. This paper presents a novel rodent avoidance test. We have devel-oped a specialized device and procedures that expand the possibilities for exploration of the processes of learning and memory in a psychophysiological experiment. The device consists of a current stimulating electrode-platform and custom software that allows to control and record real-time experimental pro-tocols as well as reconstructs animal movement paths. The device can be used to carry out typical footshock-avoidance tests, such as passive, active, modified active and pedal-press avoidance tasks. It can also be utilized in the studies of prosocial behavior, including cooperation, competition, emotional contagion and empathy. This novel footshock-avoidance test procedure allows flexible current-stimulating settings. In our work, we have used slow-rising current. A test animal can choose between the current rise and time-out intervals as a signal for action in footshock avoidable tasks. This represents a choice between escape and avoid-ance. This method can be used to explore individual differences in decision-making and choice of avoidance strategies. It has been shown previously that a behavioral act, for example, pedal-pressing is ensured by motivation-dependent brain activity (avoidance or approach). We have created an experimental design based on tasks of instrumental learning: pedal-pressing in an operant box results in a reward, which is either a piece of food in a feeder (food-acquisition behavior) or an escape-platform (footshock-avoidance behavior). Data recording and analysis were performed using custom software, the open source Accord.NET Framework was used for real-time object detection and tracking.
Neurofeedback has begun to attract the attention and scrutiny of the scientific and medical mainstream. Here, neurofeedback researchers present a consensus-derived checklist that aims to improve the reporting and experimental design standards in the field.
Objective. The rapidly developing paradigm of closed-loop neuroscience has extensively employed brain rhythms as the signal forming real-time neurofeedback, triggering brain stimulation, or governing stimulus selection. However, the efficacy of brain rhythm contingent paradigms suffers from significant delays related to the process of extraction of oscillatory parameters from broad-band neural signals with conventional methods. To this end, real-time algorithms are needed that would shorten the delay while maintaining an acceptable speed-accuracy trade-off. Approach. Here we evaluated a family of techniques based on the application of the least-squares complex-valued filter (LSCF) design to real-time quantification of brain rhythms. These techniques allow for explicit optimization of the speed-accuracy trade-off when quantifying oscillatory patterns. We used EEG data collected from 10 human participants to systematically compare LSCF approach to the other commonly used algorithms. Each method being evaluated was optimized by scanning through the grid of its hyperparameters using independent data samples. Main results. When applied to the task of estimating oscillatory envelope and phase, the LSCF techniques outperformed in speed and accuracy both conventional Fourier transform and rectification based methods as well as more advanced techniques such as those that exploit autoregressive extrapolation of narrow-band filtered signals. When operating at zero latency, the weighted LSCF approach yielded 75\% accuracy when detecting alpha-activity episodes, as defined by the amplitude crossing of the 95th-percentile threshold. Significance. The LSCF approaches are easily applicable to low-delay quantification of brain rhythms. As such, these methods are useful in a variety of neurofeedback, brain-computer-interface and other experimental paradigms that require rapid monitoring of brain rhythms.
This study explored the effect of the perceived social content of affective pictures on the subjective evaluation of affective valence and arousal. For this purpose, we established three categories of social content (pictures without people, with one person and with two or more people). A sample of 161 subjects rated 200 pictures varying in affective valence (unpleasant, neutral, and pleasant), arousal and social content. Results of two-factor analysis of variance, F(4, 157) = 71.7, p < .001, ηp2 = .31, showed that perceived social content influenced the ratings of affective valence, specially for unpleasant pictures, with the greatest social content (two or more people) leading subjects to rate unpleasant pictures with the lowest ratings (all pairwise comparisons’ p < .001). Regarding arousal, F(4, 157) = 64.0, p < .001, ηp2 = .29), the higher the social content, the higher the arousal ratings, but only for pleasant (all pairwise comparisons’ p < .007) and unpleasant (all pairwise comparisons’ p < .001) pictures. Overall, this study demonstrated an effect of the perceived social content on the subjective evaluation of affective valence and arousal of emotional stimuli.
