Mirror System Research Articles

РАССТРОЙСТВА АУТИСТИЧЕСКОГО СПЕКТРА У ДЕТЕЙ: ДИАГНОСТИЧЕСКАЯ ЗНАЧИМОСТЬ ЭЛЕКТРОЭНЦЕФАЛОГРАФИИ

Introduction. Early diagnosis of autism spectrum disorder in children is significant clinical problem due to the ever-increasing incidence of this condition in children. Aim. The aim of the study is a comprehensive analysis of data on the features of the bioelectrical activity of the brain in children with autism spectrum disorders, identification of the electroencephalography significance in the diagnosis of these disorders, including the ability to differentiate their subtypes. Material and Methods. The materials for the review were scientific articles indexed in Russian and international databases (Russian Science Citation Index, Scopus, Pubmed) for the period from 1995 to 2022. Results and discussion. The article presents systematized data related to the analysis of electroencephalograms in children with autism spectrum disorder which is carried out in different ways: visual and quantitative. The authors analyzed the changes in the electroencephalograms obtained using spectral analysis, identifying the functional connections of different areas of the brain, with the implementation of non-linear assessment methods. The theory of «mirror neurons» was discussed in connection with the peculiarities of the sensorimotor rhythm reactivity in children with autism spectrum disorder. Conclusion. The presence of electroencephalographic changes in children with autism spectrum disorders is confirmed, especially in the period from 3 to 12 months, although the degree of the sensitivity of methods for their detection at this stage is insufficient for accurate diagnosis. Dynamic electroencephalographic monitoring should be recommended for children with autistic disorders, especially if subclinical epileptiform activity is detected. It is also worth paying attention to the change in functional rhythms in dynamics. In general, results of electroencephalography are often more informative than neuroimaging methods, which in most cases do not reveal organic brain damage in the presence of obvious developmental disorder in a child. The most promising at present are non-linear methods of electroencephalograms analysis.

Mirror Neuron: The Unit of Imitative Mind and its Clinical Applicability

Mirror Neuron: The Unit of Imitative Mind and its Clinical Applicability

The Role of Mirror Neuron System (MNS) in Autism Spectrum Disorders (ASD)

The Mirror Neuron System (MNS) is a group of specialized neurons that discharge when an individual performs an action or observes another individual performing the same activity. This system is divided into two principal hubs; the premotor area in the frontal lobe and inferior parietal lobule(IPL). Mirror neurons play an essential role fundamentally in human social interaction, such as action observation, imitation, understanding the emotions of others, and a myriad of other sophisticated human behavior and thought processes as well as the theory of mind. Since people with Autism Spectrum Disorders (ASD) have disorders and defects in communication, social interaction, the theory of mind, etc . So it can be suggested that defects in the mirror neuron system (MNS) may be linked to disorders like ASD and also play an essential role in this phenomenon. In this review, we discuss this connection.

A Novel Mirror Neuron Inspired Decision-Making Architecture for Human–Robot Interaction

Inspired by the role of mirror neurons and the importance of predictions in joint action, a novel decision-making structure is proposed, designed and tested for both individual and dyadic action. The structure comprises models representing individual decision policies, policy integration layer(s), and a negotiation layer. The latter is introduced to prevent and resolve conflicts among individuals through internal simulation rather than via explicit agent-agent communication. As the main modelling tool, Dynamic Neural Fields (DNFs) were chosen. Data was captured from human-human experiments with a decision-making task performed by either one or two participants. The task involves choosing and picking blocks one by one from seven wooden blocks to create an alpha/numeric character on a 7-segment. The task is designed to be as generic as possible. Recorded hand and blocks movements were used for developing DNF-based models by optimising parameters using a genetic algorithm. Results show that decision policies can be modelled and integrated with acceptable accuracy for individual performances. In the dyadic experiment, using only individual models without the negotiation layer, the model failed to resolve conflicts. However, with the implementation of a negotiation layer, this problem could be overcome. The proposed decision-making structure based on DNFs is developed and tested for a simple pick-and-place task. However, the main primitive underlying action of this task, pick-and-place, is indeed part of many more complex tasks people perform in their day-to-day life. Paired with the possibility to gradually evolve the architecture by adding new policies on demand, the architecture provides a general framework for modelling decision-making in joint action tasks.

