Brain: Internal and External Worlds

The Internal and External Worlds of Our Brain

The brain is an organ, but it is not an isolated organ. It is connected in various ways with the other organs of the body. This vital fact about the brain and how it works is all too often overlooked, especially by people who like to think of the brain as something analogous to a computer.

In a nutshell, the brain is connected to two “worlds”: the world within us, the internal milieu of the body; and the world outside us, the external environment. In a profound sense, the principal task of the brain is to mediate this divide – to mediate between the vital requirements of the internal milieu of the body (the vegetative functions) and the ever-changing world around us, which is the source of everything our bodies need but is indifferent to those needs (with the exception of our parents – especially during childhood – and other loved ones, who for that very reason occupy a special place in the mental economy).

The vegetative nervous system performs the task of keeping the body alive from moment to moment, controlling heart rate, breathing, digestion, temperature, and so forth. To perform these functions, the body requires, and actually consumes, material from the outside world – principally food, water, and oxygen. It also requires a suitable ambient temperature, as the organs of the body can only function within a very narrow temperature range. The same applies to sexual needs – though sexual “consummation” is necessary for the survival of our species as a whole rather than of each one of us individually. In short, to maintain and sustain the visceral jellyfish that we all have inside us, the internal world of the body has to interact in an appropriate way with the external world around us and make the world meet its needs, and it is the brain that manages this difficult task. When the external world no longer meets our many needs (when the brain is no longer able to regulate the inner functions of our bodies, by virtue of its interactions with the external world), we die – of hunger, thirst, suffocation, heatstroke, or one of the many other hazards that constantly threaten the integrity of the internal world of the body.

This point is obvious, and clearly irrevocable. How, then, does the brain perform these vital functions? In a broad sense, to begin with, we can address a narrower question: How is the brain linked, anatomically and physiologically, with the inner and outer world of the body?

It is important to remember that the action system always operates in concert with the perceptual systems, the primary function of which is to guide action. Photo by Elena.

Perceiving and representing the external world

The brain is connected to the outside world in two main ways. The first is through the sensory apparatus (the organs of vision, hearing, etc.); the second is through the motor apparatus (the so-called musculoskeletal system). This is how we receive information from the world and how we act on the world.

The essential facts are that sensation is generated by specialized sensory receptors (in the eye, ear, etc.), that transform selected physical features of the environment into nerve impulses and send the resultant information to the brain. In the case of vision, cells in the retina send (most, but not all) visual information, via part of the thalamus, to the back of the occipital lobes. A similar arrangement applies to hearing, in which case (most, but not all) auditory information is transmitted (via a different part of the thalamus) to the superior surface of the temporal lobe. In the case of somatic sensation (touch, pain, etc.), the relevant information is sent from the surfaces and joints of the body to (mainly) the anterior part of the parietal lobe. Many people refer to somatic sensation as the sense of “touch”. In fact, touch is part of a group of different sensory modalities that transmit several types of information from the surfaces of the body, of which tactile sensation is only one. There is also vibration sense, temperature sense, pain sense, and muscle- and joint-position sense. Each of these could be regarded as a sense modality in its own right, in that each is served by a specific type of receptor and projects separately to the brain. However, all these sense modalities send information to a roughly similar location in the brain, in the parietal lobe, which forms the basis of the body schema, and they are therefore grouped together as “somatic sensation”.

It is important to be aware that the modality of somatic sensation carries only part of the information about the state of the body to the brain – that is, information about the external aspect of the body., the “musculoskeletal” part, which is in contact with the outer world. We need to know about pain and temperature in the outside world in order to act on it. Information about the internal world, relating to the viscera, is not conveyed by sensors such as those for touch, pain, and do forth.

The two remaining sensory modalities – taste and smell – are “chemical” in nature. Taste is closely connected to somatic sensation in the tongue and is represented mainly in the cortex of the insula. Smell is connected to a range of structures inside the temporal lobe, including some parts of the limbic system.

The internal world

Until very recently, there was far less investigation of neuropsychological matters pertaining to the second aspect of reality – the influence of the inner world of the body on our mental life.

The internal milieu refers to the world of respiration, digestion, blood pressure, temperature control, sexual reproduction, and the like. These organs are responsible for the body's survival and in most cases loss of their functions would mean a rapid end to the life of the organism.

