The inquiry into how cortical neurons respond to interoceptive signals remains a complex puzzle, central to understanding self-awareness in advanced mammals, including humans. A fundamental aspect under scrutiny is whether neural networks in the cerebral cortex of animals can accurately reflect internal bodily states, particularly cardiac activity. To investigate this, we conducted a study on neurons within the temporal cortex of awake and sleeping cat, employing a unique setup enabling continuous differential recording of local potentials in specific cortical regions, alongside monitoring the cardiogram. Our findings revealed intriguing insights. While the primary auditory cortex (AI) exhibited minimal cellular activity synchronized with heartbeats, the secondary auditory zones within the temporal cortex – the anterior ectosylvian sulcus and the posterior ectosylvian gyrus – displayed synchronization with heart rate. This synchronization was particularly evident in local potentials, with certain neurons within these zones responding to sounds and also exhibiting rhythmic activity aligned with heart contractions. Notably, the complexity of phase histograms derived from the cardiogram period suggests that this synchronization is not attributable to artifacts but rather represents genuine neural responses. Our observations prompt consideration of a hypothesis regarding primary self-awareness in both humans and animals. We propose that this phenomenon emerges from the dynamic interaction of two neural ensembles: one representing external sensory input and the other reflecting interoceptive signals, notably from the heart. This interplay between external and internal stimuli may underpin the fundamental experience of the consciousness of self in highly developed organisms.

The effect of masker on the localization of a sound source in vertical sagittal plane was investigated in simultaneous masking conditions and in the precedence effect paradigm. In the first case, the stationary signal and the masker were presented simultaneously while in the second case the signal onset was delayed relative to the masker onset. The delay was 2, 4, 8, 20, 40, 80 and 200 ms. The signal and the masker were created from two different uncorrelated noise bursts with a bandwidth of 5 to 18 kHz. Duration of noise bursts were 1 s. The masker was placed above the listeners head at an angle of 90 deg and the signal was placed in front of the listener at an angle of 7.5 deg. Perceived positions of signals under masking conditions were compared with those single of the signal or masker presented separately. It is shown that under the masking conditions the probability of detecting a signal decreased. Listeners could localize the signal at the delay of 80 ms and higher. The probability of detecting the signal at 80 ms delay was 92%. The perceived position of signal in masking condition did not significantly differ from the perceived position of single signal. At delays ranging from 0 to 40 ms, listeners mainly showed a perceived masker position that was shifted toward the signal. The shifted position was significantly different from the perceived position of a single masker.

The effect of sensory-cognitive training on features of perception, attention and memory in elderly and senile people was studing. The experimental group included 16 elderly and senile volunteer subjects (average age 73 ±1.7 years) who did not have a history of significant age-related sensory and neurological problems (survey data). All subjects underwent a course of sensory-cognitive exercises for 4 weeks, as well as psychophysical testing and assessment of psychological health resources before and after the training. A significant improvement in target sensory-cognitive indicators (perception, attention, memory) in the experimental group and the dynamics of a number of individual psychological characteristics (anxiety, hierarchy in the value system, vital durability and cheerfulness) were shown. The results allow us to conclude that the developed course of sensory-cognitive training helps to update both the potential of sensory-cognitive processes and the psychological health resources of older people. This indicates the preventive importance of functional training in the context of reducing the age-related risks of developing dementia and achieving the goals of active aging.

The spatial hearing in patients with mild and moderate symmetrical chronic sensorineural hearing loss (SNHL) was studied using the Russian-language version of the Spatial hearing questionnaire (SHQ). 141 patients aged 47 to 82 years were examined. The comparative analysis was performed in the groups of age-related normal hearing, mild SNHL, moderate SNHL. A significant deterioration in spatial perception was shown, revealed by the results of the survey in both groups with SNHL, and the mild and moderate hearing loss groups significantly differed in some indicators. The deterioration of spatial perception revealed by the analysis of the subscales of the questionnaire and the quantitative estimates of spatial and temporal resolution obtained earlier with mild and moderate degrees SNHL were in good agreement. With moderate SNHL, the scores of all four subscales of the questionnaire were significantly reduced. In clinical practice, this questionnaire can be used as a screening method for assessing spatial hearing in patients with SNHL.

To obtain a photo that reproduces the original scene as accurately as possible, it is necessary to solve the problem of color correction, that is, to find a mapping that translates the coordinates of the camera color space (RGB) into the coordinates of the human color space (CIE XYZ). In this article, we consider color correction using lookup tables, pre-built for various lighting conditions. This approach allows you to achieve high speed and accuracy when applying color correction on the device, but requires large amounts of RAM, which, for example, mobile phones do not have. We propose a method for automatic thinning of a set of search tables without loss of accuracy of color correction. The method is based on clustering of the mappings that specify the color correction. To compare the mappings, we propose a criterion for their similarity based on the maximum difference of the generated colors in the target space of a standard CIE XYZ observer. For the proposed criterion, the article provides an effective calculation method and, together with a theorem justifying the correctness of the method.