Grapho-motor imitation training in children with handwriting difficulties: A single-center pilot study

Imitation is a crucial process for learning and brain development. It is based on the mirror neuron mechanism and underlies our understanding of actions and the gestures of others. Some researchers hypothesized a possible correlation between a low functioning mirror neuron system (MNS) and developmental coordination disorder, including dysgraphic deficit. However, no studies have verified whether imitation of graphic gestures by exploiting the properties of the MNS could improve handwriting. This study evaluates the effects of imitation training of handwriting in five children with handwriting difficulties aged 8 to 10 years. The training lasted for five months, and was undertaken three times a week, for a total number of 60 sessions for each child. Before and after the training, we evaluated the degree of handwriting impairment using the Concise Evaluation Scale for Children’s Handwriting (BHK). Our results suggest that handwriting imitation training produced a significant qualitative change in the children’s writing, likely due to exercises that stimulated fine motor imitation. Furthermore, the imitation also involved ergonomic and biomechanical aspects relevant to improving imitative writing after observing the model. Each child has therefore reached an adequate level of writing, suggesting the effectiveness of the proposed intervention.

Design and Parameter Identification for a Positioning Platform with a Large Stroke and High Precision for Segmented Mirrors

An active optical system with three segmented mirrors was proposed to verify the co-focus and co-phase progress. In this system, a kind of large-stroke and high-precision parallel positioning platform was specially developed to help support the mirrors and reduce the error between them, which can move in three degrees of freedom out of plane. The positioning platform was composed of three flexible legs and three capacitive displacement sensors. For the flexible leg, a kind of forward-type amplification mechanism was specially designed to amplify the displacement of the piezoelectric actuator. The output stroke of the flexible leg was no less than 220 μm and the step resolution was up to 10 nm. Further, a linear model was established to identify the amplification ratio between the actuator and the flexible leg, which can increase the precision of the positioning platform. Moreover, three capacitive displacement sensors with a resolution of 2.5 nm were symmetrically installed in the platform to accurately measure the position and attitude of the platform. To improve the stability and precision of the platform, particle swarm optimization algorithm was applied to identify the control matrix, which can help the platform achieve ultra-high precision positioning. The results showed that the theoretical matrix parameters had a maximum deviation of 5.67% from the experimental ones. Finally, abundant experiments verified the excellent and stable performance of the platform. The results proved that while bearing the heavy mirror, which is no more than 5 kg, the platform can realize a 220 μm translation stroke and 2.0 mrad deflection stroke, with a high step resolution of 20 nm and 0.19 μrad. These indicators can perfectly cater to the requirements of the proposed segmented mirror system’s co-focus and co-phase adjustment progress.

Development of the multi-directional ablation process using the femtosecond laser to create a pattern on the lateral side of a 3D microstructure

Two-photon stereolithography (TPS) is widely used for the fabrication of various three–dimensional (3D) structures with sub-micron fabrication resolution in a single fabrication process. However, TPS is unsuitable for microstructures with fine-hole patterns. The laser ablation process can be easily drilled, or made holes in various materials. However, in the case of laser ablation, the focal plane of the laser is fixed, which is limited to the processing plane. In this study, a multidirectional ablation process is studied to apply laser ablation to various processing planes of a 3D microstructure fabricated by the TPS process. A 3D hybrid fabrication process with the advantages of both TPS and laser ablation is expected to improve the fabrication efficiency. The 3D hybrid process is proposed based on a single laser source. The microstructure is fabricated using TPS, and the multi-directional ablation process creates a hole in the lateral side of the 3D microstructure. To develop the multidirectional ablation process, the reflecting mirror system should be designed to adaptably rotate the laser focal plane and guide the laser path for the target process plane. Through various examples, we demonstrate the ability of the multi-directional ablation process with various examples.

Study subnetwork developing pattern of autism children by non-negative matrix factorization

Background:As a developmental disorder, the brain networks of autism children show abnormal patterns compared with that of typically developing. The differences between them are not stable due to the developing progress of children. It has become a choice to study the differences of developing trajectories between autistic and typically developing children by investigating the change of each group respectively. Related researches studied the developing of brain network by analyzing the relationship between network indices of the entire or sub brain networks and the cognitive developing scores. Methods:As a matrix decomposition algorithm, non-negative matrix factorization (NMF) was applied to decompose the association matrices of brain networks. By NMF, we can obtain subnetworks in an unsupervised way. The association matrices of autism and control children were estimated by their magnetoencephalography data. NMF was applied to decompose the matrices to obtain common subnetworks of both groups. Then we calculated the expression of each subnetwork in each child’s brain network by two indices, energy and entropy. The relationship between the expression and the cognitive and development indices were investigated. Results:We found a subnetwork with left lateralization pattern in α band showed different expression tendency in two groups. The expression indices of two groups were correlated with cognitive indices in autism and control group in an opposite way. In γ band, a subnetwork with strong connections on right hemisphere of brain showed a negative correlation between the expression indices and development indices in autism group. Conclusion:NMF algorithm can effectively decompose brain network to meaningful subnetworks. The finding of α band subnetworks confirms the results of abnormal lateralization of autistic children mentioned in relevant studies. We assume the results of decrease of expression of the subnetwork may relate to the dysfunction of mirror neuron. The decrease expression of γ subnetwork of autism may be related to the weaken process of high-frequency neurons in the neurotrophic competition.

