in
response to stress on the body, is also produced in an area of the pons called
the locus coeruleus. Acetylcholine is produced in the pons as well, in
the cholinergic nuclei, and generated upward into the brain, but it is
also produced in an area called the basal forebrain, which is the base (of
course) of the front part of the brain at the top of the brainstem. As you can
see, this area of the brain is essential to mediating mood response, and is
heavily networked with connections from both sensory pathways and neuronal
feedback from other parts of the brain, and manages most of the involuntary
responses our bodies have to both danger (fight or flight) and pleasure (mating
and reproduction).
Diencephalon, Thalamus, Hypothalamus, & Pineal Gland
The diencephalon sits at the top of the brainstem and is the
focal point of a lot of signal action. The major component of this area is the thalamus,
which is like the grand central switching station for the brain, screening and
routing sensory signals from the body, eyes, ears, and tongue up to the higher
cortical areas for processing, as well as receiving feedback from the cortex to
mediate pre-cognitive sensory screening. The hypothalamus hangs off the
front of the thalamus and is another major player in the emotional brain, controlling hunger, thirst, body temperature, waking and
sleeping activity, hormonal response, sex drive, and anger, as well as pleasure and
reward pathways. Since it controls the circadian rhythms of the body
(hunger cycles, sleep cycles, mating cycles, etc.) the hypothalamus is
sometimes referred to as the "internal clock" for the body. Also instrumental
in keeping the body's rhythms in check is the pineal gland. Sitting
right in the middle of the brain between the rear lobes of either side of the
thalamus the pineal gland is sometimes called the "third eye." Once thought
to be a vestigial light sensor and sometimes considered to be the "seat of the
soul," the pineal gland is responsive to light stimulation from the retina and
influences the circadian rhythms of the hypothalamus via melatonin secretion.
All of these areas are central to the functioning of the emotional brain, and
have been widely implicated in the actions of psychedelic drugs.
Limbic System, Hippocampus, & Amygdala
Sometimes called the "emotional brain," the limbic system
comprises a layer of organs and neuronal nuclei that sit roughly between
the higher levels of the brainstem and the lower levels of the cortex. In addition
to the thalamus, hypothalamus, and pineal gland, the limbic system also
includes the cingulate gyrus, the hippocampus, and the amygdala.
The cingulate gyrus is a primitive layer of cortical folds that receives
sensory input from the anterior nucleus (front part) of the thalamus and is
thought to influence emotional response to sensory stimuli within the limbic
system. The hippocampus (Latin for "sea-horse") is located deep in the temporal
lobe and is considered to play an important role in contextualizing emotional
information in response to pleasure and aversion stimulus and the coding of
long-term memory. The amygdala (Latin for "almond shaped") is also located deep
in the temporal lobe and is instrumental in processing fear and aggression as
well as pleasurable response to stimulus. The olfactory cortex (which
integrates sense data from the nose) is also tied intricately into the limbic
system, which we will look at in more detail when discussing the sense of
smell. Of course, organs in the limbic system, which plays a major role in
emotion and memory, are highly implicated in the action of psychedelic drugs.
The Cortical Hemispheres, Lobes, and Specialized Areas
The cortex is the primary logic processing circuitry of our
brains, and consists of a wide membrane of stacked neural cells that is folded and
convoluted to maximize surface area within the tiny space that is the cranial
cavity. These folded and crumpled cortical layers make up the hardware of our
entire conscious interaction with the world. All cognitive sensory awareness
occurs in the cortex; all "thinking" occurs in the cortex; all language and
visual imagination occur in the cortex. The cortex is the playground of the
mind, the very map of who we are, and each tiny fold and surface area of the
cortex has its own specialized processes to handle in the emergent gestalt
that is consciousness. So let's cut this sucker up and see how it works.
The Hemispheres: Left Brain vs. Right Brain
The majority of sense data is passed to the cortex via thalamocortical
projections that ascend from (you guessed it) the thalamus to corresponding
processing areas in the higher cortex. The main mass of the cerebral cortex is
split into two hemispheres (left and right), and like most areas of the body,
these two halves are roughly mirror opposites of each other. It is widely
believed that left and right brain differ fundamentally in the types of
information they process, the left brain being associated with parsing logical,
sequential data while the right brain is more adept at synthesizing intuitive,
holistic patterns within the entire body of data. In truth it is not that
simple, and the two hemispheres interact in a wide number of ways both
specialized and complimentary. There are also massive numbers of neural
connections running between corresponding sites on either side of the cortex,
making it more of a stereo parallel processing circuit as opposed to the
specialized dual-threaded process that a Left Brain vs. Right Brain
model implies. However, lesion studies have shown the Left Brain vs. Right
Brain metaphor is accurate to a point, especially when fine attention to detail
(Left Brain) and wide associative leaps (Right Brain) are needed in language
processing.
The surface of the cerebral hemispheres are generally
separated into four different areas, or lobes, and each lobe is
responsible for specific tasks related to consciousness. Let's take a look at the
frontal lobes first, since they comprise much of the networking that
makes us unique individuals.
