#27. The Origin of Consciousness [neuroscience]

NE

Red, theory; black, fact

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 area on one side of a fractal line and sensory data the area 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.

#21. The Cogs of Armageddon [evolutionary psychology]

EP

Red, theory; black, fact

The Mechanism of Human Dispersal 

How does everyday human behaviour eventually accomplish the biological function of dispersal for the human race? 

Background 

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. 

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.

The Psychology of Dispersal

Human neural pathways may potentiate aggression when the hard times come, but of an elaborate kind featuring many evolved adaptations that ensure efficient dispersal (i.e., with minimal loss of life). 

Our evolved dispersal program begins with a two-person feud of the sort illustrated in cultural references too numerous to mention. An arbitrary stimulus, made offensive by some piece of Pavlovian conditioning, is traded back and forth with rapidly increasing energy. 

Features of Human Dispersal Explained by Evolution 

1) The emotional component is strongly threatening 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.

2) 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.

3) 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 like to do to the other by this point. This, again, is an efficiency from the point of view of producing dispersal.

4) However, if each side is continually threatening the other, why don't they flee each other's presence during the very early stages? Humans may have a reflex that converts feeling threatened into a wish to injure the threatening party, possibly a behavioural leftover from some earlier adaptation, such as an anti-predation defence. To injure, you have to stick around. 

5) Finally, settled refugees usually do not integrate completely into the host society, instead forming ethnic neighbourhoods. Being seen as ethnic by the host society, due to slow integration, could improve the reproductive success of refugees because of disassortative mate-choice effects evolved to favor genes that produce dispersal.

6) The dispersal-producing dynamic just outlined is powerful, because it must overcome all the reasons a person would not leave their 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.

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

EP

Red, theory; black, fact

Statue of Samuel de Champlain, explorer

A Mechanism of Rapid Evolution 

A plausible reason for having a mechanism of rapid evolution is that it permits evolutionary enlargement of body size without loss of evolvability; larger size 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. 

What I call the intermind would be 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 could ensure that the objective function is close to optimal. This group selection process takes place at enormously lower frequencies than those the intermind is tracking, 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.

This genetic intelligence may construct 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 would be 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, 

Its Properties 

The set of ordinary rules or intermind would be 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 would be a distributed intelligence, acting over continental, or a least national, areas. Its objective function, which is simply whatever produces survival, 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.)

Evil Explained

The intermind may account for evil because it is only concerned with survival of the entire species and not with the welfare of individuals.

Evolutionary Mechanisms 

The intermind 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 intermind-related adaptations that facilitate the creation of new species, the units of selection. 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-replacement group selection need act only on the objective function used by trial-and-error processes.

What Are Its Objectives?

In these times, we have come to know 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 (exploration in humans) and optimization of genetic diversity. 

However, all this is insufficient to explain the 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.

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

NE

Red, theory; black, fact

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 Significance of Hemispheric Asymmetry 

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.

Hard-wired hemispheric dominance may be an imperfection of symmetry in the framework of the experimenting brain caused by the human brain being still in the process of evolving, in light of the hypothesis that brain-expanding mutations individually produce small and asymmetric expansions. 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 behaviour.

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.

Motor Control in an Experimenting Brain

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.

In healthy individuals, either hemisphere may control either side of the body, and the laterality of control may 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.

Laterality Control Mechanism

The first bit would be calculated and stored in the basal ganglia. It would be output from the reticular substantia nigra (SNr) and gate sensory input to thalamus to favour 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.

Role of the Corpus Callosum

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.

Brain Mechanism of Operant Conditioning 

Evaluation 

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. 

This arrangement sets up a winner-take-all 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.

Process Control

Each time the cerebral cortex outputs a motor command, a copy would go 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.

Launching an Experiment 

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 interneurons 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.

Coding Analogies 

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. Brodmann Areas 23-24 are classed as limbic system, and areas 31-32 are situated between these and neocortex. This arrangement suggests that, seen as a computer, the brain is capable of executing programs with three levels of indentation. Dynamic changes in hemispheric dominance might occur independently in neocortex, medial cortex, and limbic system.

#5. Why We Dream [neuroscience]

NE

Red, theory; black, fact

The Conjunction of Jupiter and Venus

We Dream Because We Learn

Operant conditioning is the learning process at the root of all voluntary behaviour. 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.)

Learning in the Produce Isle

Operant conditioning 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.  Clearly, common sense plays a role in getting the self-sticky polyethylene bag open for the first time, 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.

How Dreams Help Learning

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 we are 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. 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.  

A Possible Neurobiological Mechanism

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 theatre of dreaming to see what the consequences would be. In the event of a disaster foreseen, the move would be 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.

Support For a Requirement for Vetting 

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.

An Observation and an Exegesis

Oddly, my nightmares happen just after a turn of good fortune for me. However, in our evolutionary past, my kind of good fortune may have meant bad fortune for someone else, and that someone else will now be highly motivated to kill me in my sleep. Unless I have a nightmare and thus sleep poorly or with comforting others. The dream that warned the Wise Men not to return to Herod may have been just such a nightmare, which they were wise enough to interpret correctly. The content was probably not an angelic vision, but more like Ezekiel's valley of dry bones vision in reverse.