The widespread action observation/execution matching system for facial expression processing.

Observing and understanding others' emotional facial expressions, possibly through motor synchronization, plays a primary role in face-to-face communication. To understand the underlying neural mechanisms, previous functional magnetic resonance imaging (fMRI) studies investigated brain regions that are involved in both the observation/execution of emotional facial expressions and found that the neocortical motor regions constituting the action observation/execution matching system or mirror neuron system were active. However, it remains unclear (1) whether other brain regions in the limbic, cerebellum, and brainstem regions could be also involved in the observation/execution matching system for processing facial expressions, and (2) if so, whether these regions could constitute a functional network. To investigate these issues, we performed fMRI while participants observed dynamic facial expressions of anger and happiness and while they executed facial muscle activity associated with angry and happy facial expressions. Conjunction analyses revealed that, in addition to neocortical regions (i.e., the right ventral premotor cortex and right supplementary motor area), bilateral amygdala, right basal ganglia, bilateral cerebellum, and right facial nerve nucleus were activated during both the observation/execution tasks. Group independent component analysis revealed that a functional network component involving the aforementioned regions were activated during both observation/execution tasks. The data suggest that the motor synchronization of emotional facial expressions involves a widespread observation/execution matching network encompassing the neocortex, limbic system, basal ganglia, cerebellum, and brainstem.

Model-Rebuilt Disturbance Observer of a Tracking System Based on Acceleration Fusion for Laser Power Transmission

When using laser energy to power long-distance and fast-moving targets, it requires a fast-response and high-precision acquisition, pointing and tracking (APT) system. A fast-steering mirror (FSM) system was used in this paper to track the solar cell array as laser power receiver. The disturbance suppression performance is a key indicator for the FSM stabilization. Generally, a fiber-optic gyroscope (FOG) is employed in the high-sampling-rate velocity loop to enhance the anti-interference ability. However, with the expansion of miniaturized applications, a relatively large, heavy, and high-power FOG is hard to be installed on the small mirror. With this case, this paper used a small-size and high-bandwidth MEMS linear accelerometer in the acceleration loop, substituting the gyroscope. However, the drift and high-frequency noise of the MEMS accelerometer in low frequency will cause APT disturbance. Therefore, an acceleration fusion method with a modified complementary filter was proposed to blend signals of the charge-coupled device and the accelerometers. The fused virtual acceleration can eliminate drift and reduce noise in low frequency and was eventually used in the model-rebuilt disturbance observer loop. At last, the measured results show that the disturbance suppression performance is improved using the presented method, and low-price and small-size MEMS accelerometer can be applied in the APT system.

Особенности реактивности μ-ритма ЭЭГ у детей с расстройствами аутистического спектра в ситуациях помогающего поведения

One of the subjects being discussed by the professional community currently is the role possibly played by the mirror neuron system (MNS) in the violation of social behavior of children with autism spectrum disorders (ASD). The MNS is known to shape the perception of emotions of others and understanding and imitation of their actions. Mu rhythm desynchronization in EEG is considered to be the indicator of the MNS activation. The purpose of this study was to identify the features of reactivity of the EEG mu rhythm within an individually determined frequency range in preschoolers with ASD in situations requiring instrumental, emotional and altruistic helping behavior (HB). The study involved children 4–7 years old with ASD (n = 26) and their normally developing peers without the condition (n = 37). Although in most cases, HB was more pronounced in the group of normally developing children, the differences between the groups are significant only for altruistic HP (p < 0.01), and for the situation requiring complex altruistic and emotional HP it approaches significance (p = 0.09). Evaluation of the mu rhythm reactivity indices showed that the tasks invoking complex altruistic and emotional HB bring this indicator down significantly in children with ASD compared to the group of normally developing participants, as shown by the central leads of the left and right hemispheres and the parietal lead of the right hemisphere (C3: p = 0.02 ; C4: p = 0.03; P4: p = 0.03). It is assumed that the detected features stem from the impaired functioning of the MNS and the downstream regulation to the MNS from prefrontal cortex and other areas of the neocortex. The data obtained can be used in development of EEG biofeedback training protocols for children with ASD.

