Zhurnal Vysshei Nervnoi Deyatelnosti Imeni I.P. Pavlova

One-trial learning represents a critical evolutionary mechanism that enables animals and humans to rapidly encode and retain essential experiences, allowing adaptive responses to environmental changes. This article reviews various paradigms of one-trial learning, such as passive avoidance, taste aversion, and contextual fear conditioning, along with models involving associative memory for object location and social transmission of food preferences. These paradigms span a wide variety of species, offering flexibility in terms of ecological validity, sensory modalities, and types of reinforcement. The ability of one-trial learning paradigms to induce memory formation in a single trial provides a powerful advantage for experimental control, minimizing confounding variables and allowing precise separation of memory phases. This makes one-trial learning paradigms especially useful for studying early stages of memory formation, synaptic plasticity, and long-term memory mechanisms. Furthermore, one-trial learning models are advancing the development of innovative treatments for memory-related disorders, including amnesia and post-traumatic stress disorders. Additionally, findings from one-trial learning models could aid in developing artificial intelligence systems that replicate biological memory processes more accurately.

The connection of P300 subcomponents with visual spatial attention remains obscure. In the experiment conducted in three-stimulus «oddball» paradigm we showed that in case of overt attention P300 resembles P3b – it has a longer peak latency and temporo-parietal source localization (lingual and cingulate gyrus, precuneus). Alternatively, in case of covert attention it has frontal localization and a longer peak latency that is similar to P3a and nP3 subcomponents. Our data clarifies the association between P300 and visual spatial attention and may be useful for optimization of P300-based brain-computer interfaces.

Neurorehabilitation of motor functions using a neurointerface (BCI) with feedback is a modern promising area of research. However, there is very little data on muscle activity during the motor imagery of lower limb – an important aspect of rehabilitation. The EMG activity of the lower limb muscles was studied in 42 healthy participants which control BCI, based on kinesthetic motor imagery of dorsiflexion of the feet and supplemented by a robotic device for moving the limbs “Biokin” (mechanotherapy), activated in case of successful motor imagery. It is shown that BCI control leads to an increase in the activity (averaged all over the participants) of the muscle, whose movement provides an imaginary movement in reality – the tibialis anterior (TA). In addition, the activity of the gastrocnemius muscle – the antagonist of TA – increases, which is apparently associated with the instruction to imagine, but not to make a movement. Activation of the mechanical training device (AM) additionally increases TA EMG (up to 100-200%) and weakly but significantly (by 3–5%) reduces the activity of the thigh muscles (quadriceps and left biceps). Therefore, AM increases the targeting of the downward signal that occurs during the motor imagery. Muscle reactions to the motor imagery are individual. Thus, the use of BCI based on the motor imagery of dorsiflexion of the feet and the use of the mechanical training device, which ensures the closure of the feedback loop when imagining this movement, contributes to the targeted activation of TA – the muscle that provides dorsiflexion of the foot, which is important for the clinical rehabilitation of paretic foot movements.

The study examines the neurophysiological correlates of confirmation bias in the context of vaccination using fixation-related potentials (FRPs). A methodological approach integrating eye tracking and electroencephalography (EEG) was employed in a laboratory experiment, enabling the synchronization of eye movement data with the brain’s bioelectrical activity. Participants read texts about vaccination containing positive, negative, and neutral statements, while their reactions were recorded under conditions of congruence and incongruence between the valence of the text and the implicit component of their attitude, measured via the Implicit Association Test. The findings revealed significant differences in neurophysiological responses, including increased potential amplitudes in incongruent conditions for the P200, P300, N350, and N400 components. These responses indicate the activation of selective attention and enhanced perceptual stimulus processing (P200), reallocation of attentional resources and the emergence of cognitive dissonance (P300), emotional categorization (N350), and semantic, including valence-related, mismatch processing (N400). The results underscore the high sensitivity of FRP methods to the cognitive and emotional aspects of information perception. The proposed methodological approach enhances the ecological validity of the study, offering promising opportunities for investigating implicit cognitive processes in naturalistic text perception settings.

Social isolation is a mild stressor and prolonged exposure to this stressor leads to the development of mental disorders and an increase in mortality from various causes, especially in the group of older people. In animals, social isolation also has a stressful effect. In the present study we investigated the effect of long-term isolation on non-associative learning in outbred Wistar rats and genetically related normotensive rats of the WKY strain and spontaneously hypertensive rats of the SHR strain. Nine-ten-month-old male rats were used for the study. Some animals were placed in individual cages, and the other part was left in home cages under group maintenance. Non-associative learning (habituation) was studied in the “open field” test. Short-term habituation was assessed using indices of locomotor activity and the number of rearing during the first session. Long-term habituation was assessed after a repeated test performed 96 h later on. It was found that in Wistar rats, isolation disrupted both short-term and long-term habituation. In WKY rats, short-term habituation was observed, and long-term habituation was impaired. In SHR rats, non-associative learning was completely disrupted. Prolonged isolation did not have a significant effect on the behavioral indices studied in WKY and SHR rats. Thus, hypertension in SHR rats was accompanied by an impairment of non-associative learning. Isolation caused disruption of non-associative learning in Wistar control rats, but did not affect this type of learning in rats of genetically related WKY and SHR strains.