The article reports the results of the psychophysiological studies of the perception of conscious and unconscious information during purposeful human activity. The study focused on the most important aspect of sensory physiology—the perception of images. The images contained conscious and unconscious (hidden) faces. We developed the methods of signal (facial images) masking and the methods to identify the person’s unconscious perception through his/her involuntary reactions. We also proposed a set of objective physiological methods of an integrative assessment of a person’s condition. A special focus was given to transferring information along magnocellular and parvocellular neural pathways from the retina to the subcortical nuclei: to the lateral geniculate body, the superior colliculus, the pulvinar, the amygdala complex and the hypothalamus. The article explores how the received information is analysed further in the dorsal occipito-parieto-frontal large-scale neural network and the ventral occipital-temporo-frontal network. It also proposes algorithms that describe how these neural networks function. The markers of unconscious perception were revealed by psychophysiological methods of eye movement registration, EEG and fMRI. The experimental evidence revealed the influence of unconscious perception on decision making in the neural networks of the prefrontal cortex. The article offers a model of opposing interactions of the ventral and dorsal neural networks and reciprocal relationship of the neural networks of various structures of the prefrontal cortex. It has been suggested that the relationship between conscious and unconscious perception ensures decision making and the effectiveness of purposeful human behavior.

The purpose of this study was to investigate the relationship between the morphological parameters of the fovea, foveola, and foveolita of the human eye and the psychophysical and electrophysiological indices of the sensory and cognitive activities. We investigated the relationship between the sizes of these structures and the resolving power of the eye, as well as the influence of the size on the amplitudes and latent periods of various evoked potential components. It has been found that the foveola diameter affects the latent periods of the early waves of the visual evoked potentials (component P 100) in the occipital areas. Our data confirm the effect of the foveola diameter on the parameters of cognitive processes during reading. In particular, it has been found that a larger fovea size provides the perception of a higher amount of printed characters.

The objective of this research was to compare the features of the shape of the foveolar area with the characteristics of eye movements in reading. To measure the size of the fovea, we used the method of optical coherence tomography of the retina. Based on this method, the diameter of the upper part of fovea (fovea diameter) and fovea bottom (foveola diameter) were determined. We found a negative correlation between the fovea diameter and fixation duration and positive correlations at the level of tendency between the foveola diameter and the number of saccades performed and between the foveola diameter and the number of characters captured by eye per fixation.

Biederman et al. [1, 2] have shown that the priming effect does not depend on the difference between the angular sizes of the test stimulus and the primer. However, these two and other similar studies investigated only a small range of the angular sizes of stimuli. Vakhrameeva et al. [3] have shown that there exist two perceptionally different size ranges: perception of the objects with an angular size varying between 1–1.5 and 50 degrees was found to be invariant, but for the objects whose angular size is less than 1–1.5 degrees, their perception is no longer invariant. In this study, the presence of the priming effect has been investigated in the match-to-sample task with such a difference in the angular sizes of the primer and test stimuli that the sizes of the primer (about 4 degrees) and the test stimulus (about 0.5 degrees) belonged to two different size ranges. The sample stimulus was presented with and without noise superposition. It has been shown that the priming effect is suppressed when the size difference between the primer and the test stimulus is large. A congruent primer can have a positive impact on the recognition of the test objects, but this occurs under the viewing conditions complicated by noise superposition.

The fovea and foveola sizes vary across individuals, but it also depends on the method of measurements. Some of the methods investigates functional characteristics to detect the size of the fovea, foveola and other regions of macula. The other methods are morphological. In practical medicine researchers usually need to detect key objects of the retina, like fovea, blood vessels, optic disk to locate changes of the retina related to a particular disease on surface for further treatment. For this purpose they usually use the fundus images. In this research we used line scans and 3D Macular scans to obtain the image of the macula region of human retina. We measured diameters of the fovea and foveola regions and compared these characteristics with human visual performance in different tasks. We showed, that anatomical characteristics of the fovea (fovea and foveola diameters) affect recognition of the small objects. This dependence has been approved using visual evoked potentials methods. Supported by Russian Science Foundation (№14-15-00918).

It is well known that an important function of binocular vision is to increase the SNR. When a signal simultaneously arrives along two channels, it is summed if the channels are statistically independent. The binocular visual acuity can then theoretically be increased by comparison with the monocular value by a factor of 2, or 1.4. This paper gives the results of experiments to measure the visual acuity by means of Landolt rings. It is established that binocular visual acuity is greater than monocular by a factor of 1.3 on the average. It is assumed that this can be associated with internal multiplicative discretization noise at the level of the retinal receptors. This result is important for understanding image processing in different channels of the visual system.