ACTIVITY OF THE MIRROR NEURON SYSTEM IN PEOPLE WITH DEPRESSIVE SYMPTOMS

The global events of the last few years have led to the fact that more and more people are beginning to experience depressive symptoms. Developing depression significantly affects the emotional state of a person and his perception of the world around him. The purpose of this study was to analyze the reactions of mu- and alpha-rhythms reflecting the work of the mirror and visual systems of the brain, when perceiving and repeating emotionally colored social stimuli in people with different levels of depression. The study involved 32 healthy subjects who were divided into two groups – with high and low levels of depression on the Beck scale. A 32-channel EEG was recorded in two experimental blocks activating the emotional and motor components of the mirror neuron system (MNS): 1) when perceiving emotional faces expressing joy or grief; 2) when observing and repeating motor hand gestures. The desynchronization levels of the mu- and alpha-rhythm components in each of the tasks identified by the independent component method (ICA) were analyzed. It was found that the mu- desynchronization was significantly higher in people with depression when repeating motor hand movements, as well as when perceiving negative emotional facial expressions. Desynchronization of the alpha rhythm did not differ in the two groups of volunteers. Thus, the development of a depressive state increases MNS activation, and its sensitivity to negative emotional stimuli. This effect does not apply to the visual cortex and visual attention.

Effects of integrated action and sensory observation therapy based on mirror neuron and embodied cognition theory on upper limb sensorimotor function in chronic stroke: a study protocol for a randomised controlled trial

IntroductionThis study protocol aims to explore the effectiveness and neural mechanism of the integration of action observation therapy (AOT) and sensory observation therapy (SOT) for post-stroke patients on upper limb...

FORMATION OF PROSOCIAL BEHAVIOR AND ITS NEUROPHYSIOLOGICAL MECHANISMS IN EARLY CHILDHOOD

From a very early age children are capable on prosocial acts: giving objects, comforting and sharing with other people. This review considers modern research on the patterns and neurophysiological mechanisms of helping behavior (HB) formation in early childhood, including the results of the authors’ own work. Methods for HB researching in infants and young children are presented. The factors of development and neurophysiological mechanisms of instrumental, empathic and altruistic HB, and the role of empathy in these kinds of behaviors are analyzed. We also described data about involvement of various brain structures (for example, the mirror system as extended part of sensorimotor and emotional neural networks) in implementation of HB. The importance of research into the mechanisms of prosocial behavior for the full-fledged upbringing and education of children in the conditions of modern society is emphasized.

The effect of action observation combined with high-definition transcranial direct current stimulation on motor performance in healthy adults: A randomized controlled trial.

Action observation (AO) can improve motor performance in humans, probably via the human mirror neuron system. In addition, there is some evidence that transcranial direct current stimulation (tDCS) can improve motor performance. However, it is yet to be determined whether AO combined with tDCS has an enhanced effect on motor performance. We investigated the effect of AO combined with high-definition tDCS (HD-tDCS) targeting the inferior parietal lobe (IPL) and inferior frontal gyrus (IFG), the main aggregates of the human mirror neuron system, on motor performance in healthy adults and compared the immediate vs. 24-h retention test effects (anodal electrodes were placed over these regions of interest). Sixty participants were randomly divided into three groups that received one of the following single-session interventions: (1) observation of a video clip that presented reaching movement sequences toward five lighted units + active HD-tDCS stimulation (AO + active HD-tDCS group); (2) observation of a video clip that presented the same reaching movement sequences + sham HD-tDCS stimulation (AO + sham HD-tDCS group); and (3) observation of a video clip that presented neutral movie while receiving sham stimulation (NM + sham HD-tDCS group). Subjects' reaching performance was tested before and immediately after each intervention and following 24 h. Subjects performed reaching movements toward units that were activated in the same order as the observed sequence during pretest, posttest, and retest. Occasionally, the sequence order was changed by beginning the sequence unexpectedly with a different activated unit. Outcome measures included mean Reaching Time and difference between the Reaching Time of the unexpected and expected reaching movements (Delta). In the posttest and retest, Reaching Time and Delta improved in the AO + sham HD-tDCS group compared to the NM + HD-sham tDCS group. In addition, at posttest, Delta improved in the AO + active HD-tDCS group compared to the NM + sham HD-tDCS group. It appears that combining a montage of active HD-tDCS, which targets the IPL and IFG, with AO interferes with the positive effects of AO alone on the performance of reaching movement sequences.

