Dynamics of second-language learners' semantic memory networks: Evidence from a snowball sampling paradigm.

This article provides an analysis of structural changes in second-language (L2)-based semantic memory networks-graphs composed of L2 words as nodes and semantic relations between them as edges, during L2 learning. We used snowball sampling paradigm to create individual semantic networks of participants divided into two groups differing in L2 learning time and then compare their structural characteristics cross-sectionally. The results showed that as L2 learning progresses, semantic memory networks tend to become more connected (by increasing the average node degree), more efficient (by decreasing the average shortest path length), less fragmented (by decreasing the modularity), less centralized (by decreasing the centralization), less dense (by decreasing the density), and no more "small-worlded" (by similar average clustering coefficients and small-world indices).

Systematic Review and Meta-Analysis of Clinically Relevant Executive Functions Tests Performance after COVID-19.

It is widely known that COVID-19 has a number of prolonged effects on general health, wellbeing, and cognitive functioning. However, studies using differentiated performance measures of cognitive functions are still not widely spread making it hard to assess the exact functions that get impaired. Taking into account the similarities between post-COVID 'brain fog' and chemofog, we hypothesized that executive functions (EF) would be impaired.

Attention and memory after COVID-19 as measured by neuropsychological tests: Systematic review and meta-analysis.

COVID-19 is associated with a range of sequelae, including cognitive dysfunctions as long-standing symptoms. Considering that the number of people infected worldwide keeps growing, it is important to understand specific domains of impairments to further organize appropriate rehabilitation procedures. In this study we conducted a meta-analysis to investigate specific cognitive functions impacted by COVID-19.

Cognitive Resources in Working Memory: Domain-Specific or General?

An experiment in the dual-task paradigm was carried out to explore the nature of domain-specific and domain-general resource distribution in working memory. The subjects (N = 32) performed symmetry span and letter reading span tasks under visuospatial (tapping) and verbal (articulatory suppression) cognitive load. The effects of task type and cognitive load modality were analyzed.

The Impact of Mild COVID-19 on Executive Functioning and Mental Health Outcomes in Young Adults.

COVID-19 is associated with a range of long-lasting symptoms related to cognitive and psycho-emotional spheres. Even mild cases of the disease can lead to persistent cognitive deficits and deterioration of the psycho-emotional state. The purpose of our study was to examine the presence and frequency of psycho-emotional disorders and cognitive deficits in students who recovered from mild form of COVID-19.

[Herpesvirus infections and immunological disturbances in patients with different stages of Alzheimer's disease].

Introduction: Alzheimer's disease (AD) is a multifactorial disease that leads to a progressive memory loss, visualspatial impairments, emotional and personality changes. As its earliest pre-dementia clinical stage, amnestic mild cognitive impairment syndrome (aMCI) is currently considered. Neuroinflammation plays a role in the development and progression of aMCI and the initial stage of AD, which can be supported by immunological disorders of a systemic character.

An experimental paradigm for studying sense of agency in joint human-machine motor actions.

In this paper, we propose an experimental technique for studying the sense of agency (SoA) in joint human-machine actions. This technique is based on the use of an electromechanical finger-lifting device that enables a joint motor action initiated by a participant and completed by the machine. The joint action, later referred to as an "active-passive" action, was implemented as a reaction time task and contrasted with other levels of participant's involvement, including active movement, passive movement, and observation of a dummy's movement.

[Distracter inhibition in mild cognitive impairment].

Objective: To study the effectiveness of interfering visual stimuli inhibition using the flanker task in a group of healthy young and healthy old participants, and in a group of participants with mild cognitive impairment (MCI).

Material And Methods: Reaction times and accuracy, as well as the diffusion model of reaction times with parameters reflecting perceptual and motor processes, stimulus processing speed, and conservativeness of response selection were analyzed.

Results: We found reduced speed and accuracy in older age, especially in MCI patients.

[Features of the conflict adaptation effect in mild cognitive decline.].