The work of an operator in solving two classification problems when working with one image alphabet is studied. From ninety visual stimuli, half of the images contained animate objects, and the other half contained inanimate objects. The first task was to classify the images according to a semantic attribute—whether they contained an animate or inanimate object. This alphabet of stimuli was then subjected to wavelet filtering in a low- and high-spatial-frequency region, regardless of semantic significance. The second task was to classify the stimuli according to a physical attribute—a blurred or unblurred object in the image. Electrophysiological monitoring of the operator’s work—recording of the induced visual potentials from the entire surface of the head—made it possible to detect that, from the beginning of the stimulation until the organization of the motor response, parallel processing of the observed signal occurs according to the different semantic and physical attributes. The responses of the temporal and frontal sections of the brain associated with the semantics of the images are distinguished, even under those conditions in which the subject’s task was to classify the physical properties of an image of an object.

Biederman and co-authors (1992, 2001), has shown that the priming effect in the long-time priming paradigm does not depend on the difference in the angular size between the test stimulus and primer. However, in this and in other similar works both with long-time and short-time priming paradigms only a small range of sizes has been studied. In the paper of Vahrameeva et al. (2008), it has been shown that there are two physiologically different size ranges: the size of the objects from 1-1.5 to 50 deg perceived invariant to their angular size, and with a size less than 1-1.5 deg (depending on object class and task) their perception ceases to be invariant. We have investigated the safety of priming effect in match-to-sample task with such a difference in angular size of primer and test stimuli, when the size of the primer (about 4 deg) and test stimulus (about 0.5 deg) lie in different physiological size ranges. The sample stimulus was presented with noise superposition or without it. It has been shown that when the difference in sizes is large the priming effect is reduced. Congruent primer can have a positive impact on the recognition of test objects, but only under very difficult viewing conditions (noisy object is presented) and only in reaction times, but not in performance. Supported by grant № 14-15-00918 from Russian Scientific Foundation, Pavlov Institute of Physiology

Методами цифрового синтеза изображений созданы системы тестов для измерения функционального состояния различных уровней зрительной системы, включая высшие когнитивные процессы. Для оценки реакций мозга на синтезированные тесты использовали психофизические методы измерения и функциональную магнитно-резонансную томографию (фМРТ). Особое внимание уделено клиническим аспектам исследования зрительной коры и ее взаимодействия с другими отделами мозга: с теменной, префронтальной, фузиформной и поясной корой. В рамках комплексного исследования при помощи фМРТ осуществлено определение остроты зрения, контрастной чувствительности, поля зрения, распознавание тестовых изображений разной сложности, в частности лиц, а также проведено исследование механизмов избирательного внимания, принятия решений и подготовки двигательного ответа.

В работе исследовали изменение характера движений глаз в процессе чтения текстов, изображения которых были подвергнуты цифровой фильтрации при помощи вейвлетов. Были получены данные, демонстрирующие зависимость характера движений глаз от пространственно-частотной структуры тестовых изображений. Для объяснения полученных результатов рассмотрена роль магно- и парвосистем в обработке зрительной информации в пределах зрительного поля.

Цель исследования - сравнить индивидуальные особенности формы фовеолярной области с психофизиологическими характеристиками зрительного восприятия в условиях помехи. Для получения размеров фовеа применен метод оптической когерентной томографии (ОКТ) сетчатки глаза. Мы использовали этот метод для определения диаметров нижней и верхней части центральной ямки, что соответствует диаметрам фовеолы и фовеа. В психофизической части исследования испытуемым с нормальной остротой зрения предлагали определить ориентацию разрыва в стилизованном элементе Ландольта. Размеры стимулов варьировали от нескольких угл. мин. до 1 угл. град. Изображения предъявляли в условиях помехи, уровень которой варьировали от 0 до 50% (максимального значения). Регистрировали долю правильных ответов в задаче 4-аль-тернативного выбора. При отсутствии помехи доля правильных ответов зависела от размера стимула. При добавлении помехи ухудшалось распознавание даже стимулов большого размера. При максимальном шуме в 50% доля правильных ответов для стимулов всех размеров была на уровне случайного гадания и составляла 25%. Мы сопоставили индивидуальные особенности геометрии фовеа с вероятностью правильного распознавания стимула при наличии помехи. При определенных параметрах стимула обнаружили зависимость вероятности правильного ответа от диаметров фовеолы и фовеа. В пороговых условиях распознавания вероятность правильного ответа для стимула маленького размера линейно зависит от диаметра фовеолы