The aim of our work was to study the influence of the different brain rhythms (i.e. theta, beta, gamma ranges with frequencies from 5 Hz to 80 Hz) on the ultra slow oscillations (USOs with frequency of 0.5 Hz and below), where high and low activity states alternate. The USOs is usually observed within neural activity in the human brain and in the prefrontal cortex in particular during rest. The USOs are considered to be generated by the local cortical circuitry together with pulse-like inputs and neuronal noise. Structure of the USOs shows specific statistics and their characteristics has been connected with cognitive abilities, such as working memory performance and capacity. In our study we used the previously constructed computational model describing activity of a cortical circuit consisting of the populations of pyramidal cells and interneurons. This model was developed to mimic global input impinging on the local PFC circuit from other cortical areas or subcortical structures. The studied the model dynamics numerically. We found that frequency increase deferentially lengthens the up states and therefore increases stability of self-sustained activity with oscillations in the gamma band. We argue that such effects would be beneficial to information processing and transfer in cortical networks with hierarchical inhibition.
Aim of the work was to study the influence of different brain rhythms (i.e. theta, beta, gamma ranges with frequencies from 5 to 80 Hz) on the ultraslow oscillations with frequency of 0.5 Hz and below, where high and low activity states alternate. Ultraslow oscillations are usually observed within neural activity in the human brain and in the prefrontal cortex in particular during rest. Ultraslow oscillations are considered to be generated by local cortical circuitry together with pulse-like inputs and neuronal noise. Structure of ultraslow oscillations shows specific statistics and their characteristics has been connected with cognitive abilities, such as working memory performance and capacity. Methods. In the study we used previously constructed computational model describing activity of a cortical circuit consisting of the populations of pyramidal cells and interneurons. This model was developed to mimic global input impinging on the local prefrontal cortex circuit from other cortical areas or subcortical structures. The model dynamics was studied numerically. Results. We found that frequency increase deferentially lengthens the up states and therefore increases stability of self-sustained activity with oscillations in the gamma band. Discussion. We argue that such effects would be beneficial to information processing and transfer in cortical networks with hierarchical inhibition.
Gamma rhythm (20-100 Hz) plays a key role in numerous cognitive tasks: working memory, sensory processing and in routing of information across neural circuits. In comparison with lower frequency oscillations in the brain, gamma-rhythm associated firing of the individual neurons is sparse and the activity is locally distributed in the cortex. Such “weak” gamma rhythm results from synchronous firing of pyramidal neurons in an interplay with the local inhibitory interneurons in a "pyramidal-interneuron gamma" or PING. Experimental evidence shows that individual pyramidal neurons during such oscillations tend to fire at rates below gamma, with the population showing clear gamma oscillations and synchrony. One possible way to describe such features is that this gamma oscillation is generated within local synchronous neuronal clusters. The number of such synchronous clusters defines the overall coherence of the rhythm and its spatial structure. The number of clusters in turn depends on the properties of the synaptic coupling and the intrinsic properties of the constituent neurons. We previously showed that a slow spike frequency adaptation current in the pyramidal neurons can effectively control cluster numbers. These slow adaptation currents are modulated by endogenous brain neuromodulators such as dopamine, whose level is in turn related to cognitive task requirements. Hence we postulate that dopaminergic modulation can effectively control the clustering of weak gamma and its coherence. In this paper we study how dopaminergic modulation of the network and cell properties impacts the cluster formation process in a PING network model.
