6.2. Levels of development of the sensory psyche

The lowest level of mental development is characteristic of a sufficiently large number of animals. Among them, the most typical representatives are the simplest. However, there are exceptions in this group. For example, ciliates as fairly highly organized protozoa in the development of the elementary sensory psyche reached a higher level than most of the other protozoa.

The behavior of animals that are at the lowest level of development of the sensory psyche can be extremely diverse, but all manifestations of mental activity in them are still primitive. Mental activity appears in them in connection with the emergence of the ability to feel, feel. It is a sensation, a reaction to the surrounding world, its factors and stimuli that is the elementary form of mental reflection, which is inherent in the simplest. These animals actively interact with the environment, react to its changes. It is important to emphasize that the protozoa not only exhibit certain reactions to changes in the environment that are biologically significant for them, but also react to biologically insignificant factors. In this case, the stimuli that do not directly affect the success of the individual’s life activity act as a signal that marks the appearance of vital for the simplest changes in the environment.

The lower level of development of the sensory psyche is preceded by the level of pre- mental reflection, which is characteristic, for example, of plant organisms. At this stage of development, only irritability processes are inherent in the body. With the achievement of the lower level of development of the sensory psyche, the prepsychic reflection of the simplest does not disappear, its elements are preserved. An example is the reaction of the simplest to such a vital component of the environment as temperature. In this case, we can also talk about the identity of the vital factor and the factor that acts as an indirect signal about the presence of an important environmental factor. The simplest have no specific thermoreceptors responsible for the body's perception of the temperature regime. However, it has long been proven that they exhibit reactions to temperature changes, and they are quite differentiated. So, at the beginning of the XX century. M. Mendelssohn drew attention to the fact that reactions to changes in temperature at infusoria as they approach a certain thermal optimum become more and more differentiated. For example, for infusorium slippers, the optimum water temperature is 24–28 ° C. At temperatures from 6 to 15 ° C, the shoe responds to a temperature difference of 0.06 to 0.08 ° C, and at 20–24 ° C, it reacts to a difference of 0.02 to 0.005 ° C. G. Jennings suggested that the sensitivity of ciliates to changes in temperature is associated with increased sensitivity to this factor of the front end of the body of the simplest. However, experiments with cutting the infusoria into two parts across the body showed that both halves of the body exhibit the same response to temperature fluctuations. It is possible that the reaction of such protozoa to the temperature regime is determined by the properties of the entire protoplasm of the animal. In this case, the reactions may be similar to biochemical reactions, for example, enzymatic processes. Thus, in the simplest, along with mental reflection, the pre-psychic reflection continues to exist, and this is typical both for highly organized representatives of the type (infusoria) and for the low developed ones (for example, eugleins).

Mental reflection and its qualities are determined by the degree of development of the animal's ability to move, as well as to orientation in space and time, to a change in innate behavior.

Modes of movement of the simplest extremely diverse. So, they can soar passively in the water column, and they can actively move. This group of animals has specific modes of movement that are absent in multicellular ones. Examples include movement through the movement of protoplasm and the formation of pseudopodia (typical of amoeba), as well as the “reactive” method of locomotion — mucus is released from the back end of the body under great pressure (inherent to the gregarins). In addition, the simplest may be specialized structures for movement - cilia and flagella. These motor structures are plasmatic processes that perform rotational, oscillatory, and wavelike movements, with the cilia being a more complex effector apparatus than the flagella. Due to the specialization of the ciliary apparatus (the formation of clusters and the merging of several cilia, grouping them in certain areas of the body), the simplest movements can become more complex. For example, infusoria of the genus Stylonychia, along with swimming, can move along the bottom, changing the direction of movement.

The locomotor apparatus of most of the simplest is represented by mionemes - fibers consisting of myofibrils. Mionemes are located in the simplest organism in the form of rings, longitudinal threads or ribbons. They can have both a homogeneous (homogeneous) structure and transverse striation. Mionemes make it possible for the simplest animals to make body contractions, as well as more complex specialized locomotor and non-motor movements. Mionemes are absent in protozoa such as amoebas, rooted knots, an overwhelming number of sporozoans, etc. These protozoa are moved due to contractile processes in the cytoplasm.

