Mirror Neuron System Activity Research Articles

Feasibility of fNIRS in Children with Developmental Coordination Disorder

IntroductionBalance deficits are heterogeneous among children with Developmental Coordination Disorder (DCD). Balance performance depends on different balance domains, each associated with specific underlying neurological systems. In DCD, any of these domains can be affected, but the control mechanisms are poorly understood. The mirror neuron system (MNS) seems to play a key-role in DCD-related deficits. To understand the role of MNS as a control mechanism underlying the balance deficits, simultaneous registration of cortical MNS activity while performing balance tasks is imperative. Therefore, a protocol for combining real-time registration of cortical MNS activity during functional balance tasks in children with DCD, CP and TD is introduced. Methods: Children with DCD, CP and TD (n=108) aged 5-10yr perform preselected tasks of the Kids-BESTest, representing specific balance domains (mixed design): leaning with eyes closed (stability limits/verticality), single-leg-stance, alternate stair touching (anticipatory balance), in-place response, compensatory stepping backward (reactive balance) and walking over obstacles (gait stability). Simultaneously, functional Near-Infrared Spectroscopy (fNIRS) monitors cortical activity involving the MNS: premotor, inferior and superior parietal cortex and supplementary motor area. An 8-8-optode bundle, making 22 channels, targets this region of interest. Outcome measures are: (de)oxygenated hemoglobin concentration changes per task per channel. Results: In this ongoing research, the protocol was already feasible in 19 children (7.52±1.19). Conclusion: Simultaneous registration of cortical MNS activity (fNIRS) and Kids-BESTest scores will help increase the understanding of the control mechanisms underlying the heterogeneous balance problems in DCD. Consequently, first steps are made to confirm whether DCD shows deviant or delayed development.DisclosureNo significant relationships.

Is there a relationship between EEG and sTMS neurophysiological markers of the putative human mirror neuron system?

The mirror neuron system (MNS) has been theorized to play a neurobiological role in a number of social cognitive abilities and is commonly indexed putatively in humans via interpersonal motor resonance (IMR) and mu suppression. Although both indices are thought to measure similar neuronal populations (i.e., "mirror neurons"), it has been suggested that these methods are unrelated, and therefore, incompatible. However, prior studies reporting no relationships were typically conducted in small and underpowered samples. Thus, we aimed to investigate this potential association in a large sample of neurotypical adults (N=116; 72 females). Participants underwent transcranial magnetic stimulation (TMS), electromyography (EMG), and electroencephalography (EEG) during the observation of videos of actors performing grasping actions in order to index IMR and mu suppression (in beta, lower alpha, and upper alpha bandwidths). A series of linear regressions revealed no associations between IMR and each of the mu suppression bandwidths. Supplementary Bayesian analyses provided further evidence in favor of the null (B01 =8.85-8.93), providing further support for no association between the two indices of MNS activity. Our findings suggest that these two measures may indeed be unrelated indices that perhaps assess different neurophysiological aspects of the MNS. These results have important implications for future studies examining the MNS.

Altering Facial Movements Abolishes Neural Mirroring of Facial Expressions

People tend to automatically imitate others’ facial expressions of emotion. That reaction, termed “facial mimicry” has been linked to sensorimotor simulation—a process in which the observer’s brain recreates and mirrors the emotional experience of the other person, potentially enabling empathy and deep, motivated processing of social signals. However, the neural mechanisms that underlie sensorimotor simulation remain unclear. This study tests how interfering with facial mimicry by asking participants to hold a pen in their mouth influences the activity of the human mirror neuron system, indexed by the desynchronization of the EEG mu rhythm. This response arises from sensorimotor brain areas during observed and executed movements and has been linked with empathy. We recorded EEG during passive viewing of dynamic facial expressions of anger, fear, and happiness, as well as nonbiological moving objects. We examine mu desynchronization under conditions of free versus altered facial mimicry and show that desynchronization is present when adult participants can freely move but not when their facial movements are inhibited. Our findings highlight the importance of motor activity and facial expression in emotion communication. They also have important implications for behaviors that involve occupying or hiding the lower part of the face.

