Action, observation or imitation of virtual hand movement affect differently regions of the mirror neuron system and the default mode network

Efficacy of Sensor-Based Training Using Exergaming or Virtual Reality in Patients with Chronic Low Back Pain: A Systematic Review

In its chronic and non-specific form, low back pain is experienced by a large percentage of the population; its persistence impacts the quality of life and increases costs to the health care system. In recent years, the scientific literature highlights how treatment based on assessment and functional recovery is effective through IMU technology with biofeedback or exergaming as part of the tools available to assist the evaluation and treatment of these patients, who present not only with symptoms affecting the lumbar spine but often also incorrect postural attitudes. Aim: Evaluate the impact of technology, based on inertial sensors with biofeedback or exergaming, in patients with chronic non-specific low back pain. A systematic review of clinical studies obtained from PubMed, Scopus, Science Direct, and Web of Science databases from 1 January 2016 to 1 July 2024 was conducted, developing the search string based on keywords and combinations of terms with Boolean AND/OR operators; on the retrieved articles were applied inclusion and exclusion criteria. The procedure of publication selection will be represented with the PRISMA diagram, the risk of bias through the RoB scale 2, and methodological validity with the PEDro scale. Eleven articles were included, all RCTs, and most of the publications use technology with exergaming within about 1-2 months. Of the outcomes measured, improvements were reported in pain, disability, and increased function; the neuropsychological sphere related to experiencing the pathology underwent improvements. From the results obtained, the efficacy of using technology based on exergames and inertial sensors, in patients with chronic non-specific low back pain, was increased. Further clinical studies are required to achieve more uniformity in the proposed treatment to create a common guideline for health care providers.

Distinct and additive effects of visual and vibratory feedback for motor rehabilitation: an EEG study in healthy subjects

INTRODUCTION

The use of visual and proprioceptive feedback is a key property of motor rehabilitation techniques. This feedback can be used alone, for example, for vision in mirror or video therapy, for proprioception in focal tendon vibration therapy, or in combination, for example, in robot-assisted training. This Electroencephalographic (EEG) study in healthy subjects explored the distinct neurophysiological impact of adding visual (video therapy), proprioceptive (focal tendinous vibration), or combined feedback (video therapy and focal tendinous vibration) to a motor imagery task.

METHODS

Sixteen healthy volunteers performed 20 mental imagery (MI) tasks involving right wrist extension and flexion under four conditions: MI alone (IA), MI + video feedback observation (IO), MI + vibratory feedback (IV), and MI + observation + vibratory feedback (IOV). Brain activity was monitored with EEG, and time-frequency neurophysiological markers of movement were computed. The emotions of the patients were also measured during the task.

RESULTS

In the alpha band, we observed bilateral ERD in the visual feedback conditions (IO, IOV). In the beta band, the ERD was bilateral in the IA, IV and IOV but more lateralized in the IV and IOV. After movement, we observed strong ERS in the IO and IOV but not in the IA or IV. Embodiment was stronger in conditions with vibratory feedback (IOV > IV > IA and IO) CONCLUSION: Conditions with visual feedback (IO, IOV) recruit the mirror neurons system (alpha ERD) and provide more accurate feedback of the task than IA and IV, which triggers motor validation pathways (beta rebound analysis). Vibratory feedback enhances the recruitment of the left sensorimotor areas, with a synergistic effect in the IOV (beta ERD analysis), thus maximizing embodiment. Visual and vibratory feedback recruits the sensorimotor cortex during motor imagery in different ways and can be combined to maximize the benefits of both techniques TRIAL REGISTRATION: https://clinicaltrials.gov/study/NCT04449328 .

Hands off, brain off? A meta-analysis of neuroimaging data during active and passive driving

BACKGROUND

Car driving is more and more automated, to such an extent that driving without active steering control is becoming a reality. Although active driving requires the use of visual information to guide actions (i.e., steering the vehicle), passive driving only requires looking at the driving scene without any need to act (i.e., the human is passively driven).

MATERIALS & METHODS

After a careful search of the scientific literature, 11 different studies, providing 17 contrasts, were used to run a comprehensive meta-analysis contrasting active driving with passive driving.

RESULTS

Two brain regions were recruited more consistently for active driving compared to passive driving, the left precentral gyrus (BA3 and BA4) and the left postcentral gyrus (BA4 and BA3/40), whereas a set of brain regions was recruited more consistently in passive driving compared to active driving: the left middle frontal gyrus (BA6), the right anterior lobe and the left posterior lobe of the cerebellum, the right sub-lobar thalamus, the right anterior prefrontal cortex (BA10), the right inferior occipital gyrus (BA17/18/19), the right inferior temporal gyrus (BA37), and the left cuneus (BA17).

DISCUSSION

From a theoretical perspective, these findings support the idea that the output requirement of the visual scanning process engaged for the same activity can trigger different cerebral pathways, associated with different cognitive processes. A dorsal stream dominance was found during active driving, whereas a ventral stream dominance was obtained during passive driving. From a practical perspective, and contrary to the dominant position in the Human Factors community, our findings support the idea that a transition from passive to active driving would remain challenging as passive and active driving engage distinct neural networks.