Inhibition of return (IOR) represents a delay in responding to a previously inspected location and is viewed as a crucial mechanism that sways attention toward novelty in visual search. Although most visual processing occurs in retinotopic, eye-centered, coordinates, IOR must be coded in spatiotopic, environmental, coordinates to successfully serve its role as a foraging facilitator. Early studies supported this suggestion but recent results have shown that both spatiotopic and retinotopic reference frames of IOR may co-exist. The present study tested possible sources for IOR at the retinotopic location including being part of the spatiotopic IOR gradient, part of hemifield inhibition and being an independent source of IOR. We conducted four experiments that alternated the cue-target spatial distance (discrete and contiguous) and the response modality (manual and saccadic). In all experiments, we tested spatiotopic, retinotopic and neutral (neither spatiotopic nor retinotopic) locations. We did find IOR at both the retinotopic and spatiotopic locations but no evidence for an independent source of retinotopic IOR for either of the response modalities. In fact, we observed the spread of IOR across entire validly cued hemifield including at neutral locations. We conclude that these results indicate a strategy to inhibit the whole cued hemifield or suggest a large horizontal gradient around the spatiotopically cued location.
Paired-pulse transcranial magnetic stimulation (TMS) allows investigating inhibitory and excitatory interactions in the human motor cortex noninvasively. Short-interval intracortical inhibition (SICI) and facilitation (SICF) are used to measure cortico–cortical excitability in patients with, e.g., stroke, dystonia, and Parkinson’s disease. However, the role of the induced electric field (E-field) orientation remains partly unclear. Posterior–anterior (PA)-oriented E-field elicits motor evoked potentials (MEPs) with the lowest stimulus intensities due to the recruitment of corticospinal neurons, indirectly via excitatory synaptic inputs to corticospinal axons (indirect (I-) waves). Stimulation in the lateral–medial (LM) orientation directly activates corticospinal axons, which leads to the generation of both direct (D-) and I-waves. Conditioning stimulus (CS) with an intensity between 50% and 90% of resting motor threshold (RMT) induces activation of GABAA inhibitory mechanisms observed as the SICI (inhibitory) effect on MEP amplitude. In contrast, if the CS intensity is above RMT, the SICF (excitatory) phenomenon can be present due to the superposition of D- and I-waves. Our aim was to investigate the dependence of inhibitory and facilitatory mechanisms on the orientation of the induced E-field of CS and TS. We developed a multi-locus TMS (mTMS) transducer, which allowed us to control the E-field orientation independently for CS and TS at a millisecond inter-pair interval (IPI). Eight healthy subjects (five males; mean age 29, range 21–35 years) participated in the study. mTMS was applied to the hotspot of the abductor pollicis brevis (APB) muscle in the left primary motor cortex. The stimulus intensities were based on the individual RMT of APB for PA and LM orientations. TS and single pulses were administered at 110% RMT. Twenty single pulses were applied for each TS orientation and for each of the 32 paired-pulse conditions. CS and TS stimuli were applied in every combination of the PA and LM orientations with four CS intensities (50, 70, 90, and 110% RMT) and two IPIs (1.5 and 2.7 ms) in a random order. Interaction between CS orientation, IPI, and CS intensity significantly affected TS MEP amplitudes. We observed no statistically significant difference between the responses induced by PA- and LM-oriented TS. CS at 70% RMT for SICI and at 110% RMT for SICF induced similar effects regardless of the TS orientation. We established that LM-oriented CS at 90% RMT produced a greater inhibition than stimuli at the same intensity in the PA orientation. Our results emphasize the minimal influence of the CS E-field dorientation on the test pulse. Additionally, we demonstrate the pivotal role of the stimulus intensity for any CS orientation. SICI and SICF evoked using perpendicular CS and TS directions indicate that we stimulated overlapping neuronal populations with both pulses.
The concept of regression is considered with an emphasis on the differences between the positions of Freud and Jung regarding its significance. The paper discusses the results of experimental analyses of individual experience dynamics (from gene expression changes and impulse neuronal activity in animals to prosocial behaviour in healthy humans at different ages, and humans in chronic pain) in those situations where regression occurs: stress, disease, learning, highly emotional states and alcohol intoxication. Common mechanisms of regression in all these situations are proposed. The mechanisms of regression can be described as reversible dedifferentiation, which is understood as a relative increase of the representation of low-differentiated (older) systems in the actualized experience. In all of the cases of dedifferentiation mentioned above, the complexity of the systemic organization of behaviour significantly decreases.