Observation, imaginary performance and actual performance of motor tasks in patients with temporal lobe epilepsy: An EEG study

Numerous studies indicate that during the observation and imaginary performance of movements, a decrease in the sensorimotor mu-rhythm in the central regions of the scalp reflects the degree of the mirror neuron system (MNS) activity, which ensures the perception of non-verbal signals during social interactions. Proof of the existence of the MNS in humans and subsequent invasive studies of its properties were carried out with the participation of patients with epilepsy, while the possible disruptions of the MNS in these patients were not taken into account. In this work, we analyzed the responses of the sensorimotor rhythm to the observation, imaginary performance and actual performance of various movements in patients with temporal lobe epilepsy and control group participants. It was found that mu-desynchronization is more pronounced in patients with epilepsy than in control group participants in the upper frequency (10.5 – 13 Hz) sub-band. Characteristic differences between the groups also emerged during tasks associated with movements that require two hands

Effects of perinatal dioxin exposure on mirror neuron activity in 9-year-old children living in a hot spot of dioxin contamination in Vietnam

BackgroundFor 8 years, we have followed up a birth cohort comprising 241 mother-and-infant pairs living around the Da Nang airbase, a hot spot of dioxin contamination in Vietnam, and have reported the impacts of perinatal dioxin exposure on the neurodevelopment of children at various ages. In the present study, 9 years after birth, we investigated the effects of perinatal dioxin exposure on mu and theta rhythms by analyzing EEG power during the execution and observation of hand movements, which indicate mirror neuron system activity. MethodsOne hundred fifty-five 9-year-old children (86 boys and 69 girls) from the Da Nang birth cohort participated in the EEG examination with free viewing of hand movements. The dioxin levels in their mothers’ breast milk, measured 1 month after birth, were used as perinatal dioxin exposure markers. A log transform of the ratio of EEG power during execution or observation of the hand movements relative to the power during observation of a bouncing ball for theta and mu rhythms was used to evaluate mirror neuron activity. ResultsIn both brain hemispheres, the log power ratio in the theta band was significantly higher (i.e., less reduction of power) during observation of hand movements in girls exposed to high levels of TCDD. In boys, however, dioxin congeners other than TCDD, including HxCDDs and several PCDF congeners, contributed to increased log power ratios in the theta band. Particularly for PCDF congeners, the log power ratios in the lowest group among 4 exposure groups were lowest and significantly increased (i.e., decreasing reduction of power) with increasing dose. ConclusionPerinatal TCDD exposure may influence the mirror neuron system of the brain, which plays an important role for social-emotional behavior in children, particularly in girls living in a hot spot of dioxin contamination in Vietnam.

The Relationship between Motor Coordination and Imitation: An fNIRS Study.

Although motor coordination and imitation are important factors affecting motor skill learning, few studies have examined the relationship between them in healthy adults. In order to address this in the present study, we used fNIRS to analyze the relationship between motor coordination and imitation in college students. Our results showed that: (1) motor coordination in female students was positively correlated with the average time taken to perform an imitation; (2) the mean imitation time was negatively correlated with the activation level of the supplementary motor cortex, primary somatosensory cortex, and angular gyrus of the mirror neuron system; (3) motor coordination in female students moderated mirror neuron system (MNS) activation and imitation. For women with low rather than high motor coordination, higher MNS activation was associated with a stronger imitation ability. These results demonstrate that motor coordination in female students is closely related to action imitation, and that it moderates the activation of the MNS, as measured via fNIRS.

Yoga therapy for social cognition in schizophrenia: An experimental medicine-based randomized controlled trial.

