#28. The Origin of Consciousness [neuroscience]

NE

Red, theory; black, fact.

After perusing Gideon Rosenblatt's blog at the prompting of Google, I finally saw the need for this post.

I theorize that we begin life conscious only of our own emotions. Then the process of classical conditioning, first studied in animals, brings more and more of our environment into the circle of our consciousness, causing the contents of consciousness to become enriched in spatial and temporal detail. Thus, you are now able to be conscious of these words of mine on the screen. However, each stroke of each letter of each word of mine that now reaches your consciousness does so because, subjectively, it is "made of" pure emotion, and that emotion is yours.

Some analogies come to mind. Emotion as the molten tin that the typesetter pours into the mold, the casting process being classical conditioning and the copy the environmental data reported by our sense organs. Emotion as the bulk on one side of a fractal line and sensory data the bulk on the other side. Emotion as an intricately ramifying tree-like structure by which sensory details can send excitation down to the hypothalamus at the root and thus enter consciousness.

The status of "in consciousness" can in principle affect the cerebral cortex via the projections to cortex from the histaminergic tuberomamillary nucleus of the hypothalamus. Histamine is known to have an alerting effect on cortex, but to call it "alerting" may be to grossly undersell its significance. It may carry a consolidation signal  for declarative, episodic, and flash memory. Not for a second do I suppose all of that to be packed into the hippocampus, rather than being located in the only logical place for it: the vast expanse of the human cerebral cortex.

#22. The Cogs of Armageddon [evolutionary psychology]

EP

Red, theory; black, fact.

1-27-2017

This is a "just-so story" about how I believe everyday human behavior eventually accomplishes the all-important biological function of dispersal for the human race. A future post will attempt to explain how the "just-so story" got written in terms of natural selection and possible faster-acting proxies thereof needed by organisms with long generation times.

Dispersal is things like dandelions shedding airborne seeds, slime molds developing into spore cases on stalks and releasing the spores into the wind, territorial systems of birds and mammals forcing the unlanded young to seek widely for their own territories, and humans going into space because our science fiction writers keep scaring us about the possibility of meteor crashes wiping out life on Earth. To paraphrase the latter, a way to avoid extinction, long-term, is not putting all your eggs in one basket, geographically speaking.

The slime mold dictyostelium is triggered into its dispersal program by the food supply running short; I will adopt the assumption that the human dispersal program is also triggered by the end of the good times, that is, the price of bread rising relative to wages.

I conjecture that human neural pathways potentiate aggression when the hard times come, but of an elaborate kind adapted for ensuring efficient dispersal (i.e., with minimal loss of life). It begins with a two-person feud of the sort illustrated in cultural references too numerous to mention. In Canada, where I live, a cough accompanied by an angry expression plays the role of the instigation. The arbitrary stimulus, made offensive by some piece of Pavlovian conditioning, is traded back and forth with rapidly increasing energy. The process is remarkably like flirting, not surprising since the ultimate purpose has commonalities with reproduction--but of an entire society. 

However, the emotional component is strongly threatening rather than rewarding, because the participants must be induced to seek allies, which people do when threatened, until all of society is eventually polarized. The acts of provocation being traded back and forth become progressively more outrageous, as they must, to keep the polarization process going. Eventually, one side gets the upper hand and forces the other to flee.

The result is a diaspora, i.e., dispersal. Because of the long polarization process, an entire group is expelled, not single individuals one at a time. Thus, members of such a group can assist each other to survive and relocate, thereby reducing the mortality associated with dispersal, thereby making the dispersal event more efficient in terms of number of people relocated. The group who flees is then seen by the international community as the blameless victim, and the group who stays is seen as the unprincipled aggressor. This tends to elicit a sheltering of the refugees and an intimidation of the "aggressor," who is deterred from pressing his advantage, that is, pursuing the refugees and slaughtering them to the last man, which is what each side would dearly like to do to the other by this point. This, again, is an efficiency from the point of view of producing dispersal.

