MAD saccade: statistically robust saccade threshold estimation via the median absolute deviation

Saccade detection is a critical step in the analysis of gaze data. A common method for saccade detection is to use a simple threshold for velocity or acceleration values, which can be estimated from the data using the mean and standard deviation. However, this method has the downside of being influenced by the very signal it is trying to detect, the outlying velocities or accelerations that occur during saccades. We propose instead to use the median absolute deviation (MAD), a robust estimator of dispersion that is not influenced by outliers. We modify an algorithm proposed by Nyström and colleagues, and quantify saccade detection performance in both simulated and human data. Our modified algorithm shows a significant and marked improvement in saccade detection - showing both more true positives and less false negatives – especially under higher noise levels. We conclude that robust estimators can be widely adopted in other common, automatic gaze classification algorithms due to their ease of implementation

Evaluation methods of α and β2-adrenoreactivity of human erythrocytes to change their osmotic resistance under the effect of adrenaline and adrenoblockers

According to the data of literature the main evaluation methods of α and β2-adrenoreactivity of human erythrocytes have been described to change their osmotic resistance under the effect of adrenaline and blockers. Nowadays β-blockers are used in many cardiac diseases to prevent sudden cardiac death. They are acute coronary syndromes, chronic coronary heart disease (CHD), arterial hypertension (AH), arrhythmias, congestive heart failure (CHF), hypertrophic cardiomyopathy, mitral valve prolapse. β-blockers are also used in such diseases and syndromes as migraine, glaucoma, thyrotoxicosis. The article presents the results of a study of evaluation methods to identify functional changes, diagnosis and prognosis of chronic cerebral ischemia of hypertensive genesis of different stages. That’s why the author applied a complex approach. It based primarily on the fact of inhibition of hemolysis of erythrocytes placed in the hyposmotic medium in the presence of beta-blocker, on visual fixation of the change of erythrocyte aggregation under the effect of adrenaline and other adrenergic agents, and on the registration of changes in osmotic resistance of erythrocytes under the influence of β-adrenoblockers. According to the results the indicators of these methods of evaluation of beta-adrenoreactivity allow to differentiate the stages of the disease at the cellular level quickly and reliably. They depend on the physiological state and patients’ sex. The indicators can also be an objective criterion for assessing the effectiveness of treatment and optimize approaches to prevent progression of cerebral circulation disorders

Iнварiантнi поверхнi для певних класiв систем другого порядку стохастичних диференцiальних рiвнянь зi стрибками

In this paper, we consider the concept of invariant sets of inhomogeneous stochastic differential equations with jumps. For certain classes of systems of the second order of inhomogeneous stochastic differential equations with jumps the necessary and sufficient conditions for the invariance of the corresponding surfaces are established. The obtained results provide opportunities to find the invariant surfaces and conditions of their invariance for the specified classes of stochastic differential equations. Pages of the article in the issue: 22 - 27 Language of the article: UkrainianУ статтi розглядається поняття iнварiантних множин неоднорiдних стохастичних диференцiальних рiвнянь зi стрибками. Для певних класiв систем другого порядку неоднорiдних стохастичних диференцiальних рiвнянь зi стрибками знайдено необхiднi i достатнi умови iнварiантностi вiдповiдних поверхонь. Отриманi результати дозволяють знаходити iнварiантнi поверхнi та умови їх iнварiантностi для вказаних класiв стохастичних диференцiальних рiвнянь. Сторінки у випуску: 11 - 21 Мова статті: українськ

Transformation of the Migration Policy of States During the Pandemic Period

Introduction. The article is devoted to the transformation of migration policies during the COVID-19 coronavirus pandemic. The article discusses changes in migration processes in connection with the COVID-19. The aim of the article is to illustrate how the countries’ migration policy has changed due to the pandemic and what measures have been developed to support migrants. Methods and materials. The research methodology includes general scientific research methods, such as analysis, synthesis, content analysis and the aristotelian method. As well as specific scientific methods, such as comparative legal and system analysis. The empirical basis of the study is the data of the General Administration for Migration Issues of the Ministry of Internal Affairs of Russian Federation, the International Organization for Migration (IOM), and the United Nations (UN). Analysis. The authors conducted a comparative analysis of migration policies of various countries during the COVID-19 coronavirus pandemic. Considerable attention is paid to the measures taken by countries to provide various types of support to migrants. The authors also analyzed the activities of international organizations and the civil society. The authors concluded that measures to restrain the pandemic affected the implementation of funded integration projects in the European countries, some activities were postponed, however, the European countries made certain efforts to adopt new integration practices to support migrants during the COVID-19 pandemic. Discussion. The authors assessed the further development of migration processes and countries migration policies. Results. The authors effectuated a conclusion that the COVID-19 pandemic has had a significant impact on the transformation of migration processes and migration policies. The authors focused on how events in the migration sphere would develop, and what changes would take place in the migration policy of the Russian Federation. The research results presented in the article can be used to improve the migration policy of the Russian Federation in relation to labour migrants and to develop regulatory migration measures