Negative symptoms and cognitive deficits are difficult-to-treat symptoms of schizophrenia. In this single blind randomized controlled study, we compared change in social cognitive performance in persons with Schizophrenia (PWS) (as per DSM-5), after 6 weeks of yoga intervention with a waitlist control group. We also examined changes in putative Mirror Neuron System (MNS) activity measured by Transcranial Magnetic Stimulation (TMS) in a subset of sample (n = 30). 51 PWS stabilized on antipsychotic medication for at least 6 weeks, were assigned to add-on yoga therapy (YT) (n = 26) or waitlist (WL) (n = 25). Subjects in the YT group received add-on yoga therapy (20 sessions in 6 weeks). Both the groups continued their standard treatment and were assessed at baseline and after 6 weeks for social cognition, clinical symptoms and social disability. RM-ANOVA showed significant interaction between time and group for social cognition composite score (SCCS) (F = 42.09 [1,44], P < 0.001); negative symptoms (SANS) (F = 74.91 [1,45], P < 0.001); positive symptoms (SAPS) (F = 16.05 [1,45], P < 0.001) and social disability (GSDS) (F = 29.91 [1,46], P < 0.001). MNS activity had increased after 6 weeks in both groups but not of statistical significance. This study demonstrates that 6 weeks of add-on yoga therapy could improve social cognition in PWS compared to waitlist control subjects. However, the change in social cognition was not associated with a change in the putative MNS-activity. It necessiatates further studies to investigate the mechanistic processes of yoga and replicate these observations in a larger sample.

EEG mu suppression which differentiates self from others are correlated with empathic abilities

Previous studies have indicated that the sense of the “self” is associated with specific brain regions and neural network activity. Moreover, it has been reported that the mirror neuron system, which functions when executing or observing actions, might contribute to differentiating self from others and forming the basis of the sense of self. However, little is known to date about how the mirror neuron system, which reacts to both self and others’ actions, contributes to differentiating oneself from others. This study examined the characteristics of self-oriented activity in mirror neuron system signals using stimuli facilitating self-discrimination from others. The EEG resulting from observing hand movements of the self and another person were examined from the first-person and the third-person perspectives. The results indicated that mu suppression, which is an index of mirror neuron system activity, increased for the self from the first-person perspective, suggesting that mu suppression might reflect the difference between self and others. Conversely, the mu suppression's variations in self-other orientation increased in the third-person perspective, suggesting that individual differences in response orientation might be correlated with empathetic perspective-taking skills.

Modulation of Interhemispheric Inhibition between Primary Motor Cortices Induced by Manual Motor Imitation: A Transcranial Magnetic Stimulation Study.

Imitation has been proven effective in motor development and neurorehabilitation. However, the relationship between imitation and interhemispheric inhibition (IHI) remains unclear. Transcranial magnetic stimulation (TMS) can be used to investigate IHI. In this study, the modification effects of IHI resulting from mirror neuron system (MNS) activation during different imitations are addressed. We measured IHI between homologous primary motor cortex (M1) by analyzing the ipsilateral silent period (iSP) evoked by single-pulse focal TMS during imitation and analyzed the respective IHI modulation during and after different patterns of imitation. Our main results showed that throughout anatomical imitation, significant time-course changes of iSP duration through the experiment were observed in both directions. iSP duration declined from the pre-imitation time point to the post-imitation time point and did not return to baseline after 30 min rest. We also observed significant iSP reduction from the right hemisphere to the left hemisphere during anatomical and specular imitation, compared with non-imitative movement. Our findings indicate that using anatomical imitation in action observation and execution therapy promotes functional recovery in neurorehabilitation by regulating IHI.

Brain activity of the emotional circuit in Parkinson’s disease patients with freezing of gait