However, if each side is continually threatening the other, why don't they flee each other's presence during the very early stages? The answer seems to be that humans have a reflex that converts feeling threatened into a wish to injure the threatening party, possibly a behavioral leftover from some earlier adaptation, such as an anti-predation defense; to injure, you have to stick around. (Leftovers such as these form the building blocks of future just-so plots.)

Finally, settled refugees usually do not integrate completely into the host society, instead forming ethnic neighborhoods. This increases the resemblance to an entire society reproducing itself. However, the growth phase following reproduction in individuals seems to be lacking at the society level. However, being seen as ethnic by the host society, due to slow integration, could improve individual-level reproductive success of refugees because of disassortative mate-choice effects evolved to favor genes that produce dispersal.

2-24-2017

The dispersal-producing dynamic just outlined is fantastically powerful, as it must be to overcome all the reasons you would not leave your homeland forever at some arbitrary time: expense, risk of mortality in transit, opportunity costs, temporary loss of livelihood, need to learn a new language and customs, vulnerability to exploitation in the new country, etc., etc.

This dynamic is basically what theologians call evil, for which I propose the less judgmental, substitute term "dispersalism." If this is truly an insight, it should have a liberating effect on your life, even if you just remember that one word, but with the price of always being population-conscious: always trying to see what is happening at the population/zeitgeist level, and reading the paper every day at the very least.

At least one "just-so story" could probably be written for each of the pillars of the human species-specific objective function mentioned in previous posts, these being as follows: dispersal, genetic diversity, memetic diversity, and altruism. (The latter has not been mentioned until now.) Each of these must be optimized, not blindly maximized, for each comes at a cost. In terms of neurobiology, each pillar is probably a family of functionally related likes and dislikes wired up in the hypothalamus, but not obviously related to individual-level survival or reproduction.

#16. The Intermind, Engine of History? [evolutionary psychology]

EP

Red, theory; black, fact.

9-21-2016

This post is a further development of the ideas in the post, "What is intelligence? DNA as knowledge base." It was originally published 9-21-2016 and extensively edited 10-09-2016 with references added 10-11-2016 and 10-30-2016. Last modified: 10-30-2016.

In "AviApics 101" and "The Insurance of the Heart," I seem to be venturing into human sociobiology, which one early critic called "An outbreak of neatness." With the momentum left over from "Insurance," I felt up for a complete human sociobiological theory, to be created from the two posts mentioned.

However, what I wrote about the "genetic intelligence" suggests that this intelligence constructs our sociobiology in an ad hoc fashion, by rearranging a knowledge base, or construction kit, of "rules of conduct" into algorithm-like assemblages. This rearrangement is (See Deprecated, Part 7) blindingly fast by the standards of classical Darwinian evolution, which only provides the construction kit itself, and presumably some further, special rules equivalent to a definition of an objective function to be optimized. The ordinary rules translate experiences into the priming of certain emotions, not the emotions themselves, 

Thus, my two sociobiological posts are best read as case studies of the products of the genetic intelligence. I have named this part the intermind, because it is intermediate in speed between classical evolution and learning by operant conditioning. (All three depend on trial-and error.) The name is also appropriate in that the intermind is a distributed intelligence, acting over continental, or a least national, areas. If we want neatness, we must focus on its objective function, which is simply whatever produces survival. It will be explicitly encoded into the genes specifying the intermind, (For more on multi-tier, biological control systems with division of labor according to time scale, see "Sociobiology: the New Synthesis," E. O. Wilson, 1975 & 2000, chapter 7.)

Let us assume that the intermind accounts for evil, and that this is because it is only concerned with survival of the entire species and not with the welfare of individuals. Therefore, it will have been created by group selection of species. (Higher taxonomic units such as genus or family will scarcely evolve because the units that must die out to permit this are unlikely to do so, because they comprise relatively great genetic and geographical diversity.* However, we can expect adaptations that facilitate speciation. Imprinted genes may be one such adaptation, which might enforce species barriers by a lock-and-key mechanism that kills the embryo if any imprinted gene is present in either two or zero active copies.) Species group selection need act only on the objective function used by epigenetic trial-and-error processes.