Conflict adaptation effect in interference control tasks (like Stroop task or flanker task) consists in better interference suppression in incongruent trials following an incongruent trial. In a flanker task is shown that in normal cognitive aging there is a null conflict adaptation effect and that in mild cognitive impairment there is a reversed (negative) conflict adaptation effect. Using the drift diffusion model of reaction time, it is shown that the change in conflict adaptation effect in mild cognitive impairment is associated with the absence of adaptive increase in processing speed in the presence of distractors.

A passive BCI for monitoring the intentionality of the gaze-based moving object selection.

The use of an electroencephalogram (EEG) anticipation-related component, the expectancy wave (E-wave), in brain-machine interaction was proposed more than 50 years ago. This possibility was not explored for decades, but recently it was shown that voluntary attempts to select items using eye fixations, but not spontaneous eye fixations, are accompanied by the E-wave. Thus, the use of the E-wave detection was proposed for the enhancement of gaze interaction technology, which has a strong need for a mean to decide if a gaze behavior is voluntary or not.

Increased local switch costs in mild cognitive impairment.

Task switching performance was assessed in a group of healthy young, healthy old, and MCI-diagnosed participants. Highly significant RT-related local switch costs were found in the MCI group. This contrasts the typical finding that in normal aging local switch costs show no age-related deficit.

Towards Semantic Brain Mapping Methodology Based on a Multidimensional Markup of Continuous Russian-Language Texts: an Attempt at Validation and Development.

In the present study, we combine linguistic annotation of oral texts in Russian with the registration of BOLD signal in functional MRI experiments to determine how and where semantic categories are represented in the human brain. Using the same stimuli material, we also analyze the differences in cortical activation in three thematic domains: description of nature, description of working principles of technical devices and more self-referential texts, addressing the question of human identity in conflict situations. We discuss methodological problems within the two approaches (microanalysis and macroanalysis) to study brain activation in natural conditions, i.

Size matters: How reaching and vergence movements are influenced by the familiar size of stereoscopically presented objects.

The knowledge about the usual size of objects-familiar size-is known to be a taken into account for distance perception. The influence of familiar size on action programming is less clear and has not yet been tested with regard to vergence eye movements. In two experiments, we stereoscopically presented everyday objects, such as a credit card or a package of paper tissues, and varied the distance as specified by binocular disparity and the distance as specified by familiar size.

Consciousness in a multilevel architecture: What causes the lateralization of effective connectivity under resting state?

Here we present our answers to a critical commentary by Elkhonon Goldberg on our recent publication (Velichkovsky et al., 2018). To avoid discussions about novelty effects in the human brain activity and memory processes, we narrowed down this response to a reanalysis of our data along the lines proposed in the commentary, namely to comparing the effective links between symmetrical brain structures during the first and the last parts of a prolonged resting-state fMRI experiment.

[A role of the immune system in the pathogenesis of schizophrenia].

The review addresses immunological aspects of schizophrenia, a multifactor disease caused by genetic factors, innate disorders of the central nervous system (CNS), including the consequences of perinatal hypoxia and infections, and adverse environmental influences. Neuroinflammation as a part of the pathophysiology of schizophrenia is characterized by the higher transcription of CNS inflammatory mediators, excessive activation of microglia, inhibition of glutamatergic receptors that leads to the decrease in the number of cortical synapses and neuronal apoptosis. The authors discuss a role of genetic polymorphisms of cytokine genes, complement system components etc.

Consciousness in a multilevel architecture: Evidence from the right side of the brain.

By taking into account Bruce Bridgeman's interest in an evolutionary framing of human cognition, we examine effective (cause-and-effect) connectivity among cortical structures related to different parts of the triune phylogenetic stratification: archicortex, paleocortex and neocortex. Using resting-state functional magnetic resonance imaging data from 25 healthy subjects and spectral Dynamic Causal Modeling, we report interactions among 10 symmetrical left and right brain areas. Our results testify to general rightward and top-down biases in excitatory interactions of these structures during resting state, when self-related contemplation prevails over more objectified conceptual thinking.

Gaze3DFix: Detecting 3D fixations with an ellipsoidal bounding volume.