Frontal Lobes
The frontal lobes of the cerebral cortex, and more
particularly the prefrontal cortex (PFC, or "front part" of the
frontal lobes) are associated with conscious identity, working memory,
learning, long-term planning, and the executive self, which is the part
of the brain responsible for aggregating sense data and making voluntary
behavioral decisions based on logical processing of those data. While the
prefrontal lobes store short term memory, the inferior frontal region known as Broca's
area is where speech originates both when we speak to others and when we
speak to ourselves (as in internal dialogue or thinking, which uses the
same pathways as speech but without the activation of the motor cortex to make
the mouth move). The frontal lobes aggregate and contextualize sense data to
create our moment-to-moment picture of reality, and communicate via feedback
loops with other areas of the brain to control both voluntary and involuntary
activity. Conscious ideation, visualization, planning, thinking, and
contextualization of self are all frontal lobe activities. It would be a gross
oversimplification to call this area the "mind," but it would not be a stretch
to call it "ego." We will be examining more of the specialized functions of the
frontal lobes and their feedback pathways with other circuits a bit later in
this section.
Temporal Lobes
Of all the brain areas, the temporal
lobes are most associated with the strange and bizarre. These lobes rest
along the underside of either side of the cortex like headphones, and are
responsible for primary audio processing, primary olfactory processing, pattern
recognition, emotional processing (along with the limbic system), and
long-term memory processing (along with the hippocampus). In addition to being
the primary area of interest for audio hallucinations and many synesthetic
components of the psychedelic state, the temporal lobes have also been
implicated in the eruption of spontaneous mystical states via temporal lobe
seizures or artificial temporal lobe stimulation with electrical probes.
This unique trait led to the temporal lobes being dubbed the "God Module" in
the mainstream press around 1997, and popular speculation about religion being
hard-wired into this area of the brain have persisted ever since. Temporal
lobe epilepsy can cause overly religious, mystical, and messianic behaviors
that affect a person for life. No other area of the brain
seems to produce such profound effects. Of course, when we talk about drug-induced
mystical experiences it is important to keep the temporal lobes in
mind. These lobes are implicated as one of the (if not the) key players
in mediating the most sought-after affects of the entheogenic experience. We
will be coming back to the temporal cortex many times when discussing sound
processing, audio hallucinations, and mystical experiences in greater detail.
Occipital Lobes
Sitting on the very back of the cerebral cortex are the occipital
lobes, and what is interesting about the occipital lobes is that they are
the primary visual cortex of the brain. That's right, this area in the
very back of the brain is where sight is processed, much like a movie projector
shining light through the cornea and projecting it from the retina to the back
wall of the cranial cavity. Everything we "see", we see because signal makes it
to this area of the brain; and if electrical activity happens in this area of
the brain, we see it. Of course, this area is primarily implicated in
visual perceptual distortions and visual hallucinations under the influence of
psychedelics, so we will be examining the processes of the visual cortex in
detail later.
Parietal Lobes
The parietal lobes are famous for being both
the primary area for processing the sensation of touch as well processing all
outgoing motor commands. The parietal lobes essentially are the
awareness of the body in the cortical mind, receiving sensation, sending motor
commands, and processing spatial awareness data. This area of the brain also
specializes in the logical manipulation of abstract concepts such as the
numbers and symbols of mathematics which are basically internalized
representations of our physical world, and thus very much like our spatial
reasoning activities. The occurrence of somatic sensation and tactile
hallucinations in the psychedelic state would certainly implicate the
stimulation of the parietal lobes in some sense, though if that were true one
would assume that psychedelics might also have a corresponding effect on
spontaneous motor activity as well. The reporting on spontaneous motor activity
under the influence of psychedelics is spotty surely far less than those
reporting tactile hallucinations so we will look at this dichotomy a little
later when discussing tactile hallucinations and other somatic phenomena.
Is that all?
Believe it or not, we now have our functional schematic of
the brain. Sense data enters through the brainstem, is processed for emotional
and involuntary response in the higher brainstem and limbic system, and is then
passed to the corresponding area of the cortex for final processing and
holistic integration in the PFC. And that's it! Hard to believe such a complex
organism can be deconstructed so completely, but we've covered almost the
entire brain with the exception of the cerebellum, which is at the back
of the brain, behind the pons and under the occipital lobes (visual cortex),
and is primarily responsible for coordinated movement and fine motor control.
We will not be discussing the cerebellum in much detail in this text, but be
happy it is there to record and play back little things (like brushing your
teeth) so you don't have to consciously think of each step of every task every
time you want to do something. Of course there are important little bits and
pieces of the brain I have left out, but I can't cover them all within this
brief introduction. But by the time we are done with this section we will be
very familiar with all the essential bits of the brain implicated in
psychedelic action.
But Where is Mind?
While we have identified the specialized functions of each
of the major brain areas, we have still not identified specifically where
"Mind" emerges. It is tempting to say that Mind is in the prefrontal cortex (or
PFC), the working brain that manages moment-to-moment task processing and
awareness, but the PFC is just the one part of mind, the analytical actor of
self and ego, the "logical homunculus" in the control tower that dictates
conscious behavior. But there is more to mind than that, and our emotions sway
us just as heavily as our logical rationales. The logical mind and the
emotional mind are not two separate things, but they are both part of the same multi-threaded
cascading parallel feedback circuit, which means that mind is the emergent
gestalt of all these networks performing specialized threaded processes in
concert. If you damage one of these areas, the mind is also diminished in some
way. Conversely, if you artificially stimulate one of these areas, the mind is
fundamentally altered in some way. All of these process interact seamlessly
with one another, and they are all responsible for giving us our
"consciousness": both the pre-cognitive and cognitive awareness of the
self interacting in the "now." When these areas are awake, manipulating signal,
and running their processes, Mind is active and alive.
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Tags : psychedelic Rating : Teen - Drugs Posted on: 2005-04-13 00:00:00
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