Variability in beat-to-beat heart activity reflects the dynamics of heart-brain interactions. From the positions of the system evolutionary theory, any behaviour is based on simultaneous actualization of functional systems formed at different stages of phylo- and ontogenesis. Each functional system is comprised by neurons and other body cells, the activity of which contributes to achieving an adaptive outcome for the whole organism. In this study we hypothesized that the dynamics of spectral parameters of heart rate variability (HRV) can be used as an indicator of the system mismatch observed when functional systems with contradictory characteristics are actualized simultaneously. We presented 4–11-year-old children (N = 34) with a set of moral dilemmas describing situations where an in-group member achieved optional benefits by acting unfairly and endangering lives of out-group members. The results showed that LF/HF ratio of HRV was higher in children with developed moral attitudes for fairness toward out-groups as compared to children who showed preference for in-group members despite the unfair outcome for the outgroup. Thus, the system mismatch in situations with a moral conflict is shown to be reflected in the dynamics of heart activity.
Transcranial magnetic stimulation (TMS) is a powerful tool for non-invasive brain modulation and investigation in normal and pathological conditions. One of the most serious problems limiting the TMS use is the high variability of its effects. In recent years, it became widely accepted that the effect of the TMS protocol is not a property of the protocol itself, but a consequence of the interactions of TMS with the neuronal system trait and state. Thus, it is necessary to develop TMS approaches that take into account the ongoing neuronal activity, the so-called state/activity-dependent TMS. This paper presents software that allows considering both the position of the stimulator and the ongoing neuronal activity for TMS triggering. Automatic TMS initiation was demonstrated when all the conditions were met (the beginning of the movement execution, lack of the unnecessary preactivation, the proper coil position). The delay for TMS triggering was tested in an experiment with stimulation triggered by the onset of the desired movement. The development of such technical solution for neuronavigated activity-dependent TMS is important to bring TMS methodology to a new level of its individualized application.
In modern conditions, individualization and optimization of training and additional professional education of a wide range of specialists are increasing in order to strengthen the “personnel base” and solve complex internal and external tasks. Individualized training involves: 1) selecting people according to the criteria of personal predisposition to this type of professional activity; 2) building an adequate system of external training influence within the framework of specialized training and training of personnel. Occupational health and medicine as disciplines and practical areas are faced with the task of using labor as a factor of health and self-development of a person, increasing his vitality, adaptability and professional longevity. The purpose of the study is to identify individual typological profiles, considering professional activity and age, for improving professional selection, development and support of various professions ‘ specializations.
The sample included 389 people (average age–29.5±8.5 years), including 169 participants of the professional community “Institute for development of leaders” and 220 people-extreme specialists. Respondents belonged to the following professional profiles: administrative and managerial; information technology; research and security. The following methodological complex is used: o. SSS; o. TIPI; o. MMPI; o. Grasmika; o. BIS/BAS; o. EPQ; subjective scale for evaluating one’s own entrepreneurial skills.
It was revealed that the combination of a high level of activation system aimed at obtaining additional new stimulation, risk propensity and low emotional stability was characteristic for persons of administrative and managerial profile. Individual and typological characteristics of the security profile were similar to the previous group, except for a lower educational level and pronounced egocentrism. Persons with an information and analytical profile of professional activity were characterized by a low level of activation system and emotional instability. They were prone to risk. Individuals of the research profile were characterized by low self-control, emotional instability when focusing on subjective criteria.
The greatest information content of psychological variables was revealed for the age group from 16 to 21 years. Checking the predictive value of discriminant models, where the target variables were professional activity profiles, revealed the high quality of the model only when the subjects were assigned to the group of the security profile.
The information content of diagnostics of individual typological characteristics for solving problems of predicting behavioral response and professional selection is confirmed. The characteristics of specialists in various professional profiles have predictive value in relation to the risk of disadaptation and decompensation when changing their employment status.