Nowadays, the use of eyetracking to determine 2-D gaze positions is common practice, and several approaches to the detection of 2-D fixations exist, but ready-to-use algorithms to determine eye movements in three dimensions are still missing. Here we present a dispersion-based algorithm with an ellipsoidal bounding volume that estimates 3D fixations. Therefore, 3D gaze points are obtained using a vector-based approach and are further processed with our algorithm.

Consciousness and working memory: Current trends and research perspectives.

Working memory has long been thought to be closely related to consciousness. However, recent empirical studies show that unconscious content may be maintained within working memory and that complex cognitive computations may be performed on-line. This promotes research on the exact relationships between consciousness and working memory.

Comprehensive transcriptome analysis of neocortical layers in humans, chimpanzees and macaques.

While human cognitive abilities are clearly unique, underlying changes in brain organization and function remain unresolved. Here we characterized the transcriptome of the cortical layers and adjacent white matter in the prefrontal cortexes of humans, chimpanzees and rhesus macaques using unsupervised sectioning followed by RNA sequencing. More than 20% of detected genes were expressed predominantly in one layer, yielding 2,320 human layer markers.

Transition to market economy promotes individualistic values: Analysing changes in frequencies of Russian words from 1980 to 2008.

Google Books Ngram was used to assess changes in frequency of usage in words corresponding to collectivistic and individualistic values in Russia during the time of economic changes. It was found that in many domains transition to market economy was associated with a rise in the use of words corresponding to individualistic values and a decrease in the use of words associated with collectivistic values. In several cases, words corresponding to collectivistic terms were used more often than words corresponding to individualistic values.

EEG Negativity in Fixations Used for Gaze-Based Control: Toward Converting Intentions into Actions with an Eye-Brain-Computer Interface.

We usually look at an object when we are going to manipulate it. Thus, eye tracking can be used to communicate intended actions. An effective human-machine interface, however, should be able to differentiate intentional and spontaneous eye movements.

Dynamic Causal Modeling of Hippocampal Links within the Human Default Mode Network: Lateralization and Computational Stability of Effective Connections.

The purpose of this paper was to study causal relationships between left and right hippocampal regions (LHIP and RHIP, respectively) within the default mode network (DMN) as represented by its key structures: the medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), and the inferior parietal cortex of left (LIPC) and right (RIPC) hemispheres. Furthermore, we were interested in testing the stability of the connectivity patterns when adding or deleting regions of interest. The functional magnetic resonance imaging (fMRI) data from a group of 30 healthy right-handed subjects in the resting state were collected and a connectivity analysis was performed.

Changes in snoRNA and snRNA Abundance in the Human, Chimpanzee, Macaque, and Mouse Brain.

Small nuclear and nucleolar RNAs (snRNAs and snoRNAs) are known to be functionally and evolutionarily conserved elements of transcript processing machinery. Here, we investigated the expression evolution of snRNAs and snoRNAs by measuring their abundance in the frontal cortex of humans, chimpanzees, rhesus monkeys, and mice. Although snRNA expression is largely conserved, 44% of the 185 measured snoRNA and 40% of the 134 snoRNA families showed significant expression divergence among species.

Effective Connectivity within the Default Mode Network: Dynamic Causal Modeling of Resting-State fMRI Data.

The Default Mode Network (DMN) is a brain system that mediates internal modes of cognitive activity, showing higher neural activation when one is at rest. Nowadays, there is a lot of interest in assessing functional interactions between its key regions, but in the majority of studies only association of Blood-oxygen-level dependent (BOLD) activation patterns is measured, so it is impossible to identify causal influences. There are some studies of causal interactions (i.

[Macroscopic Functional Networks of the Human Brain when Viewing and Recalling Short Videos].

Macroscopic functional network of the human brain were identified by use of the independent component analysis (ICA) of fMRI while viewing and imaging/recalling stories. The networks were relatively stable in structure, but had a specific dynamics in different experimental conditions. When comparing detected networks with previously detected resting state networks it was found that they coincide on localization.