FROM CHAPTER 4 - FORTIFICATION

OF THE F-MODEL OF DREAMING

It’s tempting to conclude that the why of all life is: to reproduce. To multiply. Seed sowing. Freud was hooked on this conception of being, and he reduced everything to the sexual libido drive. There is no denying the importance of sex— that is, if we are discussing the perseverance of a lineage. However, what if, in the vast predominance of moments across a life, there are other things going on, besides erotic desire? What animals and machines and gods are predominantly concerned with is this: remaining whole, persevering in a Cosmos seemingly intent on ripping us apart. Sexual union and multiplication have a role in this, and so do things like fortifying your own spot on the frontier.

We have a sense of what belongs to us—right and justly—and what does not: these are our domain boundaries. We also have an ever-present need to protect the perimeter, and to do so, we devise walls and fences around our family, around our resources, and around our Work, and we also contrive shields surrounding our ideas and our ideals. And, for all we encompass, our borders include gates and doors, as well— enabling alliances, and even a means to escape our own preconceptions, if need be.

It is not enough to just be. To remain in this thing, we must earn, and then defend. Fortification is the long-game. This was true even before sexual reproduction was part of what biology did. Prokaryotes, including the Archaea and Bacteria still around and within you—you Eukaryotes—are each an individual living entity, and this is only so because they maintain dynamic boundaries. Boundaries—defining structure—exist within organisms as necessary preconditions for the emergent behaviors which the organisms may exhibit.

In David Byrne’s multi-media “book”— Envisioning Emotional Epistemological Information (2001), the R&R Hall-of-Famer states that organization is content.[1] The way that a thing is structured—say, the brain—tells us much about how it performs. The organization of the brain does seem responsible for how it operates, even if the fine details of its processes may never be fully encapsulated. Starting off as a neurologist before devoting himself to psycho-analysis, Freud had an understanding of where neuro-science was heading. "We will picture the mental apparatus as a compound instrument, to the components of which we will give the name of 'agencies,' or (for the sake of greater clarity) 'systems’” (1900, p575).

With a low-resolution purview, we notice the human think-box is composed of various modules, or sub-structures. A little finer-grain, and we see a discreet separation of neural cell-types. What looked like a labyrinthine-coralesque-yet- basically-homogenous arrangement, from afar—such as the outer rind of the cerebral cortex—is actually a functionally separate plurality of regions, each responsible for particular chores (even though all work together for your benefit,

ultimately). The brain is layered, like an artichoke, or a lotus— each petal a module, all having evolved into roughly concentric, Fibonacci-friendly layers, spiraling out from the core. Lo, we are not vegetables. To build fluid concepts— for sustaining us along disorienting discovery journeys—we draw up analogies from ground already known. Sigmund liked to compare the human brain/mind to the Aurelian Walls.

THE AURELIAN WALLS. Despite the peace and prosperity within Rome, which defined the period known as the Pax Augusta, following a thwarted barbarian attempt to take it, Emperor Aurelian had walls constructed around the great city. The Aurelian Walls were built atop the Servian Wall, a prior incarnation of Roman defensive barrier, 12-feet thick at the base. There were even walls which predated and underlaid the Servian, though recalling those would take us into pre- Roman times.

The Servian Wall was made from local volcanic rock and was situated to take defensive advantage (and minimize natural disadvantages) of the landscape. The Servian Wall successfully defended against Hannibal—through its formidable appearance, if for nothing else—as Hannibal decided that overcoming Rome wasn’t going to happen. Centuries later, when Aurelian commissioned his Wall, the citizens of Rome, themselves, completed the massive project. Aurelian was fully tapped of manpower, engaged in battles elsewhere.

Time and resources were saved by accommodating already-existing structures into the Aurelian Wall, including an amphitheater, a pyramid, and an aqueduct. In 275 AD, the completed wall created a 12-mile circumference, forming an impressive deterrent to would-be attackers and sackers. Over time, the Aurelian Wall was fortified, and in the fourth century was doubled in height to 52-feet. But, why was that first pre-Servian wall put where it was, in the first place? Because: That was a good place to land.

We still don’t know if Romulus was really a founder of Rome, or, if Rome invented Romulus as its founder, after the fact. Rome, and Romulus, may both be named after Rumon, an old name of the Tiber River, where Aeneas landed after fleeing Troy. Mythologies aside, the city that would become Rome was perfectly positioned near the Mediterranean Sea and the Tiber’s banks, almost ensuring that a trading port would emerge there during the age of men.