In these Oncelerian times, we know very well that species survival is imperiled by loss of range and by loss of genetic diversity. Thus, the objective function will tend to produce range expansion and optimization of genetic diversity. My post "The Insurance of the Heart" concluded with a discussion of "preventative evolution," which was all about increasing genetic diversity. My post "AviApics 101" was all about placing population density under a rigid, negative feedback control, which would force excess population to migrate to less-populated areas, thereby expanding range. Here we see how my case studies support the existence of an intermind with an objective  function as described above.

However, all this is insufficient to explain the tremendous cultural creativity of humans, starting at the end of the last ice age with cave paintings, followed shortly thereafter by the momentous invention of agriculture. The hardships of the ice age must have selected genes for a third, novel component, or pillar, of the species objective function, namely optimization of memetic diversity. Controlled diversification of the species memeplex may have been the starting point for cultural creativity and the invention of all kinds of aids to survival. Art forms may represent the sensor of a feedback servomechanism by which a society measures its own memeplex diversity, measurement being necessary to control.

A plausible reason for evolving an intermind is that it permits larger body size, which leads to more internal degrees of freedom and therefore access to previously impossible adaptations. For example, eukaryotes can phagocytose their food; prokaryotes cannot. However, larger body size comes at the expense of longer generation time, which reduces evolvability. A band of high frequencies in the spectrum of environmental fluctuations therefore develops where the large organism has relinquished evolvability, opening it to being out competed by its smaller rivals. 

The intermind is a proxy for classical evolution that fills the gap, but it needs an objective function to provide it with its ultimate gold standard of goodness of adaptations. Species-replacement group selection makes sure the objective function is close to optimal. This group selection process takes place at enormously lower frequencies than those the intermind is adapting to, because if the timescales were  too similar, chaos would result. For example, in model predictive control, the model is updated on a much longer cycle than are the predictions derived from it.

12-25-2016

Today, when I was checking to see if I was using the word "cathexis" correctly (I wasn't), I discovered the Freudian term "collective unconscious," which sounds close to my "intermind" concept.

* 3-12-2018

I now question this argument. Why can't there be as many kinds of group selection as taxonomic levels? Admittedly, the higher-level processes would be mind-boggling in their slowness, but in evolution, there are no deadlines.

#10. The Two–test-tube Experiment: Part II [neuroscience]

NE

Red, theory; black, fact.

At this point we have a problem. The experimenting-brain theory predicts zero hard-wired asymmetries between the hemispheres. However, the accepted theory of hemispheric dominance postulates that this arrangement allows us to do two things at once, one task with the left hemisphere and the other task with the right. The accepted theory is basically a parsimony argument. However, this argument predicts huge differences between the hemispheres, not the subtle ones actually found.

My solution is that hard-wired hemispheric dominance must be seen as an imperfection of symmetry in the framework of the experimenting brain caused by the human brain being still in the process of evolving, combined with the hypothesis that brain-expanding mutations individually produce small and asymmetric expansions. (See Post 45.) Our left-hemispheric speech apparatus is the most asymmetric part of our brain and these ideas predict that we are due for another mutation that will expand the right side, thereby matching up the two sides, resulting in an improvement in the efficiency of operant conditioning of speech behavior.

These ideas also explain why speech defects such as lisping and stuttering are so common and slow to resolve, even in children, who are supposed to be geniuses at speech acquisition.

This is how the brain would have to work if fragments of skilled behaviors are randomly stored in memory on the left or right side, reflecting the possibility that the two hemispheres play experiment versus control, respectively, during learning.