All forms of motional activity of protozoa are at the level of instinctive behavior - kinesis (see also 2.3). At the same time, behavioral reactions are carried out in the form of positive or negative taxis, which arise on the basis of sensation and allow the animal to respond adequately to environmental conditions — to avoid adverse conditions and move in the direction of the action of positive and biologically favorable. The instinctive behavior of the simplest is still very primitive, since it is either devoid of the search phase, or this phase is very poorly developed. Mental reflection at this stage is also extremely poor in content, since its content is determined by active search and evaluation of stimuli in the search phase. Search behavior in protozoa exists in the embryonic stage. For example, predatory infusoria are capable of actively searching for victims. However, in general, it can be noted that at the lowest level of the sensory psyche, at a distance, only, as a rule, negative components of the environment are recognized. Biologically neutral factors do not yet have a signal value, therefore they are not perceived by animals from a distance. It can be said that mental reflection at this level of development of the psyche serves exclusively as a “watchman”: biologically insignificant components of the environment are perceived by the body only if they are accompanied by negative biologically significant components.

In the behavior of the simplest, integration in the motor and sensory sphere can be noted. An example is the phenomenon of phobic reaction (fear reaction) in the simplest, for example, in evglen. The simplest, bumping into an obstacle, stops and makes circular movements with the front end of the body. Then the euglena swims away in the opposite direction of the obstacle. Such integration can be carried out with the help of special functional structures that would be similar to the nervous system of multicellular. For the simplest, such structures are found only in infusoria. Perhaps, in addition to this, the system of gradients in protoplasm is involved in the conduction of nerve impulses.

The simplest have a poorly expressed ability to learn. For example, if a ciliate has been swimming for a long time in a triangular vessel along the walls, it retains this trajectory of movement in a vessel of a different shape. As a result of research N.A. Tushmalova in the behavior of ciliates phenomena were found that the researcher interpreted as examples of elementary trace reactions. Thus, ciliates, which were subjected to rhythmic vibration for a long time, initially reacted to this factor by contraction, and after a while they stopped showing reaction. Tushmalova suggested that such trace reactions represent the simplest form of short-term memory, which was formed on the basis of molecular interactions. The question of whether such a behavior change is the simplest form of learning has been discussed by many scientists. Probably, in this case, there is such an elementary form of learning, as addiction. At the lower level of development of the sensory psyche, addiction is based solely on sensations: the animal becomes accustomed to the effects of specific stimuli, which embody specific properties of the environment. At the same time, the animal ceases to appear type-like instinctive reactions in the event that their repetition does not occur biologically significant effect.

The addiction to external manifestations is very similar to fatigue. Unlike the latter, addiction is not connected with the waste of energy reserves, but rather with their savings, with the prevention of energy expenditure on the implementation of biologically useless for animal movements. In experiments with ciliates, fatigue was manifested in the fact that after stimulating the animal with strong stimuli for several hours, it completely ceased to respond to stimuli.

In addition to habituation among highly developed representatives of the simplest, the level of development of the sensory psyche is also characterized by the rudiments of associative learning. In this case, temporary connections are established between the biologically significant stimulus and the biologically neutral stimulus. For example, in the experiments of the Polish scientist S. Vavrzhinchik, the ciliates were taught to avoid swimming in the darkened area of ​​a glass tube filled with water, in which they were irritated by electric current. Gradually, the simplest ceased to swim in the shade even in the complete absence of electric shocks for 50 minutes. Such experiments were later carried out by another Polish researcher, J. Dembowski, who suggested that in this case one can rather talk about the development of primitive conditioned reactions in the infusorium, which is controversial.

As evidence of the ability of ciliates to associative learning, the results of experiments with placing ciliates in capillaries with a curved end were considered. The simplest was placed at this end of the capillary, and then the time it took the ciliates to get out of it was recorded. It is noted that with the repetition of experience, this time significantly decreased. However, later F.B. Applewhite and F.T. Gardner repeated these experiments, and after each experiment the capillary was thoroughly washed. In this case, the exit time after each repetition of the experience did not decrease. Scientists have concluded that the decrease in exit time is not associated with the ability of ciliates for associative learning, but with their orientation in the capillary according to the exchange products accumulated there.

In general, it can be said that the behavior of the simplest is weakly plastic, because it is almost completely determined by the instinctive components, and the possibility of modification lies in the phenomenon of addiction, which cannot yet be called a full-fledged form of learning. The addiction completely provides the necessary for the simplest lability of behavioral reactions. The habitat of the simplest is fairly stable, the accumulation of individual experience is not so important for them, because the life span of the simplest is extremely small.

The highest level of development of the elementary sensory psyche is achieved by the majority of multicellular invertebrates. However, some of them (sponges, the majority of intestinal cavities and inferior worms) are an exception in this regard, their sensory psyche is comparable in terms of their development with the mental development of protozoa. Nevertheless, in general, for all multicellular invertebrates, fundamental changes in behavior can be noted due to the emergence of a special system of coordination of tissues, organs and organ systems - the nervous system. At the same time, the speed of nerve impulses increases significantly: if in the protozoan of the simplest it does not exceed 1–2 μ / s, then already in the primitive nervous system, which has a cellular structure, it increases to a speed of 0.5 m / s. The nervous system of the lower multicellular may have a different structure: mesh (hydra), ring (jellyfish), radial (starfish) and bilateral.