Whoever it was that really got things going, the people who became Romans turned out to be genius at adopting, adapting, and improving the technologies and concepts of those traders with whom they came into contact. And that Wall atop a wall, atop rock and earth circumscribing Rome maintained strategic use well into the 19th Century AD. The only time it really couldn’t perform its defensive function was during Rome’s civil wars. You might say that the Wall built itself, or, that the Roman will—the spirit of Rome—willed the Aurelian Wall into existence. For defense. As a symbol. To define a space, and a people. Whatever we say, it is

assumed that (like Rome itself) the Wall was not built in a day, nor haphazardly— not in material nor location. Now, let’s dig into the human brain...

BRAINS. Some say that chimpanzees are humans’ closest animal relative. What a moral conflict it must be for many a researcher, who, seeking insight into the human brain, are willing to dig into the skull of a different primate—for the value of what might be gained to humanity—while maintaining the belief that this other creature is almost human, as well. This is not to be speciesist, but we aren’t the same creature, not even close (and that is not endorsement nor admonishment of “animal research”). The thing about genes is that a very few additional or alternate versions of them, between genotypes—despite sharing thousands of other genes in common—can result in dramatically different organisms, with vastly disparate phenotypes, or physical forms.[2]

The average adult human brain weighs about 1400 grams (a little over 3- pounds). The average adult chimpanzee brain is under 400g (or, 368g for female chimpanzees, and 405g for males). The divergence in growth patterns between humans and other primates begins early in life. Measuring with 3D ultrasound, chimpanzee fetuses were only half of the weight of human fetuses by 16 weeks after conception (Sakai, 2012). Even after birth, our trajectory continues to veer from the chimps. The human brain expands three-and-one-third times its birth weight by adulthood, while the chimpanzee brain—born smaller to begin with— increases by only two-and-one-half times its birth weight (de León, 2008). Our brains have similar modules as the chimpanzee brain, but some of ours are much larger, and specializations have evolved in each species. Though this is not unique to humans or primates, it could be said— the deeper into the brain we drop, the farther back we journey into our evolutionary past.

MODULES. Functionally, there are regions of the brain—like tightly packed networks—which change little between early adolescence and early adulthood, although these modular specificities appear to diffuse somewhat later in life (Fair, 2009). Modular connections in the brain become increasingly solidified during the first few years of development, and this follows a similar trajectory across humans. Rather than have a brain which develops into a random web of relationships, what we have instead appears to be the result of time-tested selection; this is economic- ecologic thrift. During our long competitive evolution, these brains etched deep furrows behind the field-of-forms’ brow, despite—or by virtue of—cycles of pestilence, ill-will, and irresolute climates.

Being the new kid in the world, most of our novel modularity is really just refinement of control mechanisms— the overlaying of new circuits atop more primal networks. This is not to say that the resultant abilities made possible with the human brain aren’t qualitatively different from earlier iterations. What has emerged with us is a quality of being which surpasses any predictions availed by

summing its pieces. We don’t just have more brain—merely more forebrain or before-brain—from a functional perspective, we have a whole new kind of brain. A multi-faceted, multi-functional, multi-storied brain. It’s made of old stories, really, told in new ways, given novel twists. But don’t get it twisted— as Pinker replied to Chomsky in their ongoing language debate, “Just as the flying fish is compelled to return to the water...human brains might, for all we know, be compelled to contain circuits for Universal Grammar” (Pinker, 1997). Pinker was suggesting that, perhaps, in order for a brain to develop to the complexity ours has, language circuits are a natural requirement. Big brains, conceived of in this way, must be capable of taking stories in, and of making a story spin.

CONCEPTION. In a cosmic stroke of fortune (whether it was good or bad will be revealed in due time), two gametes—one a tiny squirmy swimmer, the other an enormous and perfect sphere—recognize each other. The seaman is allowed to penetrate the sphere, and the forms from Photo 51 are fused into a novel arrangement; the Earth has been fertilized, and your story is conceived. Spelled as if already having an ending in mind, you are now a one of a kind, one-celled zygote. Your single double-helix splits for the first time, and your walls constrict at the middle, like a relentless belt, cleaving you into two hemispheres. Each nucleic duplicate chooses and rushes for a lobe, and soon—one day after conception—you have become two cells.

Mitotic divisions begin to speed up, and the two cells become four, four become eight...on day three you are a 16 cells-old ball of balls, and your multiple DNA strands are replicating every eight hours. At first, your overall size doesn’t increase, because the cells are smaller for each successive generation and continually pack tighter together. And then, you expand. Sixteen days in, and your neural plate begins taking shape, and by three weeks, most other organs begin forming; at six weeks, that neural plate has become a cellular-tube and forms three bulges— the beginnings of the hindbrain, the forebrain, and the midbrain, between. These three lumps differentiate into all of the modules of your brain, with the spinal cord and peripheral nervous system tailing behind. A first fissure begins to indent the dorsal lump, and the two major brain lobes start their respective journeys. Twelve weeks after conception, the corpus callosum begins to form.