The illustration shows the theory of motor control I was driven to by the implications of the theory of the dichotomously experimenting brain already outlined. It shows how hemispheric dominance can be reversed independently of the side of the body that should perform the movement specified by the applicable rule of conduct in the controlling hemisphere. The triangular device is a summer that converges the motor outputs of both hemispheres into a common output stream that is subsequently gated into the appropriate side of the body. This arrangement cannot create contention because at any given time, only one hemisphere is active. Anatomically, and from stroke studies, it certainly appears that the outputs of the hemispheres must be crossed, with the left hemisphere only controlling the right body and vice-versa.

However, my theory predicts that in healthy individuals, either hemisphere can control either side of the body, and the laterality of control can switch freely and rapidly during skilled performance so as to always use the best rule of conduct at any given time, regardless of the hemisphere in which it was originally created during REM sleep.

The first bit is calculated and stored in the basal ganglia. It would be output from the reticular substantia nigra (SNr) and gate sensory input to thalamus to favor one hemisphere or the other, by means of actions at the reticular thalamus and intermediate grey of the superior colliculus. The second bit would be stored in the cerebellar hemispheres and gate motor output to one side of the body or the other, at the red nucleus. Conceivably, the two parts of the red nucleus, the parvocellular and the magnocellular, correspond to the adder and switch, respectively, that are shown in the illustration.

Under these assumptions, the corpus callosum is needed only to distribute priming signals from the motor/premotor cortices to activate the rule that will be next to fire, without regard for which side that rule happens to be on. The callosum would never be required to carry signals forward from sensory to motor areas. I see that as the time-critical step, and it would never depend on getting signals through the corpus callosum, which is considered to be a signaling bottleneck.

How would the basal ganglia identify the "best" rule of conduct in a given context? I see the dopaminergic compact substantia nigra (SNc) as the most likely place for a hemisphere-specific "goodness" value to be calculated after each rule firing, using hypothalamic servo-error signals processed through the habenula as the main input for this. The half of the SNc located in the inactive hemisphere would be shut down by inhibitory GABAergic inputs from the adjacent SNr. The dopaminergic nigrostriatal projection would permanently potentiate simultaneously-active corticostriatal inputs (carrying context information) to medium spiny neurons (MSNs) of enkephalin type via a crossed projection, and to MSNs of substance-P type via uncrossed projections. The former MSN type innervates the external globus pallius (GPe), and the latter type innervates the SNr. These latter two nuclei are inhibitory and innervate each other. 

I conjecture that this arrangement sets up a winner-take-all kind of competition between GPe and SNr, with choice of the winner being exquisitely sensitive to small historical differences in dopaminergic tone between hemispheres. The "winner" is the side of the SNr that shuts down sensory input to the hemisphere on that side. The mutually inhibitory arrangement could also plausibly implement hysteresis, which means that once one hemisphere is shut down, it stays shut down without the need for an ongoing signal from the striatum to keep it shut down.

Each time the cerebral cortex outputs a motor command, a copy goes to the subthalamic nucleus (STN) and could plausibly serve as the timing signal for a "refresh" of the hemispheric dominance decision based on the latest context information from cortex. The STN signal presumably removes the hysteresis mentioned above, very temporarily, then lets the system settle down again into possibly a new state.

We now need a system that decides that something is wrong, and that the time to experiment has arrived. This could plausibly be the role of the large, cholinergic inter neurons of the striatum. They have a diverse array of inputs that could potentially signal trouble with the status quo, and could implement a decision to experiment simply by reversing the hemispheric dominance prevailing at the time. Presumably, they would do this by a cholinergic action on the surrounding MSNs of both types.

Finally, there is the second main output of the basal ganglia to consider, the inner pallidal segment (GPi). This structure is well developed in primates such as humans but is rudimentary in rodents and even in the cat, a carnivore. It sends its output forward, to motor thalamus. I conjecture that its role is to organize the brain's knowledge base to resemble block-structured programs. All the instructions in a block would be simultaneously primed by this projection. The block identifier may be some hash of the corticostriatal context information. A small group of cells just outside the striatum called the claustrum seems to have the connections necessary for preparing this hash. Jump rules, that is, rules of conduct for jumping between blocks, would not output motor commands, but block identifiers, which would be maintained online by hysteresis effects in the basal ganglia.