Transcranial magnetic stimulation is a method of focal non-invasive brain stimulation, characterized by high spatial and temporal resolution. To date, diagnostic transcranial magnetic stimulation has been used in clinical practice primarily to assess an involvement of the upper motor neurons and to measure the velocity of the neuronal impulse propagation. However, in the last 10 years, a possible range of transcranial magnetic stimulation diagnostic applications has significantly expanded. Many transcranial magnetic stimulation approaches are coming from scientific laboratories to clinical practice due to an increased availability of transcranial magnetic stimulation equipment, in particular, magnetic resonance imaging navigation for transcranial magnetic stimulation and a combination of the transcranial magnetic stimulation with electroencephalography and also due to an increased awareness of the clinicians. The diagnostic potential of transcranial magnetic stimulation in relation to motor recovery after a stroke can be classified into 4 directions:
1) assessment of the vertical tracts integrity (primarily, the cortico-spinal tract); 2) an assessment of the cortical excitation-inhibition balance;
3) probing of the functional and effective connectivity among brain regions (primarily, cortical convexity and cerebellum);
4) motor mapping to evaluate cortical reorganization.
In this article we will present these 4 directions of the transcranial magnetic stimulation application to study motor system pathophysiology and to predict motor outcome in stroke, including both existing and developing approaches.
Background: Subcultures often develop distinct fashion style, which eventually becomes their “trademark” and represents the culture. In post-soviet countries, “gopniks” are one of the most prominent subcultures that is also present in popular media. Nevertheless, it is unknown to which extent the established image of “gopniks” in common knowledge can influence low-level perceptual processes such as search asymmetry. Objective: Our aim was to examine the influence of specific features of “gopnik” image on visual search. Design: We conducted two experiments to investigate familiarity and threatening of the “gopnik” features. In experiment 1, participants had to find a man-like stimuli in two conditions: a man-like silhouette with vertical stripes on his trousers among similar figures, but with horizontal stripes and vice versa. In experiment 2, participants had to search for the same stripes pattern only (but without man-like silhouette). Conditions were the same as in the first experiment. The experiment 3 was conducted in order to replicate results from previous two experiments with better control. Results: Overall, our results demonstrated visual search asymmetry for man-like (with horizontal stripes on trousers) and gopnik-like (with vertical stripes on trousers) objects, which could not be explained by the basic feature differences of these stimuli. Conclusion: We suggest that nowadays in Russia “gopniks” are perceived as a familiar group rather than dangerous subculture with real power. Their image was successfully transmitted to the general cultural background for post-soviet communities
Understanding neurological mechanisms of motor recovery after stroke is important for selecting appropriate therapeutic and rehabilitation strategies. One of the most widely-used but yet rather controversial MRI predictors is a co-called lesion load on the cortico-spinal tract (CST). This metric corresponds to the overlap between the volumes of the lesion and the cortico-spinal tract which is responsible for conducting neuronal signals that lead to motion generation. In this study we evaluated the potential of the lesion load to explain the motor outcome in a cohort of patients with chronic ischemic stroke. Lesions were automatically identified on structural T1-weighted images using LINDA package. Once lesions are identified, lesion loads on CST were calculated automatically using PALS software package (Ito et al., 2018). Finally, the obtained results were used to classify patients according to their motor outcome using decision tree classifier J48 implemented in WEKA software. However, the classification accuracy was much lower compared to the classification results based on another widely accepted MRI parameter: asymmetry of the fractional anisotropy in the internal capsule of the CST.