From the core of the developing neural bulges (these hollow-centers will later become the brain-bathing ventricular system), the principle neuron progenitor— the ventricular zone (VZ)—radiates brain cells to their destinations. Neurons proliferating in the VZ are guided by glial cells along their migration, building the brain from the inside-out. The deepest of the cerebral cortex’s six layers is laid down first, then the second above it...and when the neurons are all in position, the VZ and most other cell-generating zones fade away.

FACTOTUM. A factotum[3] is one person—or thing—responsible for multiple jobs. The cook who is also the janitor, who also takes care of the gardening and is in charge of the deliveries and public relations and is a single parent. Or Buckaroo Banzai, who was a neurosurgeon and rocket-car pilot and band leader, particle physicist, and comic book character...a factotum. The mind is the factotum that somehow does all of those things that you do, that you couldn’t possibly do by yourself.

Ever since the idea of “mind” could be abstracted, humans have probably wondered where—if a central point exists—they really are. Called soul or spirit or God or Self, some have considered a spot on or in the body, a place where the God contacts and mingles with our dense plane. Descartes proposed this point of animating contact was in the pituitary, for example. Where is the Homunculus, the little guy at the controls making the decisions, the avatar of “I” in the brain? I don’t know, maybe nowhere, but we do have homunculi, plural. Cortical homunculi. These are neuronal structures in the brain corresponding to various envisages of ourselves. Plural. There is a map for our muscular system. There is a map of the body represented as tactile receptors (of each kind). And there are many retinal maps, with amazing geometric neural arrangements that, like all of these maps, are actually configured in patterns corresponding to the the real-world things being represented.

You couldn’t look at a cortical map as it actually exists in the brain and see an outline of yourself, or even one approximating the famous homunculi representations of the primary sensory and motor cortices made famous by Penfield and Jasper (1954). This is because there is a pattern of overlapping neurons and micro-circuits responsible for showing you, let’s say, “left index finger is flexing” and “left arm is extending.” These perceptual concepts contain overlapping elements (spatially, temporally, functionally); so, the cortical “maps” are not like maps on flat paper, rather, they are dynamic patterns of related activity, sharing nodes of basic representations which our perceptual forms are composed of.

NEO — FOREBRAIN. The cerebral cortex is the convoluted bark of the brain, wrapping all of the other core structures, and, together with the basal ganglia and diencephalon, makes up the forebrain. Ninety-percent of the human cortex is “neocortex,” including the primary sensory and motor areas, and the “association” regions (which are in effect extensions of sensory and motor areas, with many interconnections). The remaining cerebral-cortex is mesocortex, or paralimbic region, made of the cingulate gyrus, orbitofrontal cortex, and friends.

A larger neocortex—particularly amassed in the prefrontal cortex—is the most obvious differentiator of primates from other mammals and is especially apparent in humans. Certain neocortical regions, even prefrontal, are shared by most mammals—e.g., the orbitofrontal cortex—while other regions are unique to

primates, including the lateral prefrontal cortical areas (Zhang, 2011). The larger size and modular complexity of the human prefrontal cortex—of all our features— is the most distinguishing anatomical characteristic of the human creature (Johnson, 2009).

THE TWO HEMISPHERES. The neocortex and mesocortex have a six- layered structure, unlike the allocortex (which includes the primary olfactory cortex, AKA paleocortex— which has one to four layers). However, from the outside looking in, the most obvious subdivision of the cerebral cortex is not its layering, for we could only see the outermost strata, but rather, the two cortical hemispheres. Each cortical hemisphere contains the same number of neurons, though each side retains particular roles. For instance, the left cerebral cortex—in most humans—is where the speech-specializing centers are located (Wernicke’s and Broca’s Areas) and it is in this lobe where much of the processing is performed from which we identify our “humanness.”[4]

THE FOUR LOBES. Each cortical hemisphere is differentiated into four lobes: frontal, parietal, temporal, and occipital. The frontal lobe, behind the forehead, is separated from the parietal lobe—posterior, or behind it—by a fissure called the central sulcus. At the back of the frontal lobe, kissing and running along the central sulcus, is a gyrus called the primary motor cortex (PMC). In front of the PMC and separated by a sulcus called the precentral gyrus, are the premotor and supplementary motor cortices (SMC).

Moving farther forward, or anterior, from the SMC, along the frontal lobe, we arrive at the prefrontal cortex, which includes the dorsolateral prefrontal cortex, the orbitofrontal cortex, and the anterior cingulate regions. “Lack of perseverance”—an inability to constrain one’s behaviors over time—has been positively associated to interactions between the dorsolateral prefrontal cortex and the right inferior frontal gyrus and “lack of premeditation”—weak forethought— has been inversely correlated with contributions from the occipital cortex (Golchert, 2017). These functional circuits overlap with “bilateral dorsolateral prefrontal and bilateral occipital regions of the multiple demand network,” a broad system “implicated in the general control of thought and action.”