Information travels up through the spinal cord (and in other ways) from the interior of the body. This information reaches, in the first instance, the hypothalamus – which is the controlling mechanism (or “head ganglion”) of the autonomic nervous system (the system that controls the self-regulation aspects of the body). The hypothalamus is intimately connected with the group of structures known as the limbic system. One could say (using the language employed above in relation to external perceptions and action) that the functions of the internal milieu are “projected” onto the hypothalamus. The hypothalamus relays this information to a range of other structures throughout the limbic system and rest of the brain. In this way, the prevailing state of the body is linked with concurrent objects in the external world, and these links (which are of crucial importance for survival) are committed to memory.

Alongside the “perceptual” aspect of this internally directed system, there is also a “motor” component. There are two classes of action performed by this system. One influences the visceral milieu itself (via secretory discharges, vasomotor changes, etc.) These influences are mediated by the autonomic nervous system. But the visceral brain influences external action too. External action is mediated by the motor systems already discussed above, but, unlike voluntary action, the visceral brain releases stereotyped motor patterns, executed under compulsive pressure. This is the basis of instinctual behaviors and the expression of the emotions. Unlike voluntary action, this type of motor activity is mediated primarily by the basal ganglia. However, information about the state of the internal milieu also reaches the prefrontal lobes – where it makes an important contribution to the calculations performed by the unit for the programming, regulation, and verification of action.

Over most of the last century, neuroscience studied interaction of the mind with the environment, and tremendous progress was made. Picture by Elena.

The Brain and the Inner World, Introduction to Basic Concepts. Mark Solms, Oliver Turnbull.

Physiological Principles

Physiological Principles that distinguish the outer and inner worlds of our brain

The outer and inner sources of information can be distinguished not only on anatomical grounds, but on physiological grounds as well. The basic physiological division is embodied in the distinction that some neuroscientists draw between “channel” and “state” functions – the terms introduced by Mesulam  in 1998. His terminology is fairly idiosyncratic, but it denotes a relatively conservative concept, the physiological foundations of which are widely accepted. Other neuroscientists distinguish between the “contents” and “level” of consciousness – but these terms are less serviceable as they refer specifically to consciousness and thereby exclude the possibility of unconscious mental  processes. Mesulam's distinction between the channel and state functions of the brain is perhaps roughly equivalent to the distinction that psychoanalysis draw between mental representations (“traditional traces”) and mental energies (“quotas of affect”).

Brain functions (principally, forebrain functions) dependant on information derived from the external world are primarily channel-dependent functions. This means that the information processed by these systems comes in discrete bits and is communicated via distinct and specific pathways. Information transmitted from a particular source within a channel-dependent system is not widely distributed to the brain as a whole but, rather, is targeted with great accuracy to other discrete regions. For example, when information arrives at a particular location on the retinae (say 30 degrees below the horizontal and 20 degrees left of the vertical meridian), it projects to a highly specific area of primary visual cortex which represents that precise location on the retinae (and therefore in the external visual field). The coral aspects of this information then project to specific color areas, as do the motion aspects, and so on. In each case, a limited number of neurons directly “speak to” a limited number of other neurons some distance away, while the vast bulk of the brain is completely unaffected by the interaction. Thus Region A connects to Region B, which connects to Region C. Regions L, M, and N, which also connect with each other, are never involved in the interaction between Regions A, B, and C. Ring-fenced interaction of this kind occurs not only in the visual system, but in more or less all the externally directed functional systems of the brain.

This type of interaction between neurons involves three main neurotransmitters. The principal excitatory neurotransmitters are glutamate and aspartate. The principal inhibitory neurotransmitter is GABA (gamma-aminobutyric acid). These are the most common neurotransmitters in the brain, and they dominate the activity of all channel functions.

The internally directed brain structures, units for modulating cortical tone and arousal, operate in an entirely different way. Here, the means of communication is more gross and involves widespread and global effects that reflect changes in the state of the organism rather than in specific information-processing channels. The neurons of single brain-stem nuclei in the state-dependent systems project onto extremely large numbers of other neurons in the source nuclei.

