LN169-93 Approved For Release 2000/08/11 : CIA-RDP96-00792R000500560007-5 psychic act: to this end, he examined known information about the movement of chicks just hatched from eggs after any moving object. We can assume that the possibility of imprinting decreases rapidly with the development of the organism [33] which is due to the biological necessity of concentrating the learning abil- ity during those organism development periods when the role of the acquired habit is optimal [47]. Ethological~physiological—biochemical studies make it possible to speculate that the nervous mechanisms of imprinting are due to the right in- termediate area of the ventral hyperstriatum whereas the contralateral area per— forms the function of translating the imprinting information into a certain un- identified brain structure [43]. It has been established that a significant dif- ference in the distribution character of synaptosomic proteins in the forebrain from that under conventional conditioned reflex learning is observed during im- printing [23]. The reality of quick formation of fixed neurochemical memory codes during imprinting has confirmed the possibility of reproducing imprinting in recipient chicks during the intra-abdominal injection of homogenates of donor chick brain [34]. This is possible only during the first three weeks of develop- ment since during this period, macromolecules can penetrate the brain even through the not-yet-formed hematcencephalic barrier. The authors stress that imprinting can be realized only during the sensitive period which for chicks, is equal to 32~36 h after hatching and can be easily traced by the low pitch sound emitted by the chicks. At the end of this period, an avoidance reaction develops which is accompanied by distress tones, i.e., the sounds of displeasure. It is thought that the amygdaloid complex plays an important role in forming the per-— sistence of memory during single-session learning [22] and it is stressed that the engram activation largely depends on the contextual (emotionally tinted) in- formation available during the presentation of the stimulus being imprinted. It is important to note the difficulty of studying such engrams since they may modi- fy insignificantly yet very stably in time the behavioral patterns of humans and animals and have no crude noticeable manifestations in individual programs [55]. The latter can be attributed to the fact that the researchers do not have an ade— quate logic approach to the imprinting research methodology. An analysis of available data shows that the following is necessary for re- alizing the imprinting: ® a relative sensory deprivation of the individual (in the literal sense, the chick’s stay in the egg); ® a high semantic information gradient (i.e., the degree of its novelty relative to the preceding experiment information which for the chick is literally reduced to the medium volume bounded by nontransparent walls}; and @ a high degree of stress (which is probably characterized by being similar to a daze after information shock). One can clearly see that simple mixing of these factors will by no means facilitate the imprinting of information, so these are identified only for didac~ tic purposes for the sake of understanding subsequent text. In addition to this factor, the absence of any kind of external information editing at the moment of oN, imprinting is extremely important since the system for comparing the memory codes ne, ¥ to the external information codes has not yet been formed. As the memory is be- ing loaded, the correspondence codes will form in the editor and will play the role of identifying the external stimulus and, according to the previous experi-_ ence, initiate various behavioral programs. Any new stimulus which does not have the corresponding codes (i.e., for which there is no similar image in the memory) 7 Approved For Release 2000/08/11 : CIA-RDP96-00792R000500560007-5