Research of special limits during heat treatment of materials in the two-phase region under supercritical temperature influence

The results of the research on establishing the dependence of the coercive force (Нs) on special boundaries in a low-carbon alloy are given. Annealing at a temperature of 900 °С with a holding time of 1 to 3 h leads to an increase in the number of special boundaries from 22.7 to 37.17% and to an increase in magnetic permeability and, accordingly, a decrease in the coercive force from 1.60 to 1.24 A/cm. When the load is axially stretched, the coercive force changes. The initial stage of plastic deformation is most sensitive to the growth of coercive force, which allows us to identify areas in which local plastic deformation has occurred, which indicates a significant decrease in the operational characteristics of parts.Наведено результати дослідження по встановленню залежності величини коерцитивної сили (Нс) на спеціальні границі в низьковуглецевому сплаві. Відпал при температурі 900 °С з витримкою від 1 до 3 год призводить до збільшення кількості спеціальних границь з 22,7 до 37,17% та до збільшення магнітної проникності й відповідно зниження величини коерцитивної сили з 1,60 до 1,24 А/см. При осьовому розтягуванні навантаження змінюється коерцитивна сила. Початкова стадія пластичної деформації найбільш чутлива до зростання коерцитивної сили, що дозволяє виявити ділянки, в яких сталася локальна пластична деформація, що свідчить про значне зниження експлуатаційних характеристик деталей

Disruption in neural phase synchrony is related to identification of inattentional deafness in real-world setting

Individuals often have reduced ability to hear alarms in real world situations (e.g., anesthesia monitoring, flying airplanes) when attention is focused on another task, sometimes with devastating consequences. This phenomenon is called inattentional deafness and usually occurs under critical high workload conditions. It is difficult to simulate the critical nature of these tasks in the laboratory. In this study, dry electroencephalography is used to investigate inattentional deafness in real flight while piloting an airplane. The pilots participating in the experiment responded to audio alarms while experiencing critical high workload situations. It was found that missed relative to detected alarms were marked by reduced stimulus evoked phase synchrony in theta and alpha frequencies (6–14 Hz) from 120 to 230 ms poststimulus onset. Correlation of alarm detection performance with intertrial coherence measures of neural phase synchrony showed different frequency and time ranges for detected and missed alarms. These results are consistent with selective attentional processes actively disrupting oscillatory coherence in sensory networks not involved with the primary task (piloting in this case) under critical high load conditions. This hypothesis is corroborated by analyses of flight parameters showing greater maneuvering associated with difficult phases of flight occurring during missed alarms. Our results suggest modulation of neural oscillation is a general mechanism of attention utilizing enhancement of phase synchrony to sharpen alarm perception during successful divided attention, and disruption of phase synchrony in brain networks when attentional demands of the primary task are great, such as in the case of inattentional deafness

The detection of phase amplitude coupling during sensory processing

There is increasing interest in understanding how the phase and amplitude of distinct neural oscillations might interact to support dynamic communication within the brain. In particular, previous work has demonstrated a coupling between the phase of low frequency oscillations and the amplitude (or power) of high frequency oscillations during certain tasks, termed phase amplitude coupling (PAC). For instance, during visual processing in humans, PAC has been reliably observed between ongoing alpha (8-13 Hz) and gamma-band (>40 Hz) activity. However, the application of PAC metrics to electrophysiological data can be challenging due to numerous methodological issues and lack of coherent approaches within the field. Therefore, in this article we outline the various analysis steps involved in detecting PAC, using an openly available MEG dataset from 16 participants performing an interactive visual task. Firstly, we localized gamma and alpha-band power using the Fieldtrip toolbox, and extracted time courses from area V1, defined using a multimodal parcelation scheme. These V1 responses were analyzed for changes in alpha-gamma PAC, using four common algorithms. Results showed an increase in alpha (7-13 Hz)-gamma (40-100 Hz) PAC in response to the visual grating stimulus, though specific patterns of coupling were somewhat dependent upon the algorithm employed. Additionally, post-hoc analyses showed that these results were not driven by the presence of non-sinusoidal oscillations, and that trial length was sufficient to obtain reliable PAC estimates. Finally, throughout the article, methodological issues and practical guidelines for ongoing PAC research will be discussed