The forebrain neurons thus affected are extremely widely distributed within the brain, so that a nucleus in the brainstem can influence neurons in all lobes of the forebrain simultaneously. In addition, forebrain neurons affected by one state-dependent nucleus can simultaneously be influenced by another one; in these systems there are no specific pathways (channels) but, rather, a number of overlapping “fields of influence”.  The specific serial linkages between regions in the channel systems are replaced by overlapping and interacting fields. Even more characteristic of the state-dependent systems is the fact that they are also open to influence by chemicals other than neurotransmitters, which link the brain directly with the visceral body.

Brain's distinctions is similar to the distinction that Freud drew between mental “quality” and mental “quantity”. Illustration by Elena.

The Brain and the Inner World, Introduction to Basic Concepts. Mark Solms, Oliver Turnbull.

Cosmic Drama

The Fate of the Solar System

A supernova can be brighter than the combined radiance of all the other stars in the galaxy within which it is embedded.

Planets near stars much more massive than the Sun will be melted and frizzled by their sun when it becomes an erupting supernova, since these massive stars with higher temperatures and pressure run rapidly through their store of nuclear fuel, and their lifetimes are thus much shorter than the Sun’s.  In fact, a star tens of times more massive than the Sun can stably convert hydrogen to helium for only a short period of time – less than few millions years before moving on to more exotic nuclear reactions. All those massive blue-white supergiant stars in Orion are destined in the next few million years to become supernovae.

The essential preliminary to a supernova explosion is the generation of a massive iron core. Under enormous pressure, the free electrons in the stellar interior are melted with protons of the iron nuclei, the equal and opposite electrical charges canceling each other out;  the inside of the star is turned into a giant atomic nucleus, occupying a much smaller volume than the precursor electrons and iron nuclei.

A silicon fusion occurs and the core implodes violently, the exterior rebounds and a supernova explosion results.

On massive stars thus there is not enough time for the evolution of advanced forms of life on any accompanying planets. There will be not any beings there that could see their star become a supernova. Indeed, if intelligent beings live long enough to understand supernovae, their star is unlikely to become one.

The awesome supernovae explosion ejects into space most of the matter of the precursor star - residual hydrogen, helium, carbon, silicon, iron, uranium… Remaining is a core of hot neutrons, bound together by nuclear forces. This core is a single atomic nucleus with very heavy atomic weight. It becomes a neutron star thirty kilometers across: a rapidly rotating, tiny, shrunken, dense, withered stellar fragment. As the core of a massive red giant star collapses to form such a neutron star, it spins faster. The neutron star at the center of the Crab Nebula is an immense atomic nucleus, about the size of Manhattan, spinning thirty times a second. Its powerful magnetic field, amplified during the collapse, traps charges particles rather as the much tinier magnetic field emit beamed radiation not only at radio frequencies but in visible light as well. However, the fate of the inner solar system as the Sun becomes a red giant is grim enough.

Many stars in the Orion Constellation will become supernovae - a continuing cosmic fireworks in the constellation of the hunter. Image: © Megan Jorgensen.

OCD Patients

Obsessive-Compulsive Disorder Patients

Soon after obsessive worries begin, OCD patients typically do something to diminish the worry, a compulsive act. If they feel they have been contaminated by germs, they wash themselves; when that doesn't make the worry go away, they wash all their clothing, the floors, and then the walls. If a woman fears she will kill her baby, she wraps the butcher knife in cloth, packs it in a box, locks it in the basement, then locks the door to the basement. The UCLA psychiatrist Jeffrey M. Schwartz describes a man who feared being contaminated by the battery acid spilled in car accidents. Each night he lay in bed listening for sirens that would signal an accident nearby. When he heard them, he would get up, no matter what the hour, put on special running shoes, and drive until he found the site. After the police left, he would scrub the asphalt with a brush for hours, then skulk home and throw out the shoes he had worn.

Obsessive doubters often develop “checking compulsions.” If they doubt they've turned off the stove or locked the door, they go back to check and recheck often a hundred or more times. Because the doubt never goes away, it might take them hours to leave the house.