Phenomena that occur in response to a decrease in support afferentation, such as a reflex decrease in muscle tone, structural changes in the muscular periphery, and impaired coordination of movements, were observed both in microgravity and in ground-based models of its physiological effects, as well as in immobilized patients and the elderly. The discovery of the concept of the trigger role of support afferentation in the activity of postural-tonic muscle system led to the development of methods of the support stimulation as a countermeasure for the motor unloading negative consequences. This review aims to discuss the results of applying the method of mechanical stimulation of the soles support zones to mitigate negative consequences of the support and motor unloading in space and ground-based medical practice.

The article presents a literature review on the human cochlear aqueduct. It describes the anatomy of the cochlear aqueduct that became available using high-resolution computed tomography of the temporal bones, methods for assessing the size of the cochlear aqueduct, types of cochlear aqueducts, and reasons for the occasional lack of visualization of the cochlear aqueduct on computed tomograms. The criteria and validity of the concepts of “wide” and “narrow” cochlear aqueduct, the patency of the cochlear aqueduct and its changes with age, the role of the cochlear aqueduct in the development of purulent inflammation in the structures of the labyrinth of the inner ear, perilymphatic hypertension, and temporary perilymphatic hypotension are analyzed. The literature data show that the existence of an anatomically and functionally wide, or more precisely, excessively patent, cochlear aqueduct is possible. Pathological conditions of the cochlear aqueduct and its interaction with adjacent anatomical structures are discussed. A clinical case of unilateral fluctuating hearing loss is presented, in which a congenital anomaly of the inner ear development was detected on a CT scan – dehiscence between the abnormally large bulb of the jugular vein and the cochlear aqueduct. To assess the contribution of the aqueduct to the pathology of the inner ear, more attention to this anatomical structure and further accumulation of data are required.

In recent decades, the practice of demonstrating various static and video images to users using digital, processor-controlled, most often self-luminous devices (computer monitors, smartphone and tablet screens, etc.) has spurred the development of various methods to improve the perception of such images by means of computerized image preprocessing. This also applies to methods of preprocessing images shown to users with various refractive anomalies of the eye(s) (e.g., myopia or astigmatism) in situations where they are not armed with glasses or other corrective devices. Over the past 20+ years, researchers have published dozens of papers on this task, referred to as the precompensation task. In our opinion, the time has come to reflect on the development of scientific thought in this direction and to highlight the most important milestones in realizing the problems on the way to achieving “ideal” precompensation and in approaches to their successful solution. This is the focus of the first part of this review. In the second part, we focus on the current state of research in the stated area, highlight the problems not solved so far, and try to catch the trends of further development of image precompensation methods, paying maximum attention to neural network approaches.

The article is devoted to the description and analysis of a computer model that was created by D. S. Lebedev to demonstrate the possibility of a positive effect of fixation microsaccadic eye movements on the perception of small stimuli. The model is based on the assumption that in the process of fixing the gaze on the test stimulus, several “neural images” of this stimulus, resulting from microsaccades, are summed up in the brain. The series of summed neural images correspond to a sequence of shifted positions of the optical image of a stimulus on the retina. To accurately superimpose neural images on each other, a mechanism for compensating fixation saccadic microshifts is introduced into the model, identical to the mechanism that ensures the constancy of spatial perception in the case of macrosaccades, i.e. when turning the eyes to view large objects or scenes. The author of the model assessed the possibility of improving the quality of visible images by increasing the signal-to-noise ratio, which can be achieved using realistic spatiotemporal parameters of test images, neural noise and eye micromovements, selected bу means of literature analysis. Results of model calculation obtained for the specific parameters of the retina and eye movements showed that the considered summation mechanism with compensation for saccadic shifts can progressively improve the quality of visible test stimuli when the number of summed neural images increases to approximately seven or eight, after which the positive effect practically does not increase. In this article, based on the material of recordings of eye movements in relevant experiments, the degree of realism of this model is discussed.

A methodical apparatus for creating sensor measurement systems for monitoring human respiration rate is proposed. It includes a method for estimating respiratory rate based on statistical analysis of photoplethysmographic signals (human pulse wave), a method for selecting priority regions for estimating respiratory rate, and a criterion for determining the required bracelet tension during measurements. The application of the respiratory rate estimation method involves calculating the Correntropy spectral density of the pulse wave signal. A distinctive feature of the method is the use of an algorithm for selecting the priority empirical mode of the Hilbert-Huang decomposition, which is most closely related to the respiratory rate. Experimental verification of the method showed that the mean value of the absolute error for 58.8% of the sample of calculated respiratory rate values did not exceed 1 breath/min, and the 95% confidence interval for the mean absolute error of the entire sample was [0.72–2.2] breaths/min.