ObjectiveEmotional processes might influence freezing of gait (FoG) in Parkinson’s disease (PD) patients. We assessed brain functional MRI (fMRI) activity during a “FoG-observation-task” in PD-FoG patients relative to healthy controls. MethodsTwenty-four PD-FoG patients and 18 age- and sex-matched healthy controls performed clinical and neuropsychological evaluations, and fMRI experiments including: i) “FoG-observation-task” consisting of watching a patient experiencing FoG during a walking task (usually evoking FoG); ii) “gait-observation-task” consisting of watching a healthy subject performing similar walking tasks without experiencing FoG. ResultsDuring both tasks, PD-FoG patients showed reduced activity of the fronto-parietal mirror neuron system (MNS) relative to controls. In the “FoG-observation-task” relative to the “gait-observation-task”, PD-FoG patients revealed an increased recruitment of the anterior medial prefrontal cortex and a reduced recruitment of the dorsomedial prefrontal cortex and hippocampus relative to controls. Healthy controls in the “FoG-observation-task” relative to the “gait-observation-task” showed increased recruitment of cognitive empathy areas and decreased activity of the fronto-parietal MNS. ConclusionOur results suggest that when PD-FoG patients observe a subject experiencing FoG, there is an increased activity of brain areas involved in self-reflection emotional processes and a reduced activity of areas related to motor programming, executive functions and cognitive empathy. These findings support previous evidence on the critical role of the emotional circuit in the mechanisms underlying FoG.

초등학생의 신체활동 수준에 따른 공감 능력의 차이 : 대뇌 거울 신경계 활성화에 관한 탐색적 연구

공감 능력 발달기에 있는 초등학생을 대상으로 신체활동 수준에 따라 상이하게 형성될 수 있는 신경심리학적 공감 능 력의 차이를 EEG 뮤 리듬을 통해 탐색적으로 알아보는 것이 연구의 주요 목적이다. 연구의 목적을 달성하기 위해 초 등학교 5, 6학년 남·여학생 22명을 대상으로 IPAQ 응답 결과를 바탕으로 중고강도 신체활동 집단(11명)과 통제집단 (11명)으로 구분하여 실험을 진행하였다. 실험과제는 공감 각성 과제로 모든 피험자는 고통 관련과 비고통 관련 공감 각성 과제를 각각 3분씩 실시하였다. 피험자가 과제를 실시하는 동안 뇌파를 측정하였고, 주요 측정영역은 감각운동 영역인 C3, Cz, C4였다. 자료분석은 Windows SPSS Ver. 26.0 프로그램을 이용하여 측정영역의 뮤 리듬에 대한 집 단(MVPA vs YK)과 조건(Pain vs No-pain) 간 일원분산분석을 각각 실시하였고, 자기보고식 척도인 공감지수와 뮤 리듬 활성화 간의 상관 정도를 알아보기 위해 상관관계 분석을 실시하여 결과를 도출하였다. 본 연구의 결과는 다음 과 같다. 첫째, 고통 관련 공감 각성 조건에서 중고강도 신체활동 집단이 통제집단보다 공감 능력을 반영하는 신경생 리학적 지표인 거울 신경 영역의 뮤 리듬 억제가 유의하게 높은 것으로 나타났다. 둘째, 공감 각성 조건과 관계없이 공감지수의 하위변인인 인지적 공감과 뮤 리듬 활성화 간의 유의한 정적 상관이 나타났다. 본 연구결과는 중고강도 신체활동 집단이 더욱 우수하고 효율적인 거울 신경 영역의 신경학적 네트워크를 가지고 있는 것을 의미하며, 나아가 초등학생의 친사회적 행동 형성에 긍정적인 영향을 미칠 수 있을 것으로 판단된다. 또한, 인지적 공감지수에 대한 주 관적인 평가가 실제 거울 신경계 활성화를 반영하거나 추정할 수 있는 수단이 될 수 있을 것으로 예측된다.

Differential mirror neuron system (MNS) activation during action observation with and without social-emotional components in autism: a meta-analysis of neuroimaging studies