Behind the primary motor cortex, posterior to that central sulcus, and designating the start of the parietal lobe, lies the primary somatosensory cortex. Using eye signals—within lucid dreams—as time markers, fMRI showed a match between dreamt hand movements and increased activity in the sensorimotor cortex, suggesting that the dreaming and waking brains use the same processing networks when perceiving body movements (Dresler, 2011).

VISION. Head farther back—posterior—from the somatosensory cortex, behind the parietal lobe, and we reach the occipital lobe, including the primary

visual cortex (V1), or, striate cortex, so-called because it is striped. V1 has been known to exist ever since Korbinian Brodmann identified it (as Area 17), in the early 20th Century. Though we share the same number of neurons in V1 as in primates like rhesus monkeys, ours are massive and result in this region being three-times larger than the monkey’s (Gazzaniga, p663). With eyes closed, V1 shows little activity, but, when we imagine imagery or “call up a visual memory,” we can activate visual association cortex, around it (p77). The occipital lobe is predominantly hidden when looking from the outside-in, its bulk mostly situated between the two cerebral hemispheres. Surrounding V1 is the extrastriate cortex, home of the secondary and tertiary—and beyond—processing areas for visual perception.

When we rotate 3D images in our mind, we activate the same “or similar” cortical areas as we do while wide awake and watching images rotate (Cohen). It should be clear as air that in certain non-awake states (i.e., dreaming), many perceptual faculties are fully functional. Yet, of course, these overlapping states are not the same.

BLINDSIGHT. Visual perception is eliminated after sustaining damage to corresponding regions in the occipital cortex, resulting in what is called cortical blindness. Sufficient damage to V1 invariably leads to cortical blindness, and also to loss of visual dream imagery (Ffytche, 2010). The eyes may remain intact and continue to send visual information to the brain, even as particular visual domains, like color processing, or spatial-positioning in the visual field, are no longer perceived consciously. When some of the functional abilities of vision remain “in the absence of conscious perception,” this is known as “blindsight” (Weiskrantz, 1986). When participants with total cortical blindness on both their left and right visual fields were asked to make “yes” or “no” choices on the position of visual patterns—given auditory feedback when making correct choices—performance improved despite subjectively remaining unable to “see” the patterns (Trevethan, 2012). Even though there was no conscious perception, at another level, perceptions were still being received.

Traveling along the outer cortical surface, below the frontal and parietal lobes—separated by the lateral fissure—but anterior to the occipital lobe, is the temporal lobe. The temporal lobe consists of three gyri stacked upon one another, running from the anterior to posterior of the lobe, with the superior temporal gyrus (STG) and inferior temporal gyrus forming the northern and southern borders, respectively, and the middle temporal gyrus situated in between. Primary auditory cortex, or A1, is located on the STG. A1 is surrounded by the auditory association area, A2. The well-ordered representation of auditory frequency inputs are arranged in “tonotonic maps” in the auditory cortices. In fact, it’s all maps...and associations between maps. (Any neocortical territory, not strictly sensory or motor cortex, has been called association cortex.)

INSULA. Deep within the lateral sulcus separating the parietal from temporal lobes, is the insular cortex. The anterior insula receives input from the thalamus and amygdala, and also shares circuits with the orbitofrontal cortex and areas of the occipital and temporal lobes. The posterior insula also receives input from many thalamic regions, and is also directly connected, both sending and receiving information, with secondary somatosensory areas.

Regions of the prefrontal cortex inhibit excessive amygdala activity in healthy, waking brains—so long as conditions remain “civilized”—but “this relationship was diminished in individuals with posttraumatic stress disorder” (Sripada, 2014). Compared to controls who did not suffer from the disorder, veterans with PTSD exhibited more connectivity between the insula and amygdala.

MONKEY BRAINS. In biology, a homology is a gene, structure, or behavior which is shared between species because it originates from a common ancestor— such as a monkey paw is homologous with a batwing. Things that seem similar but were arrived at independent of one another—such as a batwing and a dragonfly wing—are homoplastic to each other. The “implication” in convergent evolution— when similar structures with similar functions evolve in separate lineages—is that there are “limited and constrained rules” which constrain nature, and even evolution (Gazzaniga, p648).