The degree of mental attention in childhood and adolescence determines in the future the effectiveness of working memory (ability to store and manipulate information). Attention has been previously found to be related to the prefrontal and parietal areas of the human cortex. But the relationship between attention and white matter properties are still largely unknown. The goal of this study was to identify the relationships between attention and fractional anisotropy (FA) of diffusion MRI in bilateral superior longitudinal fasciculus (in three subdivisions SLF 1- 3), arcuate fasciculus (AF), and corpus callosum (CC) in children and adolescents. Subjects: 14 children (9-11 years) and 13 teenagers (12-15 years). During the experiments participants had to establish a match between the colors on the screen and the colors on the previous slide. The task had six difficulty levels and both performance accuracy (m-score) and reaction time (RT) were measured. There was a positive correlation for m-score and a negative correlation for RT with FA in СС (levels 1-3) in the children's group (p<0.05). On the contrary, when FA increases in the right SLF 3 (level 6), there is a decrease in m-score, and when FA increases in the left SLF 3 and AF, there is an increase in RT at 2,3,4 and 6 levels. In contrast, a decrease in RT with an increase FA of bilateral SLF 3 (level 6) and left AF (level 4) was observed for adolescents, which reflects the redistribution of the roles between fiber tracts with age. FA values of the left (level 2) and right (level 1) SLF 2 negatively correlated with mscore (p <0.05) in the same group. For females (n=13) (regardless the age), there was only a negative correlation for m-score (2,3,5 levels) and the only positive correlation for RT (level 2) with FA of the right SLF 1, left and right SLF 2, in the left SLF 3 and СС (p<0.05). For males (n=13), on the contrary, there were positive correlations between m-score and FA of the СС (1,3,4 levels) and the left SLF 1 (5 level), and inverse correlations between RT and FA for the same fibers of the white matter (1 level) (p<0,05). Interestingly, an increase in FA with age was found in males in all the components of the white matter (p<0.01), except for the СС, and in females, on thecontrary – only in the СС. Further research is needed, taking into account gender, to fully understand the influence of white matter on the development of mental attention.
There are a couple of theories that stand out among various attempts to solve the mind-body problem. They abandoned the convenient belief that there exists an observer-independent reality that is accessed through our experience. This article explores solutions to the mind-body problem proposed by the enactivism and the Interface theory of perception. Both theories embrace a radical critique of realism. Such an approach makes it impossible to integrate their ideas into the existing scientific paradigm. This article argues the necessity and the impossibility of a multidisciplinary shift in existing approaches to realism.
In practical medicine, a diagnostic procedure is used only when it can be interpreted at the individual level. The aim of this work was to systematically investigate the relative and absolute reliability of different TMS motor maps parameters. 18 young healthy male right-handed volunteers were enrolled. Two TMS motor mapping sessions of three right-hand muscles were separated by 6-10 days. The analysis was performed using TMSmap software (http://tmsmap.ru). For reliability assessment, intra-class correlation coefficient (ICC) and smallest detectable changes (SDC) were calculated, while for quantitative comparison of the excitability profiles we used a novel earth mover's distance metrics (EMD), the convergence of the parameters depending on the number of stimuli was estimated.
The anterior cingulate cortex (ACC) is a key structure implicated in the regulation of cognitive control (CC). Previous studies suggest that variability in the ACC sulcal pattern—a neurodevelopmental marker unaffected by maturation or plasticity after birth—is associated with intersubject differences in CC performance. Here, we investigated whether bilingual experience modulates the effects of ACC sulcal variability on CC performance across the lifespan. Using structural MRI, we first established the distribution of the ACC sulcal patterns in a large sample of healthy individuals (N = 270) differing on gender and ethnicity. Second, a participants’ subsample (N = 157) was selected to test whether CC performance was differentially affected by ACC sulcation in bilinguals and monolinguals across age. A prevalent leftward asymmetry unaffected by gender or ethnicity was reported. Sulcal variability in the ACC predicted CC performance differently in bilinguals and monolinguals, with a reversed pattern of structure–function relationship: asymmetrical versus symmetrical ACC sulcal patterns were associated with a performance advantage in monolinguals and a performance detriment to bilinguals and vice versa. Altogether, these findings provide novel insights on the dynamic interplay between early neurodevelopment, environmental background and cognitive efficiency across age.