In the process of phylogenetic development, the nervous system plunged into the muscle tissue, and the longitudinal nerve strands became more pronounced, the process of cephalization of the nervous system was observed (the appearance of a separate head end of the body, and with it the accumulation and subsequent consolidation of the nervous structures in the head). In higher worms (ringed), the nervous system takes the form of a “nervous ladder”. Their brain is located above the digestive tract at the anterior end of the body, there are a pharyngeal nerve ring and paired abdominal nerve trunks with symmetrically located nerve ganglia connected by transverse cords. It is in ringed worms that the signs of the highest level of the elementary sensory psyche are fully expressed. It is important to note that the level of mental development is determined not only by the development of the nervous system, but also by the complexity of the conditions of existence of the organism.

The behavior of the ringed worms (kolchets) still does not go beyond the boundaries of the elementary sensory psyche, because it is composed of movements oriented only on certain properties of objects based only on sensations. The capacity for objective perception, i.e., for perception, is still absent in chainmels. It is possible that the beginnings of such abilities appear for the first time in predatory mollusks, as well as in some polychaetes. For example, the land mollusk may begin to bypass the obstacle before it comes into direct tactile contact with it. However, such abilities of the mollusk are also limited: it does not react in this way either to small objects or to too large ones, the image of which occupies the entire retina.

As with the simplest, in the behavior of lower multicellular animals, the avoidance of adverse environmental factors is of paramount importance. However, they also have signs of a higher level of the sensory psyche, that is, they are actively searching for positive stimuli. In the behavior of these invertebrates, along with kinesis and elementary taxis, there are rudiments of complex forms of instinctive behavior (especially in some polychaetes, leeches, and gastropods) and higher taxis appear. Higher taxis provide improved accuracy and efficiency of orientation of the animal in space, as well as the full use of trophic resources. The higher taxis include tropotaxis, telotaxis, menotaxis, and mnemotaxis (for details, see 2.3, pp. 51–52).

In the behavior of higher representatives of the group of multicellular invertebrates, a number of elements are noted which are characteristic of the behavior of more highly organized animals. In polychaetes, unlike other invertebrates, there are complications of type-specific innate behavior, which already go beyond the limits of the elementary sensory psyche. Thus, marine polychaetes are capable of carrying out constructive actions, which are expressed in the fact that worms actively collect material for future structures with the help of bristles, and then they are actively working on the construction of “houses” from it. The construction process is a complex action consisting of several consecutive phases that can be changed, adapting the process to external environmental factors. For example, the structure of the house may vary depending on the nature of the soil and the flow velocity, the bottom relief, the number of particles sinking to the bottom and their composition, and the material for construction may change. Polyheta is actively looking for material for construction, and conducts its selection by size. For example, young worms choose granules of smaller diameter for this purpose, and old animals prefer large particles.

In polychaete, the beginnings of mating behavior and aggression are outlined, which means communication occurs. True mating behavior and aggression begin to develop only at the lowest level of the perceptual psyche (in arthropods and cephalopods) and are characterized by a certain degree of ritualization. However, already in a polychaete (in particular, in the marine worm Nereida) one can observe the struggle for the right to own a house. During such "fights" animals usually do not inflict severe damage to each other, however they bite and can kick an individual out of the house. At the same time, ritualization of behavior and any kind of signaling are completely absent. The aggressive behavior of the male polychaeta with respect to another male during the formation of pairs was noted by CM. Evans and his staff at the sight of Harmothoe imbricata. Marital behavior is noted in gastropods and polychaetes. Так, у виноградных улиток непосредственному спариванию предшествуют длительные «брачные танцы», во время которых партнеры колют друг друга так называемыми «любовными стрелами» – известковыми иглами. Таким образом, высшие формы поведения проявляются в примитивном и зачаточном виде еще на низших стадиях развития психики.

Нервная система низших многоклеточных еще очень примитивна. Ее первичная и основная функция состоит во внутренней координации всех процессов жизнедеятельности организма. Это становится необходимым в связи с развившейся многоклеточностью строения, появлением новых структур, которые должны функционировать согласованно, «внешние» функции нервной системы являются для нее «вторичными». Они определяются степенью внешней активности животного, которая еще очень слаба и редко превосходит активность простейших. Поэтому «внешняя» деятельность нервной системы, а также структура и функции ее рецепторов получают значительное развитие у беспозвоночныех, ведущих активный образ жизни. Как правило, это свободноживущие формы, способные к активному перемещению в среде.

