Gates of Senses: What Do the Relationships Between Our Archaic Olfaction and Evolutionarily Advanced Vision Testify To? Column for Компьютерры #107

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Dmytro Shabanov
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Why We Allow Ourselves to Be Deceived, or Sad Reflections on the Irrationality of Political Life The Gate of Senses: What the Relationship Between Our Archaic Sense of Smell and Our Evolutionarily Advanced Vision Tells Us On the Humanitarian and Natural Science Approach to the Explosive Topic: Discussing the Causes of Homosexual Behavior

Column for Kompyuterra #106 Column for Kompyuterra #107 Column for Kompyuterra #108

In this column, I will touch upon facts and speculations that seem truly intriguing to me. It's a pity that these circumstances, even before we could understand their true meaning, have begun to be widely used in advertising. And then, without fully developing my thoughts, I will cite an example that will help to see the difference between two types of descriptions of our actions. I want to convince you that descriptions based on the picture of reality created by our consciousness and explanations based on the analysis of the functioning of unconscious mechanisms of our behavior do not necessarily contradict each other. I will start by saying that we have no other way of interacting with the world than by analyzing the images created by our senses (we discussed this here, here, and here). Depending on what passes through the gates of our senses, reality (what affects us) is constructed differently for us. However, reality is "created" not only by receptors (perceiving structures) but also by the brain centers that process their signals. The complex of receptor and auxiliary structures, information transmission pathways, and primary processing centers is called an analyzer. Our perception of the world is a consequence of the functioning of our analyzers: visual, auditory, olfactory, gustatory, tactile, and others. The world of a bat or a dolphin is built primarily on the complex perception of echoes, the world of a mole is tactile-olfactory, and the world of a human or a green monkey is formed primarily by visual imagery. Unfortunately, not every human: the world of a blind person turns out to be different. By the way, people blind from birth, after learning echolocation, sometimes turn out to be able not only to walk without a cane but also to ride a bicycle, perceiving obstacles by sound. The Neuro-Linguistic Programming school attaches great importance to which analyzer is dominant in a particular person. These are indeed serious differences, although it seems their significance is often greatly exaggerated. Perhaps this is done for manipulation: "Now I will teach you how to foist your goods on an auditory person, and how on a kinesthetic one!"... I find the analysis of the situations in which the same person acts, for example, visually, and in which aurally, more interesting. I know from personal experience that I am different in a situation of visual dominance than I am in a state of auditory dominance. But that's not the point now. I want to compare the evolutionary age of different analyzers, or more precisely, the time that has passed since their restructuring and, accordingly, since the formation of innate programs that launch their signals. The oldest sense is chemical. In aquatic animals, it is relatively undivided, and upon emerging onto land, it manifests as taste (analysis of substances dissolved in saliva), smell (investigation of volatile molecules in inhaled air), and Jacobson's sense (perception of the smell of objects in the mouth). Do not be surprised: in some animals, the dominant analyzer is associated with the Jacobson's organ. A snake flicking its forked tongue collects aromatic molecules on its surface. Then it brings the tip of its tongue to the Jacobson's organ, which is located in the roof of the mouth, in its anterior part. The analysis of molecules released from the tongue's surface is supposed to create a very specific picture of reality. Probably, the sense of touch is not much younger. Its improvement led to the formation of seismosensory (vibration-sensing) organs, characteristic of aquatic animals. For many fish, the lateral line is one of the main channels of information from the external world. Auditory organs are fundamentally structured the same way. I believe that hearing is closely related to touch (and these senses are homologous, just as different forms of chemical perception are homologous). Vision probably became an important channel for obtaining information from the external world last. Obviously, its importance strongly depends on the lifestyle. Good vision, with detailed color perception, is characteristic of inhabitants of brightly lit environments that allow movement in all three dimensions. It is typical for diurnal coral fish, diurnal flying insects, diurnal arboreal amphibians and reptiles, and, of course, diurnal birds. It remains to add that not all our receptors analyze the external environment. Inside us, there are receptors similar to these, for both external chemical and external tactile sensation... For one group of animals, the gap between the evolutionary age of the relatively "young" vision and the "old" hearing-smell-touch is particularly significant. I am talking about our group - the dry-nosed primates, representatives of the suborder Haplorrhini. We belong to the class Mammalia, i.e., to a group for which vision was not the dominant channel of information acquisition for a long time. Mammals are descendants of mammal-like reptiles that flourished at the end of the Paleozoic era (and probably had good vision then). However, at the beginning of the Mesozoic, mammal-like reptiles were strongly displaced by true (diapsid) reptiles, primarily dinosaurs. Many dinosaurs were diurnal, active animals with good vision; our ancestors adopted a nocturnal lifestyle. At night, eyes are not as useful as during the day: there is little light, and the amount of visual information decreases. Color vision is undesirable at night. A receptor cell that responds to light quanta of any wavelength (within the visible spectrum, of course) will fire more often in low light conditions than one that is selective for different wavelengths. Therefore, in the retinas of most mammals, rods, which provide monochrome vision, predominate over cones, which provide color perception for diurnal animals. Unlike other classes of tetrapods, which have three or four types of cones, most mammals retain only two types - those most sensitive to blue and green. One might say that in their RGB color system, R is lost... This is not all the tricks that typical mammals have resorted to to increase the light sensitivity of their eyes. Do you know why the eyes of cats and dogs glow in the beam of car headlights? Behind