Functional integration across oscillation frequencies by cross-frequency phase synchronization

Neuronal oscillations and their inter-areal synchronization may be instrumental in regulating neuronal communication in distributed networks. Several lines of research have, however, shown that cognitive tasks engage neuronal oscillations simultaneously in multiple frequency bands that have distinct functional roles in cognitive processing. Gamma oscillations (30-120Hz) are associated with bottom-up processing, while slower oscillations in delta (1-4Hz), theta (4-7Hz), alpha (8-14Hz) and beta (14-30Hz) frequency bands may have roles in executive or top-down controlling functions, although also other distinctions have been made. Identification of the mechanisms that integrate such spectrally distributed processing and govern neuronal communication among these networks is crucial for understanding how cognitive functions are achieved in neuronal circuits. Cross-frequency interactions among oscillations have been recognized as a likely candidate mechanism for such integration. We advance here the hypothesis that phase-phase synchronization of neuronal oscillations in two different frequency bands, cross-frequency phase synchrony (CFS), could serve to integrate, coordinate and regulate neuronal processing distributed into neuronal assemblies concurrently in multiple frequency bands. A trail of studies over the past decade has revealed the presence of CFS among cortical oscillations and linked CFS with roles in cognitive integration. We propose that CFS could connect fast and slow oscillatory networks and thereby integrate distributed cognitive functions such as representation of sensory information with attentional and executive functions.Peer reviewe

A Role of Phase-Resetting in Coordinating Large Scale Neural Networks During Attention and Goal-Directed Behavior

Short periods of oscillatory activation are ubiquitous signatures of neural circuits. A broad range of studies documents not only their circuit origins, but also a fundamental role for oscillatory activity in coordinating information transfer during goal directed behavior. Recent studies suggest that resetting the phase of ongoing oscillatory activity to endogenous or exogenous cues facilitates coordinated information transfer within circuits and between distributed brain areas. Here, we review evidence that pinpoints phase resetting as a critical marker of dynamic state changes of functional networks. Phase resets (1) set a neural context in terms of narrow band frequencies that uniquely characterizes the activated circuits, (2) impose coherent low frequency phases to which high frequency activations can synchronize, identifiable as cross-frequency correlations across large anatomical distances, (3) are critical for neural coding models that depend on phase, increasing the informational content of neural representations, and (4) likely originate from the dynamics of canonical E-I circuits that are anatomically ubiquitous. These multiple signatures of phase resets are directly linked to enhanced information transfer and behavioral success. We survey how phase resets re-organize oscillations in diverse task contexts, including sensory perception, attentional stimulus selection, cross-modal integration, Pavlovian conditioning, and spatial navigation. The evidence we consider suggests that phase-resets can drive changes in neural excitability, ensemble organization, functional networks, and ultimately, overt behavior

Oscillations as a window into neuronal mechanisms underlying dorsal Anterior Cingulate Cortex function

The function of dorsal Anterior Cingulate Cortex (dACC) remains poorly understood. While many methods, spanning bottom-up and top-down approaches, have been deployed, the view they offer is often conflicting. Integrating bottom up and top-down approaches requires an intermediary with sufficient explanatory power, theoretical development, and empirical support. Oscillations in the local field potential (LFP) provide such a link. LFP oscillations arise from empirically well-characterized neuronal circuit motifs. Synchronizing the firing of individual units has appealing properties to bind disparate brain regions and propagate information, including gating, routing, and coding. Moreover, the LFP, rather than single unit activity, more closely relates to macro-scale recordings, such as the electroencephologram and functional magnetic resonance imaging. Thus, LFP oscillations are a critical link that allow for the inference of neuronal micro-circuitry underlying macroscopic brain recordings