A “derived trait” is a feature that is unique to a group or species. One derived trait—also a homology, in two otherwise contrasting species—is the echolocation of dolphins and bats, brought to them by an enlargement and adaptation of the inferior colliculus in the midbrain (where, in humans, integration of horizontal and vertical audio signals position sounds in space). When a structure of the nervous system once served a particular function, but then changes and performs a new role, this is called exaptation. The oldest module of the forebrain is the primary olfactory cortex (POC), and a case could be made that much of our perceptual palette is mutated and adapted transformations of olfactory circuitry.

POC. Located at the bottom of the cerebral lobes where the frontal and temporal cortices meet, the POC is connected at one end to the olfactory nerve, which itself travels to the olfactory bulb, the glomeruli, where sensory receptors (of which there are 1000 types) in the nasal cavity make direct molecular contact with the world and then send their signals into the interior. Leaving the POC, olfactory information is sent directly to the orbitofrontal cortex, bypassing the thalamus— the only sensory system to enter forebrain networks without prior thalamic modulation. All mammals have homologous orbitofrontal pathways, and in the human, this region “may have expanded and become prefrontal cortex” (Gazzaniga), and along the way exaptated and differentiated into several major modules, with a galaxy of intertwining circuits betwixt.

ORBITOFRONTAL. The orbitofrontal cortex is located in the frontal cortex, right above and behind the eyeball socket ridges. The posterior orbitofrontal cortex (pOFC) is involved in processing emotions, and in modulating other excitatory modules. This governor helps with “flexibly shifting focus and adjusting emotional drive.” In creatures like us—primates—the amygdala sends “dense projections” to the pOFC, “cooling” hot affect into effectual plans, by sharing this information with various other cortical and subcortical regions which can ration things out (Timbie, 2014). Using rats, the excitatory neurotransmitter glutamate was extracted from the orbitofrontal cortex during waking, non-REM, and REM sleep. Corroborating imaging studies, the orbitofrontal cortex was found to be more active in REM sleep—compared to both non-REM sleep and also the waking conditions—as measured by glutamate saturation. (Lopez-Rodriguez, 2007). One insinuation from this is that during REM dreaming we neccesitate a lot of emotional cooling.

BROCA’S AREA. Another “highly derived” area of the human cortex is Broca’s Area, a primary region involved in language production. This area, though qualitatively unique in humans, may in fact be a co-opting and amplification of motor regions which were, in our ancestors (and still in other existent species)— less gaudy cortical maps, representing “the face and oral structures in the premotor cortex,” as well as similar regions in the primary motor and primary sensory cortices. The language centers of the brain are mostly unilateral, on the the left hemisphere in right-handed people; the right sound-field is processed in the left lobe, so, in this way our language areas are on the side of our “good ear.” Of course, Broca’s Area didn’t evolve in isolation, and to compensate for all that vocal- synthesizer capacity, communication pathways co-developed between itself and Wernicke’s Area, an auditory processing region derived into a super language- receiver (Gazzaniga, p650).

CORTICAL LAYERS. Neocortex is six-layers deep. Some cortical regions include strata that are visible to the naked-eye, like the line of Gennari, a white striation in the visual cortex where fatty axons arrive from the thalamus. Most of the layered-differentiation wasn’t apparent until scientists like Brodmann stained cerebral sections and examined these under microscope (1909), revealing various types of pyramidal and stellate neurons in ordered arrangements.

The cortical layers are numbered from the top down, so that the outermost is Layer I, the one below is Layer II, and the deepest layer is VI— though they do all get “laid down” during development in reverse, from the inside-out. Layer VI— the deepest—receives signals from the thalamus, and also sends signals, both inhibitory and excitatory, to those reciprocating neurons in the thalamus. Layer V neurons send axons down to subcortical regions, mainly to circuits involved in

voluntary motor control. Layer IV receives input from the thalamus and also from other cortical layers, and Layer III receives primarily inter-hemispheric transmissions from across the brain’s bridge. The second and the top-most layers are harder to classify, involved as they are with a lot of cortico-cortico associative processing, though Layer I also receives thalamic innervation.

Not only is the cortex set-up as strata, it is also composed of columns— in many regions there are functional relationships between neurons that are vertical neighbors on various floor-layers. The layering and culmination of the human brain display an order and complexity unsurpassed in the known biological world. Still, there may be other idiosyncrasies—like the spines on our dendrites appearing to exhibit unique properties[5]—which suggest it is not only the number of neurons in a brain determining its capacities, but also the specializations evolved into each lineage’s neurons and circuitry (Shepherd, 1999).

BELOW THE SURFACE: THE LIMBIC SYSTEM. Beneath the cerebral cortex lies the limbic system. Limbus, in Latin, means “border.” The limbic system surrounds and borders the brain stem, and includes the cingulate gyrus, hypothalamus, anterior thalamic nuclei, the hippocampi, and the amygdala. The limbic modules play their mutual roles in emotional processing, long-term memory processing, motivation, and that most ancient of systems— olfaction.