BackgroundImpaired imitation has been found to be an important factor contributing to social communication deficits in individuals with autism spectrum disorder (ASD). It has been hypothesized that the neural correlate of imitation, the mirror neuron system (MNS), is dysfunctional in ASD, resulting in imitation impairment as one of the key behavioral manifestations in ASD. Previous MNS studies produced inconsistent results, leaving the debate of whether “broken” mirror neurons in ASD are unresolved.MethodsThis meta-analysis aimed to explore the differences in MNS activation patterns between typically developing (TD) and ASD individuals when they observe biological motions with or without social-emotional components. Effect size signed differential mapping (ES-SDM) was adopted to synthesize the available fMRI data.ResultsES-SDM analysis revealed hyperactivation in the right inferior frontal gyrus and left supplementary motor area in ASD during observation of biological motions. Subgroup analysis of experiments involving the observation of stimuli with or without emotional component revealed hyperactivation in the left inferior parietal lobule and left supplementary motor during action observation without emotional components, whereas hyperactivation of the right inferior frontal gyrus was found during action observation with emotional components in ASD. Subgroup analyses of age showed hyperactivation of the bilateral inferior frontal gyrus in ASD adolescents, while hyperactivation in the right inferior frontal gyrus was noted in ASD adults. Meta-regression within ASD individuals indicated that the right cerebellum crus I activation increased with age, while the left inferior temporal gyrus activation decreased with age.LimitationsThis meta-analysis is limited in its generalization of the findings to individuals with ASD by the restricted age range, heterogeneous study sample, and the large within-group variation in MNS activation patterns during object observation. Furthermore, we only included action observation studies which might limit the generalization of our results to the imitation deficits in ASD. In addition, the relatively small sample size for individual studies might also potentially overestimate the effect sizes.ConclusionThe MNS is impaired in ASD. The abnormal activation patterns were found to be modulated by the nature of stimuli and age, which might explain the contradictory results from earlier studies on the “broken mirror neuron” debate.

Сенсомоторные ритмы ЭЭГ у детей с расстройствами аутистического спектра

One of the currently assumed causes of impaired social interaction exhibited by children with autism spectrum disorders (ASD) is dysfunction of the mirror neuron system (MNS), which is responsible for imitation, understanding the intentions and emotions of other people. Desynchronization of sensorimotor rhythms is considered to be the indicator of MNS activation. This study aimed to analyze the specific patterns of reactivity of the μ-rhythm in an individually determined frequency range and β-rhythm on the EEG in children with ASD during independent movements, observation, imitation and auditory perception of similar movements performed by another person. The data collected were compared to those describing normally developing children. The study involved right-handed children with ASD aged 5–10 (n = 10) and normally developing children (n = 10). In the independent movements exercise, β-rhythm desynchronization was more pronounced in children with ASD, with difference becoming significant in the P4 locus (p = 0.03). In the movements imitation exercise, the groups showed significant differences in the EEG μ-rhythm in the locus C3 (p = 0.03). Auditory perception of movements revealed significant differences in the ranges of both μ-rhythm (loci F3 and Fz (p = 0.02), F4 (p = 0.04), Cz (p = 0.009)) and β-rhythm (loci Fz (p = 0.01), F4 (p = 0.02)). In these situations, children with ASD exhibited synchronization of sensorimotor rhythms, while normally developing children showed desynchronization. The assumption is that the specific patterns revealed are the consequences of disruption of functions of MNS and anti-mirror system. The data obtained can be used in development of EEG biofeedback training protocols for children with ASD.

Is the Putative Mirror Neuron System Associated with Empathy? A Systematic Review and Meta-Analysis.

Theoretical perspectives suggest that the mirror neuron system (MNS) is an important neurobiological contributor to empathy, yet empirical support is mixed. Here, we adopt a summary model for empathy, consisting of motor, emotional, and cognitive components of empathy. This review provides an overview of existing empirical studies investigating the relationship between putative MNS activity and empathy in healthy populations. 52 studies were identified that investigated the association between the MNS and at least one domain of empathy, representing data from 1044 participants. Our results suggest that emotional and cognitive empathy are moderately correlated with MNS activity, however, these domains were mixed and varied across techniques used to acquire MNS activity (TMS, EEG, and fMRI). Few studies investigated motor empathy, and of those, no significant relationships were revealed. Overall, results provide preliminary evidence for a relationship between MNS activity and empathy. However, our findings highlight methodological variability in study design as an important factor in understanding this relationship. We discuss limitations regarding these methodological variations and important implications for clinical and community translations, as well as suggestions for future research.

Effect of Acute Moderate-Intensity Exercise on the Mirror Neuron System: Role of Cardiovascular Fitness Level.