People who fear that a thud they heard while driving might mean they ran someone over will drive around the block just to make sure there is no corpse in the road. If their obsessional fear is of a dread disease, they will scan and rescan their body for symptoms or make dozens of visits to the doctor. After a while these checking compulsions are ritualized. If they feel they have been dirtied, they must clean themselves in a precise order, putting on gloves to turn on the tap and scrubbing their bodies in a particular sequences ; if they have blasphemous or sexual thoughts, they may invent a ritual was of praying a certain number of times. These rituals are probably related to the magical and superstitious beliefs most obsessionals have. If they have managed to avoid disaster, it is only because they checked themselves in a certain way, and their only hope is to keep checking in the same way each time.

Obsessive-compulsives, so often filled with doubt, may become terrified of making a mistake and start compulsively correcting themselves and others. One woman took hundreds of hours to write brief letters because she felt so unable to find words that didn't feel “mistaken”. Many a Ph.D. Dissertation stalls – not because the author is a perfectionist, but because the doubting writer with OCD can't find words that don't “feel” totally wrong.

When a person tries to resist a compulsion, his tension mounts to a fever pitch. If he acts on it, he gets temporary relief, but this makes it more likely that the obsessive thought and compulsive urge will only be worse when it strikes again.

OCD is very difficult to treat. Medication and behavior therapy are only partially helpful for many people. 

Even some forms of obsessive jealousy, substance abuse, compulsive sexual behaviors, and excessive concern about what others think about us, self-image, the body, and self-esteem can be helped.

(Brain Lock Unlocked. The Brain That Changes Itself by Norman Doidge, M.D., excerpt).

Monkey Wrench Gang

The Monkey Wrench Gang

(excerpt)

By Edward Abbey

He turned back on the highway and followed it for another ten miles, driving without lights. Dangerous? Perhaps. But not impossible. Hayduke had not noo much difficulty staying on the road. Bonnie Abbxug chewed her anxious knuckles and offered plenty of unwanted advice, like ”For God's sake turn the light on. You want to get us both killed?” His only immediate worry was horses: hard enough to see horses at night even with the lights.

They arrived at the dirt road leading northeast to Shonto and Betatakin. Hayduke turned and once well away from the state road switched on the lights. They made good time, stopping only at a lonely spot out in the desert, between two wind-stripped, dead and silvery junipers to recover the goods, packed in heavy canvas duffel bags, which the Gang had cached there after the railway bridge operation. That had been Hayduke's idea – he wanted the dynamite in the bags for what he called “sanitary” reasons and for easier backpacking later. Abbzug had salvaged the empty boxes; that was her idea.

As Hayduke loaded the two bulging bags into the rear she again complained, “I'm not going to ride in the same car with that stuff! But again - “Walk then!” - she was overruled. They trundled on. Getting low on fuel. Hayduke stopped under the seats until he found campground at Betatakin. He groped under the seats until he found his Oklahoma cred card, a length of neoprene tubing – My leetle robber hose, senor, as he called it fondly – and disappeared into the darkness with siphon and two gasoline cans.

Bonnie waited, rehearsing once again all the tedious questions about her own sanity. No question at all about that of her companion, or that polygamous jack-Mormon river guide, or poor mad Doc. But what am I doing here? Me, a nice Jewish girl, with an M.A. In Classican (yeah!) French Lit. With a mother who worries about me and a father who makes 40,000 a year. Forty thousand what” Forty thousand ladies' foundation garments, what else. Me, Abbzug. A solid, sensible  gril with a keppela on her shoulders. Running around with these crazy goyim in the middle of Arabia. We'll never get away with it. They got laws.

Hayduke came back, two full cans pulling his arms down straight. Groping again under the front seats-copping as he did a free feel between Bonnie's thighs – he found his spout and poured ten gallons into the tank. Started to walk away again with the empties.

“Where're you going now?”

“Go to fill the auxiliary tank.”

God! Gone. She waited, cursing herself, wanting to sleep and quite unable, dozing in fits and waking up in terror.

Sound and smell of pouring gasoline. They were off again, into the night, running as Hayduke liked it best, full and cool. With transfigured license plates both fore an aft. “We're from South Dakota tonight,” he explained.

Bonnie groaned.

“Relax,” he said, “we're crossing the river soon. We're getting out of this overdeveloped hypercivilized goddamn Indian country. Going back to the canyons where people like us belong. They won't find un is a million years.”

A little lady. Illustration by Elena.