REPTILIAN CORTEX. One wet day, by chance happening or will—I forget which—an animal was born who could develop, as a child, outside of the water world. Vertebrates could now learn about being land creatures. That was 320- million years ago, and early on, the descendants of this new edition split in two directions— the “little” lizards and snakes, still with us, and the Archosauria, or, dinosaurs and birds,[6] and turtles and gators and ‘crocs, some no longer around, others still well and sound. When the lands of Earth were all one—Babylon-like— 230-million years before today, the “terrible lizards” roamed Pangea and swam in the one ocean around it. The dinosaurs reigned until 64-million years ago, when fire rained from above and the sky blackened in the aftermath, for months on end. But we don’t need to build Jurassic ParkTM to get an idea of what the dinosaur brain was like.

All mammal brains resemble one another to a great extent early on in fetal development (and then decreasingly so as “birth” approaches). What appears to be occurring is that the developing brain proceeds through a re-enactment of the evolutionary play each time a life is conceived, building-up newer upon older structures, culminating in a member of whatever species the new being belongs to. All of the major mammal brain regions can be found in reptiles; these homologies appear to be conserved—and adapted—structures, “including the cerebral cortex.” The mammalian cerebral cortex[7] began, long ago, when sauropsids split from the proto-mammals, the therapsids, as a takeover of a pallial brain region.

The reptile cortex contains three layers, and it appears that the medial reptilian layer corresponds to the additional cortical strata-strategies built-up in mammals. Though behaviorally “simpler,” reptiles do exhibit complex problem-solving skills, and many engage in involved-parenting and pair-bonding (families).[8] Reptiles can also solve and recall mazes, a skill we assume requires something like a hippocampus, for integrating various sensory clues. When the medial cortex of reptiles and the lateral palliuminto of goldfish were experimentally damaged, they failed to complete mazes they had already learned, though they still “understood” which cues signaled for them to search for treats; a control group of animals navigated right to the goal, as if the story[9] were fresh and clear.

AMYGDALA. In Ancient Greek it was ἀμυγδάλη. In Latin the word for almond is amygdala. And the brain region which resembles this tree nut was named after it. The amygdala is notable in sleep and dream research because this module is most active during REM— firing rates of pyramidal cells in the amygdala are even higher during REM sleep than when awake (Girardeau, 2014).

The bed nucleus is a limbic structure which receives input from the amygdala and—acting as “a constituent of the extended amygdala”— in turn projects out to hypothalamus and brainstem areas (Kodani, 2017). The bed nucleus may mediate how the amygdala influences autonomic responses to perceived threats, and although it may not play an important role in the Conscious processing of threatening stimuli, the bed nucleus appears to mediate “slower-onset, longer- lasting responses that frequently accompany sustained threats” (Walker, 2003).

Stress—as an accumulated physiological response to perceived threats—can shrink brain regions and disrupt neural pathways. Using animal models, it has been demonstrated that induced stress—such as by way of “chronic immobilization”— can cause neural atrophy in the hippocampus (Vyas). Under the same stressful conditions, pyramidal neurons in the basolateral amygdala complex “exhibited enhanced dendritic arborization”— meaning, under pressure, these amygdalar cells actually grew more dendritic connections, with an exception— “Chronic unpredictable stress” had a neutral effect, rather than growth-promoting, on these basolateral pyramidal neurons, whereas the same destructive threat-effects occurred elsewhere in the brain, whether the stressors were predictable or not.

AREA 32. A cingulum is a structure in the form of a belt, or girdle. Cingulate cortex refers to the cortical regions immediately above the corpus callosum bridge connecting the two cerebral hemispheres. Anterior cingulate cortex (ACC), wrapping around much of the callosum, extends forward up to the frontal lobe, forming part of the medial (toward the middle/interior) cerebral hemispheres. Posterior cingulate cortex, wrapping most of the remaining callosum bridge, is situated behind the ACC.

Cingulate cortex is involved in motivation and, relatedly, the selection of what things need to be attended to in the moment. Anterior cingulate cortex has “robust excitatory connections” with the dorsolateral prefrontal cortices (DLPFC) (Medalla, 2012). Though both are active while awake—especially when in deep thought—during REM sleep the cingulate cortex is activated, but the DLPFC is suppressed.