To see is to experience: Aggression neurons light up when witnessing a fight

Fighting is an intense experience not only for the executors but also for the observers. In the current issue of Cell, Yang etal. identified hypothalamic aggression mirror neurons, activated during both physical fighting and witnessing a fight, possibly representing a neural mechanism for understanding social experiences in other minds.

Survey of Innovative Techniques for Speed Measurement of Vehicles

Advanced technology offers various alternatives for the speed measurement of vehicles. However, different technologies often result in different accuracy in the speed measurement of the vehicle. Lack of knowledge of accuracy between different technologies is a common problem for the researcher. This paper discusses the different techniques for speed measurement of vehicle-based on the theoretical study. One of the primary reasons for measuring speed is to enforce traffic speed laws and promote road safety. Speed limits are set to ensure that vehicles are travelling at safe speeds, given the conditions of the road, weather, and traffic. The use of speed measuring devices such as radar guns, laser guns, and speed cameras allows law enforcement agencies to monitor traffic and identify vehicles that are exceeding the speed limit. This information can then be used to issue citations or warnings to drivers, and ultimately to reduce the number of speed-related accidents and improve road safety. Various speed measurement techniques are included such as. RADAR (Radio Detection and Ranging) - this is one of the most common speed measurement techniques and uses radio waves to determine the speed of a vehicle, GPS (Global Positioning System) - GPS uses satellite technology to determine the location and speed of a vehicle. The MIRROR system uses multiple radar units to determine the speed of a vehicle, LIDAR (Light Detection and Ranging) - this technique gauges a vehicle's speed using lasers. The Speed Detection Camera System (SDCS) measures a vehicle's speed using cameras and image processing methods. On the highway, video streams are employed in image processing techniques to calculate the speed of the car.

Laboratory demonstration of the prediction of wind-blown turbulence by adaptive optics at 8 kHz with use of LQG control.

The low-latency adaptive optical mirror system (LLAMAS) is designed to push the limits on achievable latencies and frame rates. It has 21 subapertures across its pupil. A reformulated version of the linear quadratic Gaussian (LQG) method predictive Fourier control is implemented in LLAMAS; for all modes, it takes just 30µs to compute. In the testbed, a turbulator mixes hot and ambient air to produce wind-blown turbulence. Wind prediction clearly improves correction when compared to an integral controller. Closed-loop telemetry shows that wind-predictive LQG removes the characteristic "butterfly" and reduces temporal error power by up to a factor of three for mid-spatial frequency modes. Strehl changes seen in focal plane images are consistent with telemetry and the system error budget.

Compression of Few-Microjoule Femtosecond Pulses in a Hollow-Core Revolver Fiber

Gas-filled hollow-core fibers are a convenient tool for laser pulse compression down to a few-cycle duration. The development of compact, efficient and high quality compression schemes for laser pulses of relatively low μJ-level energies is of particular interest. In this work, temporal pulse compression based on nonlinear spectral broadening in a xenon-filled revolver fiber followed by a chirped mirror system is investigated. A 250 fs pulse at a central wavelength of 1.03 μm is compressed to 13.3 fs when the xenon pressure was tuned to provide zero group velocity dispersion near 1.03 μm. The energies of input and compressed pulses are 3.8 and 2.7 μJ, respectively. The compression quality factor of 1.8 is achieved.

Monte-Carlo estimation of geometric sensitivities in Solar Power Tower systems of flat mirrors

Optical optimizations for a Concentrated Solar Power (CSP) system are currently limited largely to gradient-free methods, since the gradient is hard to obtain by using the existing numerical optics tools available in the community. This article aims to build new algorithms of the Monte-Carlo type, which numerically estimate the gradient of power impacting the receiver with respect to the geometric parameters that characterize the geometric status of the heliostats in the heliostats field, for a Solar Power Tower (SPT) system.Physical models will be built for the specific intensity and also for its derivatives to the geometric parameters of the heliostats, also called geometric sensitivities of intensity. Similar to the intensity but with their own models, they are regarded as physical quantities emitted, absorbed and reflected in the system. They carry the perturbations of intensity as information, corresponding to the relations between the geometric parameters and the physical events in the SPT system: blocking, spillage, shadowing, etc. These relations will be distinguished and discussed.Finally, not only the gradient but also the contributions of physical events (blocking, spillage, shadowing, etc.) to the gradient can be estimated for further sensitivity analysis and optimization processes.