The cortical representation of jump rules would likely be located in medial areas, such as Brodmann 23, 24, 31, and 32. BA23-24 is classed as limbic system, and BA31-32 is situated between this and neocortex. This arrangement suggests that, seen as a computer, the brain is capable of executing programs with three levels of indentation, not counting whatever levels may be encoded as chromatin marks in the serotonergic neurons. Dynamic changes in hemispheric dominance might have to occur independently in neocortex, medial cortex, and limbic system.

#5. Why We Dream [neuroscience]

NE
Red, theory; black, fact.

The Melancholy Fields

Something I still remember from Psych 101 is the prof's statement that "operant conditioning" is the basis of all voluntary behavior. The process was discovered in lab animals such as pigeons by B.F. Skinner in the 1950s and can briefly be stated as "If the ends are achieved, the means will be repeated." (Gandhi said something similar about revolutionary governments.)

I Dream of the Gruffalo. Pareidolia as dream imagery.

Let's say The Organism is in a supermarket checkout line and can't get the opposite sides of a plastic grocery bag unstuck from each other no matter how it rubs, blows, stretches, picks at, or pinches the bag. At great length, a rubbing behavior by chance happens near the sweet spot next to the handle, and the bag opens at once. Thereafter, when in the same situation, The Organism goes straight to the sweet spot and rubs, for a great savings in time and aggravation. This is operant conditioning, which is just trial-and-error, like evolution itself, only faster. Notice how it must begin: with trying moves randomly--behavioral mutations. However, the process is not really random like a DNA mutation. The Organism never tries kicking out his foot, for example, when it is the hand that is holding the bag. Clearly, common sense plays a role in getting the bag open, but any STEM-educated person will want to know just what this "common sense" is and how you would program it. Ideally, you want the  creativity and genius of pure randomness, AND the assurance of not doing anything crazy or even lethal just because some random-move generator suggested it. You vet those suggestions.

That, in a nutshell, is dreaming: vetting random moves against our accumulated better judgment to see if they are safe--stocking the brain with pre-vetted random moves for use the next day when stuck. This is why the emotions associated with dreaming are more often unpleasant than pleasant: there are more ways to go wrong than to go right (This is why my illustrations for this post are melancholy and monster-haunted.) The vetting is best done in advance (e.g., while we sleep) because there's no time in the heat of the action the next day, and trial-and-error with certified-safe "random" moves is already time-consuming without having to do the vetting on the spot as well.

Dreams are loosely associated with brain electrical events called "PGO waves," which begin with a burst of action potentials ("nerve impulses") in a few small brainstem neuron clusters, then spread to the visual thalamus, then to the primary visual cortex. I theorize that each PGO wave creates a new random move that is installed by default in memory in cerebral cortex, and is then tested in the inner theater of dreaming to see what the consequences would be. In the event of a disaster foreseen, the move is scrubbed from memory, or better yet, added as a "don't do" to the store of accumulated wisdom. Repeat all night.

If memory is organized like an AI knowledge base, then each random move would actually be a connection from a randomly-selected but known stimulus to a randomly-selected but known response, amounting to adding a novel if-then rule to the knowledge base. Some of the responses in question could be strictly internal to the brain, raising or lowering the firing thresholds of still other rules.

(Deprecated, Part 3)

In "Evolution in Four Dimensions" [1st ed.] Jablonka and Lamb make the point that epigenetic, cultural, and symbolic processes can come up with something much better than purely random mutations: variation that has been subjected to a variety of screening processes.

Nightmares involving feelings of dread superimposed on experiencing routine activities may serve to disrupt routine assumptions that are not serving you well (that is, you may be barking up the wrong tree).