Brodmann Area 32—the dorsal anterior cingulate—wraps around the anterior cingulate gyrus, forming what resembles a dorsal fin at the uppermost, or rostral, surface of the cingulate cortex. During REM sleep, Brodmann Area 9—the DLPFC—receives “inhibitory cholinergic influence” from Area 32. In REM sleep, cholinergic dominance may support some kind of memory consolidation, or other functions, while the synergism between areas 9 and 32, whilst awake—when both are active—appears to support a more reasoned and rationed style of cognition. Depending on whether Area 32 and the DLPFC are working in alliance, or, as in REM sleep, Area 32 is suppressing that most executive of regions, will determine which world you find yourself to be in.

SELECTION VIA INHIBITION. The basal ganglia (BG), inferior to the cortex, is subdivided into the globus pallidus, caudate nucleus, nucleus accumbens, and putamen. The BG is important for the fine-control of voluntary movement, and is also involved in procedural learning, commonly called “motor-memory.” There are areas in the BG which produce, and have receptors for, opioids, and there are profuse cannabinoid receptors in BG zip-codes as well. However, the BG nuclei run primarily on Dopamine (Lazarus, 2012). Parkinson’s and Huntington’s disease, and addiction, involve under-production of Dopamine in the BG, and behavior control disorders—including Tourette’s syndrome and obsessive- compulsive disorder—also involve atypical BG function.

By the mid-1980s, five different circuits connecting the basal ganglia to thalamocortical areas had been identified, including an “oculomotor” circuit, involved in deciding what to look at, and a dorsolateral prefrontal circuit which appeared to be involved in spatial memory (Alexander, 1986). Outputs from the pallidum project to primary motor and premotor cortex, though most of the basal ganglia—while receiving inputs from all over the brain—only sends signals out to other BG regions, suggesting feedback loops, monitoring how motor plans are panning out. It appears that the structures forming the BG work to inhibit motor patterns vying for muscular activation...all except for one of these competing actions— the one that gets through. Imagine a dozen raging horses waiting to be let loose, and instead of a stampede, you choose...one. The gate opens for you, on that stallion, and ya’ll alone. You can only ride in onto the field on one saddle at a time. Those others will be there, waiting, when you need them.

HIPPOCAMPUS, I DECLARE. Recording electrical signals from regions below the cerebral cortex is normally impractical, with an intact skull, but brain- operations open up this possibility. During pre-surgical evaluations it was found that, compared with waking, coherence between the hippocampus and the rhinal cortical areas were decreased by more than half while the patient was sleeping (Fell, 2003). Awake, rhinal-hippocampal communication is partially responsible for the ability to access declarative memories—“explicit memories”—and the rhinal cortex appears to filter familiar events from reaching the hippocampus, so that the hippocampus may focus on more novel occurrences.

It is said that the word hippocampus means “seahorse,” coming from two ancient Greek roots, one meaning “horse,” and the other, “sea monster.” Underneath the temporal lobe is the hippocampal formation— the hippocampus, the dentate gyrus, the parahippocampal gyrus, and the entorhinal cortex. The hippocampus and dentate gyrus, unlike most cortical regions—which contain six neuronal layers—are composed of three or four cell-layers. The hippocampus is central to some forms of learning, and has plenty to do with navigating through space, and with comparing cognitive maps, and with story-telling. We’ll get back on the sea-monster-horse, later.

THE INNER CHAMBER. The thalamus and hypothalamus, together, form the diencephalon. Thalamus is Greek, for “inner chamber.” The thalamus is atop the brainstem and has been called “the gateway to the cortex,” because all sensory output, except for olfactory, innervate and are processed within its various subregions, prior to continuing on to the appropriate primary, and secondary cortical areas. After visual sensations are processed within the retina by multiple cell layers, those data travel along the optic nerve to the lateral geniculate nucleus of the thalamus, and—completing the primary visual pathway—head from there to V1 (Gazzaniga, p77). Signals from the cochlea in the inner ear are relayed via the medial geniculate in the thalamus to the primary auditory cortex. And, as already mentioned, primary somatosensory cortex receives input from the thalamus, relaying skin sensations and data regarding body-part positioning. The thalamus receives inputs from neocortical regions, and the cerebellum and basal ganglia and thalamus all loop signals back to these regions, as well. The thalamus is not only a relay— its pulvinar nucleus integrates information from various cortical regions, baiting some to assume that Consciousness must be “in” the thalamus (p82). Except, olfaction can be conscious without thalamic intervention, suggesting that conscious awareness does not—necessarily—involve chamber- vention.

THALAMIC-NEOCORTICAL N-REM. After 44-hours of sleep deprivation—intended to instigate an initial slow-wave-sleep rebound—EEG and fMRI data were recorded two-and-a-half-minutes into participants’ finally-

realized sleep. Areas including the medial frontal gyrus and posterior cingulate (B- 32) displayed decreased connectivity with the thalamus, “whereas there was a complete absence of neocortical regions displaying increased thalamic connectivity” (Picchioni, 2014). In stage 2 sleep, “more clusters of significant decreases were observed,” although the stage 2 thalamic deafferentation to cortical regions was similar as in stage 1. It was conjectured that reduced thalamic transmission acts to gate the sleeping mind from environmental intrusions.