The plasticity of the behavior of the lower multicellular, including the ringed worms, remains low-grade. The behavior is dominated by instinctive components, stereotypical reactions. Individual experience practically does not accumulate, and learning from these invertebrates is extremely weak. Its results are not able to persist for a long time, and it takes a long time to build associative links.

Для всех кольчецов характерно привыкание: после многократного повторения воздействия раздражителя, не сопровождающегося биологически значимым эффектом, врожденная видотипичная реакция животного на этот раздражитель утрачивается. Например, дождевые черви после многократного затенения без неблагоприятных для них эффектов перестают реагировать на это явление стремлением уползти на освещенное место. Привыкание наблюдается не только в двигательной активности, но и в сфере пищевого поведения. Например, проводили эксперименты с хищными кольчатыми червями, которым давали кусочки бумаги, пропитанные соком жертвы кольчеца. Вначале червь несколько раз съедал предложенную бумагу, однако после ряда повторов переставал ее принимать. Эксперимент усложнили: кольчецу давали бумагу и настоящую жертву попеременно, в этом случае после многочисленных повторов червь научался различать объекты, поедая пищу и отвергая бумагу с запахом жертвы. Такие же эксперименты проводились на животных с низшим уровнем элементарной сенсорной психики (кишечнополостными полипами). После нескольких аналогичных повторов полипы также начинали отвергать несъедобные объекты еще до их соприкосновения с ротовым отверстием. Таким образом, низшие беспозвоночные обладают способностями, позволяющими им отличить съедобный объект от несъедобного по побочным физическим качествам. Заметим, что вкусовые качества (прямые физические качества) у обоих объектов были одинаковыми. При определении пригодности в пищу предлагаемого объекта животное ориентируется по его определенному свойству. Это свойство выступает в роли сигнала, а чувствительность животного выполняет роль посредника между жизненно важным компонентом среды и самим организмом. Это свидетельствует о том, что уже на низшем уровне развития у животных появляется психическое отражение в истинном виде.

In flatworms (and more highly developed worms), learning through “trial and error”, as well as the formation of individual motor responses, manifests itself in embryonic form. For example, if you put a strip of sandpaper in the path of the dairy planaria, it stops, but then crawls through the paper. If, however, when crawling, shake the surface of the table, the worm will stop crawling through the paper, even if there is no shaking at the moment. In this case, however, there is still no true, true association of two stimuli, i.e. paper roughness and surface shaking. This effect is due to the general increase in the excitability of the animal, which occurs as a result of a combination of two negative stimuli.

У планарии можно выработать и сложные реакции на два раздражителя, один из которых является для животного биологически нейтральным. Например, Л.Г. Воронин (1908–1983) и Н.А. Тушмалова вырабатывали у плоских (молочная планария) и кольчатых червей оборонительные и пищевые условные рефлексы. Условные рефлексы планарии были крайне примитивны и не сохранялись длительное время, а у полихет они могли самостоятельно восстанавливаться после угасания, обладали достаточной стабильностью. Это свидетельствует о прогрессивном филогенетическом развитии психической активности животных (в частности, червей), которое сопровождается усложнением морфологических, анатомических и функциональных признаков нервной системы.

Пластичность поведения олигохет (малощетинковых червей) исследовалась еще в начале XX в. американским зоопсихологом Р. Иерксом. Он отметил, что для того чтобы научить дождевого червя находить в Т-образном лабиринте «гнездо», а в другом тупиковом конце лабиринта избегать удара током, опыт требуется повторять в течение 120–180 раз. Червей можно переучить, поменяв местами тупики лабиринта с током и «гнездом». Проводились такие эксперименты и с червями, у которых удаляли передние сегменты тела, в этом случае результаты научения не изменялись. V.A. Вагнер сделал вывод о том, что у кольчатых червей ганглии каждого сегмента тела способны к автономной работе по обеспечению выполнения элементарных психических функций. Процесс цефализации у малощетинковых червей еще не достиг такого развития, чтобы определять поведение животного, однако уже на этой стадии развития головной мозг оказывает направляющее воздействие на поведенческие акты. Так, если дождевого червя разрезать поперек тела, задний конец его не сможет передвигаться целенаправленно, тогда как передний будет закапываться в грунт.

Associative links of polychaetes are much stronger. For example, experiments were conducted on changing the sign of the behavioral response of polychaetes to lighting. Under normal conditions, it is negative, but with repeated combination with food reinforcement it can be rebuilt into positive. In this case, when lighting the house, the polychaeta does not hide in its depth, but on the contrary, it actively crawls out of the shelter.