ObjectivesThe aims of this study were to use functional near-infrared spectroscopy (fNIRS) to determine whether cardiovascular fitness levels modulate the activation of the mirror neuron system (MNS) under table-setting tasks in non-exercise situation, to replicate the study that positive effect of acute moderate-intensity exercise on the MNS and investigate whether cardiovascular fitness levels modulates the effect of exercise on the activation of the MNS.MethodsThirty-six healthy college-aged participants completed a maximal graded exercise test (GXT) and were categorized as high, moderate, or low cardiovascular fitness. Participants then performed table-setting tasks including an action execution task (EXEC) and action observation task (OBS) prior to (PRE) and after (POST) either a rest condition (CTRL) or a cycling exercise condition (EXP). The EXP condition consisted of a 5-min warm-up, 15-min moderate-intensity exercise (65% VO2max), and 5-min cool-down.ResultsNo significant differences were observed for Oxy-Hb and Deoxy-Hb between different cardiovascular fitness levels in the EXEC or OBS tasks in the non-exercise session. But there were significant improvements of oxygenated hemoglobin (Oxy-Hb) in the inferior frontal gyrus (IFG) and pre-motor area (PMC) regions under the OBS task following the acute moderate exercise. Particularly, the improvements (Post-Pre) of Δ Oxy-Hb were mainly observed in high and low fitness individuals. There was also a significant improvement of deoxygenated hemoglobin (Deoxy-Hb) in the IPL region under the OBS task. The following analysis indicated that exercise improved Δ Deoxy-Hb in high fitness individuals.ConclusionThis study indicated that the activation of MNS was not modulated by the cardiovascular fitness levels in the non-exercise situation. We replicated the previous study that moderate exercise improved activation of MNS; we also provided the first empirical evidence that moderate-intensity exercise positively affects the MNS activation in college students of high and low cardiovascular fitness levels.

Emotion specific neural activation for the production and perception of facial expressions

The distinction between different facial emotions is crucial for interpersonal communication. Shared neural circuits for facial emotion production and perception are considered to facilitate the ability to understand other's emotional state via mirror neuron mechanisms. Little is known about how diverse emotions differentially activate the Mirror Neuron System (MNS) during facial expression processing. In a functional magnetic resonance imaging (fMRI) task, 178 healthy subjects perceived and produced emotional (happy vs angry) and non-emotional (lip-protrusion vs no movement) facial expressions. Dynamic facial expressions were displayed as 5 sec video clips. We identified three overlapping networks of neural activation for happy, angry, and non-emotional (lip-protrusion) facial expression production and perception. Importantly, this overlap was largely due to the common motor component of facial expressions. However, for happy facial expressions, we found specific MNS activation in the right temporal pole. For angry facial expressions we found such activation in the left inferior frontal gyrus, pars orbitalis, and the cerebellum (lobules VII and VIII). We extend knowledge on mirror neuron mechanisms as our results provide evidence for emotion specific shared neural activation for the production and perception of facial emotions. This emotion specific representation of other's emotion in one's own neural production system might facilitate understanding of other's mental or emotional states.

Sensorimotor cortex activation during anticipation of upcoming predictable but not unpredictable actions

ABSTRACTThe mirror neuron system (MNS) becomes active during action execution and action observation, which is presumably reflected by reductions in mu (8–13 Hz) activity in the electroencephalogram over the sensorimotor cortex. The function of the MNS is still fiercely debated. The current study aimed to investigate a role of the MNS in anticipating others’ actions by examining whether the MNS was activated – indexed by mu power suppression – prior to the onset of observed actions when the onset and type of action could be predicted on the basis of environmental cues. Young adults performed and observed cued grasping and placing actions in a card game in a real-life setting, while the predictability of the observed actions was manipulated using rules. Significant mu suppression, relative to within-trial baseline activity, was found both prior to and during executed actions, but also during action observation, and, crucially, prior to observed actions provided they were predictable. No anticipatory mu reductions were found prior to unpredictable observed actions. These results suggest top-down modulation of MNS activity by conceptual knowledge. This is the first study to demonstrate mu suppression prior to action onset – possibly reflecting MNS anticipatory activity – by explicitly manipulating predictability.