Underneath the thalamus is the hypothalamus, a master control-center for many parasympathetic functions. The hypothalamus is involved in emotional processing and is connected to—and in large-part in control of—the pituitary gland and is thus charged with maintaining some semblance of homeostasis in the body. During REM sleep, temperature regulation may be suspended— under jurisdiction of the hypothalamus (Libert, 2003). The hypothalami, particularly their preoptic area, have the greatest increase in “metabolic activity within the dopaminergic systems” whilst dreaming, making these modules key players “in the neurostructural model of dreaming” (Yu, 2011). The hypothalami are “centrally involved in male sexuality,” as well, and their being excited during REM sleep is probably why your nethers regions are, also (Yu, 2016).

CEREBELLUM. Although it translates to "small brain," the cerebellum actually has as many neurons as the rest of the entire nervous system— it's just more compact. Located below the cerebral hemispheres, and toward the rear of the head, the cerebellum is connected to the rest of the brain via the pons and medulla, making it, essentially, a feedback-extension for channels traversing through the brainstem.

Input to the cerebellum may terminate at one of four nuclei clusters, deep within the structure, but most enervation ends at synaptic connections on the cerebellar cortex, its rind. Information makes it to the cerebellum from both motor and sensory cortical areas, and these data are processed in the cerebellum— apparently—to better recognize and facilitate body positioning. Not only do balance signals arrive in the cerebellum from vestibular projections, but there are also visual and auditory connections sent to the cerebellar mini-brain, all to inform you of a better integrated perception of the body-in-space. All output signals from the cerebellum stem from those deep nuclei, some arriving at the thalamus above, and from there, onto motor and premotor areas, while other pathways project to brainstem nuclei below, affecting output to the spinal cord.

BRAIN STEM. The “Hind Brain”— a 555-million-year patina, and still tickin’. The brain stem consists of the metencephalon and the myelencephalon, or, the pons and the medulla, respectively. The bottom-most region of the brain is called the medulla, and, continuous with the spinal cord, its primary role is to act as a conduit relaying sensory information up to higher regions. Signals arrive at

nuclei within the medulla before being sent along to the thalamus, and from there, on to somatosensory cortex. Neck, throat, face, and tongue muscles, and the heart, also receive input from the medulla. Above the medulla is the pons.

The pons is filled with its pontine nuclei and receives projections from vestibular and auditory cortical regions above, and also from both sensory and motor regions for the face and mouth. The pons is where most of what is called the reticular formation is located, and I suspect—along with the late Jouvet—it may be the depot or bridge to a collection of ancient “behavioral scripts.” In the 1940s researchers discovered that if you stimulated the reticular formation this would awaken sleeping cats and, if it was damaged, “resulted in a state of permanent coma” (LaBerge, 1985, p46). This was among the first evidences of hypnogogic— sleep-inducing—mechanisms originating in specific brain modules.

In 1959, Francois Michel and Michel Jouvet gave us “paradoxical sleep” (PS), referring to a third major brain state to accompany waking and slow wave sleep. This PS coincided with the REM epochs described by Kleitman and company a few years earlier, and the “Michels” highlighted the fact that, from a master control network in the brainstem, during PS cortical activity re-achieves waking-like activation levels—even in motor areas—and simultaneously the skeletal muscular system is actively inhibited from carrying-out these behaviors...hence the term “paradoxical.”

Coinciding with REM sleep, the pons, the lateral geniculate nucleus, and the occipital cortex send ponto-geniculo-occipital bursts—or, PGO waves—to the basal ganglia, which then sends beta waves to the anterior cingulate cortex (ACC) and to the dorsolateral-prefrontal cortex, which are also communicating with each other. Simultaneously, the hippocampus sends theta waves to the ACC. Species- specific PGO patterns have been recorded in animals, and a sort of wave pattern fingerprint has also been found in homozygous (“identical”) twins, measured across several nights (Chouvet, 1983). Heterozygous twins exhibited “totally different” PGO patterns (Jouvet, 1998).

Jouvet proposed that the PGO system may be “an endogenous genetic programming system.” The combination of PGO activity and activation of the hippocampus, together with “fast cortical activity,” might be a sufficient trifecta for forming vivid dreams in the sleeping mind. Jouvet would lesion the motor- inhibiting pathways in cats so their muscular systems were free to move during PS, disclosing their “oneiric behaviour” (e.g., chasing phantom mice around)— integrating, assumedly, both bottom-up genetic influences and also top-down modulation from the cerebral cortex…