their retina, there is a reflective layer, the tapetum. Part of the light that passes through the retina and remains unabsorbed is reflected by the tapetum and returns. The sharpness of the visual image decreases, but light sensitivity increases. Despite all these tricks, typical mammals do not rely heavily on their eyes; smell, hearing, and touch are more important to them. Touch is often associated with long hairs that allow them to perceive the contours of obstacles - vibrissae. Perhaps the early stages of the development of mammalian fur were related to touch, and the heat-insulating role of hair was secondary... One group of mammals drastically changed its lifestyle, adapting to life in trees and returning to diurnal activity. I am talking about primates. In trees, one cannot always rely on touch and smell. If you want to jump to a neighboring branch, you cannot push it, and you cannot even smell it properly, as reconstructing air currents among the branches can be very difficult. This branch must be well observed, and that is why nocturnal primates develop huge light-sensitive eyes, while diurnal ones evolve towards increased visual image sharpness and finer analysis of spectral characteristics. We said that typical mammals lost R receptors - cones that perceive red. Old World monkeys and some New World monkeys (howler monkeys) independently restored this loss. The pigment that provides selective perception of "red" quanta is encoded by different genes with different evolutionary histories in these two groups of monkeys. This example of evolutionary parallelism is discussed by Dawkins in "The Ancestor's Tale" from the wonderful book "The Ancestor's Tale." Now you understand why the primate group to which we belong is called dry-nosed (as opposed to the more primitive, from our point of view, wet-nosed - Strepsirrhini). Wet-nosed primates have a wet nose - well, much like dogs and many other mammals - and this is associated with better development of their sense of smell. We dry-nosed primates have bet on vision. And now you will understand why higher, consciously controlled functions in humans are more closely related to vision, while archaic functions, related to innate programs, show an intimate connection with smell. Here, of course, one must mention the discovery of the Jacobson's (vomeronasal) organ in humans and the pheromonal regulation of our sexual behavior... No, I won't: this story needs to be detailed. I will talk about it another time, and for now, I will just point out one experimentally confirmed fact. A number of experiments have shown that humans can subtly analyze each other's immune markers by smell. This is related to the analysis of MHC molecules - the major histocompatibility complex, a set of molecules located on the surface of cells that signal genetic individuality. We are not consciously aware of these smells, but their perception affects our motivational sphere. For example, numerous "sweaty t-shirt" experiments have shown that both men and especially women are capable of choosing suitable partners (in terms of innate programs) by the smell of sweat. The principles of such a choice are practically unknown to us. Consciousness is almost not involved in such a choice; a person simply experiences an inexplicable emotion at some point... One statistically confirmed rule is the optimal genetic distance between the chooser and the chosen. Not too similar (inbreeding is often harmful), but also not too distant (to avoid problems associated with hybridization of genetically distant partners). Perfume manufacturers like to publish advertising articles about the role of smell in partner selection, but they usually remain silent that the effect of attraction is related to the genetic individuality of partners and can hardly be artificially modeled. And now I will interrupt the story about the role of smells in the action of our innate programs to refer to an example I liked. I am talking about a fragment from Robin Baker's book "Sperm Wars," published on "Snob." A woman who had a steady partner met her old lover. He sought intimacy, she refused... and a few days later, it somehow happened that she agreed. The fact that she became pregnant by her lover might seem like a coincidence if it weren't for the thorough analysis of the sperm wars of her two men conducted by the author of the book. At the link, you will find two descriptions of the events that happened to her. The first is based on the heroine's experiences and conscious decisions, the second on a reconstruction of the battle in her body of hundreds of millions of cells of her partners. Which of these descriptions is correct? Both pictures are true and incomplete. What was reflected in her consciousness (and the consciousness of the men she interacted with) does not take into account the programs that reflect the strategies of organisms and their cells. The picture of sperm wars is incomplete without considering the history of personal relationships in the described love triangle. When I talk about the role of innate programs in our behavior, I am often understood as if I were claiming that the picture perceived by our consciousness is false, and the truth lies in some dark depths (innate motivation system, gene play, etc.). This is not the case; the second picture complements, not refutes, the first. This approach shows more respect for the functioning of our psyche than the traditional humanitarian view, which is primarily concerned with what should be for the triumph of certain ideas. Compare Baker's text with something familiar, for example: "A soldier walks through the city... and the whole street lights up from the girls' smiles. Don't be offended, girls, because the most important thing for a soldier is that his faraway beloved waits!" Does anyone get upset that this song describes not real soldiers and girls, but the wishes of its authors? Does acknowledging the existence of innate programs in us justify actions that we consider immoral? No. There is nothing fatal in these programs. On the contrary, to control one's behavior and achieve truly meaningful goals, one must understand their logic. And it is obvious to me that the reader of Baker will progress further in this understanding than the listener of Shainsky. This is precisely why I plan to continue exploring the vague hints in future columns about how our innate programs work. The conversation about smells has just begun...

←
Dmytro Shabanov
→

Why We Allow Ourselves to Be Deceived, or Sad Reflections on the Irrationality of Political Life The Gate of Senses: What the Relationship Between Our Archaic Sense of Smell and Our Evolutionarily Advanced Vision Tells Us On the Humanitarian and Natural Science Approach to the Explosive Topic: Discussing the Causes of Homosexual Behavior

Column for Kompyuterra #106 Column for Kompyuterra #107 Column for Kompyuterra #108