Activation of Mirror Neuron Regions Is Altered in Developmental Coordination Disorder (DCD)-Neurophysiological Evidence Using an Action Observation Paradigm.

Children with Developmental Coordination Disorder (DCD) have difficulty performing and learning motor skills. Automatic activation of the mirror neuron system (MNS) during action observation and its coupling to the motor output system are important neurophysiological processes that underpin observational motor learning. In the present study, we tested the hypothesis that MNS function is disrupted in children with DCD by using sensitive electroencephalography (EEG)-based measures of MNS activation during action observation. Specifically, we predicted reduced mu-suppression and coherence in DCD compared with typically developing children. Neural activation of the motor network was measured by EEG, specifically event-related desynchronization (ERD) of mu rhythms and fronto-parietal coherence. Children (15 DCD/15 controls) were tested under two task conditions: observational learning (imitation of an observed action) and detection (report a deviant movement after observation). EEG-metrics were compared between groups using linear mixed-effects models. As predicted, children with DCD showed lower levels of mu suppression and reduced modulation of coherence during the observational learning task compared with their non-DCD peers. Notably, mu suppression was reduced in DCD over the entire imitation task (repetitions, and both observation and pause intervals). Action observation can be used for the acquisition of new motor skills. This form of learning entails the transposition of the observed action to the existing internal representations of the observer’s own motor system. The present neurophysiological results suggest that this process of learning is impaired in children with DCD. The results are discussed in relation to current hypotheses on mechanisms of DCD.

Exploring the EEG mu rhythm associated with observation and execution of a goal-directed action in 14-month-old preterm infants

Electroencephalographic mu rhythm desynchronization is thought to reflect Mirror Neuron System (MNS) activity and represents an important neural correlate of the coupling between action execution and perception. It is still unclear if the MNS in human ontogeny is already available at the beginning of postnatal life and how early experience impacts its development. Premature birth provides a “natural condition” for investigating the effects of early, atypical extra-uterine experience on MNS. The main aim of the present study was to investigate whether the MNS activity is associated with prematurity. We compared the mu rhythm activity in preterm (PT) and full-term (FT) 14-month old infants during an action observation/execution (AO/AE) task. Mu rhythm desynchronization was computed over frontal, central, parietal and occipital regions. Both groups showed mu rhythm suppression in all the scalp regions during action execution. Different desynchronization patterns emerged during action observation. Specifically, FT infants showed mu suppression in the right frontal, bilateral parietal and occipital regions; whereas PT infants exhibited mu suppression only in the right parietal region. Overall, these preliminary findings indicate that an atypical extra uterine experience might have an impact on the MNS activity.

Mirror Neuron System Activation in Children With Unilateral Cerebral Palsy During Observation of Actions Performed by a Pathological Model

Background. Recent evidence suggested that Action Observation Therapy (AOT), based on observation of actions followed by immediate reproduction, could be a useful rehabilitative strategy for promoting functional recovery of children affected by unilateral cerebral palsy (UCP). AOT most likely exploits properties of the parieto-premotor mirror neuron system (MNS). This is more intensely activated when participants observe actions belonging to their own motor repertoire. Objective. The aim of the present study was to investigate the issue of whether MNS of UCP children is better activated by actions performed by a paretic hand rather than a healthy one. Methods. Using functional magnetic resonance imaging, we assessed brain activation in a homogeneous group of 10 right UCP children compared with that of 10 right-handed typically developing (TD) children, during observation of grasping actions performed by a healthy or a paretic hand. Results. The results revealed a significant activation within the MNS in both UCP and TD children, more lateralized to the left hemisphere in the TD group. Most important, region of interest (ROI) analysis on parietal and premotor regions showed that, in UCP, the MNS was more strongly activated by observation of actions performed by the paretic hand, a motor model more similar to the observer’s motor repertoire. Conclusions. This study shows that children affected by spastic UCP exhibit enhanced activation of the MNS during observation of goal-directed actions performed by a pathological model with respect to a healthy one.