Mapping relational links between motor imagery, action observation, action-related language, and action execution

Actions can be physically executed, observed, imagined, or simply thought about. Unifying mental processes, such as simulation, emulation, or predictive processing, are thought to underlie different action types, whether they are mental states, as in the case of motor imagery and action observation, or involve physical execution. While overlapping brain activity is typically observed across different actions which indicates commonalities, research interest is also concerned with investigating the distinct functional components of these action types. Unfortunately, untangling subtleties associated with the neurocognitive bases of different action types is a complex endeavour due to the high dimensional nature of their neural substrate (e.g., any action process is likely to activate multiple brain regions thereby having multiple dimensions to consider when comparing across them). This has impeded progress in action-related theorising and application. The present study addresses this challenge by using the novel approach of multidimensional modeling to reduce the high-dimensional neural substrate of four action-related behaviours (motor imagery, action observation, action-related language, and action execution), find the least number of dimensions that distinguish or relate these action types, and characterise their neurocognitive relational links. Data for the model comprised brain activations for action types from whole-brain analyses reported in 53 published articles. Eighty-two dimensions (i.e., 82 brain regions) for the action types were reduced to a three-dimensional model, that mapped action types in ordination space where the greater the distance between the action types, the more dissimilar they are. A series of one-way ANOVAs and post-hoc comparisons performed on the mean coordinates for each action type in the model showed that across all action types, action execution and concurrent action observation (AO)-motor imagery (MI) were most neurocognitively similar, while action execution and AO were most dissimilar. Most action types were similar on at least one neurocognitive dimension, the exception to this being action-related language. The import of the findings are discussed in terms of future research and implications for application.

The acute effects of action observation training on upper extremity functions, cognitive processes and reaction times: a randomized controlled trial

Aim: To investigate the acute effects of action observation training on upper extremity functions, cognitive functions and response time in healthy, young adults. Materials & methods: A total of 60 participants were randomly divided into five groups: the self-action observation group, action observation group, action practice group, non-action observation group and control group. The Jebsen-Taylor hand function test (JTHFT), nine-hole peg test, serial reaction time task and d2 test of attention were applied to the participants before and after the interventions. Results: JTHFT performance with both non-dominant and dominant hands improved significantly compared with baseline in all groups (p < 0.001). JTHFT performance with non-dominant and dominant hands differed between the groups (p < 0.001). Conclusion: Action observation training seems to enhance the performance of upper extremity-related functions. Observing self-actions resulted in statistically significant positive changes in more variables compared with other methods. However, its clinical effectiveness over the other methods should be investigated in future long-term studies. Clinical Trial Registration: NCT04932057 (ClinicalTrials.gov).

In search of a naturalistic neuroimaging approach: Exploration of general feasibility through the case of VR-fMRI and application in the domain of episodic memory

Virtual Reality (VR) is an increasingly widespread tool for research as it allows the creation of experiments taking place in multimodal and daily-life-like environments, while keeping a strong experimental control. Adding neuroimaging to VR leads to a better understanding of the underlying brain networks activated during a naturalistic task, whether for research purposes or rehabilitation. The present paper focuses on the specific use of concurrent VR and fMRI and its technical challenges and feasibility, with a brief examination of the general existing solutions. Following the PRISMA guidelines, the review investigates the particular case of how VR-fMRI has explored episodic memory so far, with a comparison of object- and place-based episodic memory. This review confirms the involvement of cerebral regions well-known to be implicated in episodic memory and unravels other regions devoted to bodily and narrative aspects of the self, promoting new avenues of research in the domain of naturalistic episodic memory. Future studies should develop more immersive and interactive virtual neuroimaging features to increase ecological and embodied neurocognition aspects.

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

BACKGROUND

For 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.

METHODS

One 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.

RESULTS

In 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.

CONCLUSION

Perinatal 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.

Beyond motor recovery after stroke: The role of hand robotic rehabilitation plus virtual reality in improving cognitive function

Robot-assisted hand training adopting end-effector devices results in an additional reduction of motor impairment in comparison to usual care alone in different stages of stroke recovery. These devices often allow the patient to perform practical, attentive, and visual-spatial tasks in a semi-virtual reality (VR) setting. We aimed to investigate whether the hand end-effector robotic device Amadeo^TM could improve cognitive performance, beyond the motor deficit, as compared to the same amount of occupational treatment focused on the hand. Forty-eight patients (aged 54.3 ± 10.5 years, 62.5% female) affected by either ischemic or hemorrhagic stroke in the chronic phase were enrolled in the study. The experimental group (EG) underwent Amadeo^TM robotic training, while the control group (CG) performed occupational therapy involving the upper limb. Patients were assessed at the beginning and at the end of the rehabilitation protocol using a specific neuropsychological battery, as well as motor function tests. The EG showed greater improvements in different cognitive domains, including attentive abilities and executive functions, as well as in hand motor function, as compared to CG. Our study showed that task-oriented VR-based robotic rehabilitation enhanced not only motor function in the paretic arm but also global and specific cognitive abilities in post-stroke patients. We may argue that the hand robotic plus VR-based training may provide patients with an integration of cognitive and motor skill rehabilitation, thus amplifying the functional outcome achievement.

The Challenges and Perspectives of the Integration Between Virtual and Augmented Reality and Manual Therapies

Virtual reality (VR) and augmented reality (AR) have been combined with physical rehabilitation and psychological treatments to improve patients' emotional reactions, body image, and physical function. Nonetheless, no detailed investigation assessed the relationship between VR or AR manual therapies (MTs), which are touch-based approaches that involve the manipulation of tissues for relieving pain and improving balance, postural stability and well-being in several pathological conditions. The present review attempts to explore whether and how VR and AR might be integrated with MTs to improve patient care, with particular attention to balance and to fields like chronic pain that need an approach that engages both mind and body. MTs rely essentially on touch to induce tactile, proprioceptive, and interoceptive stimulations, whereas VR and AR rely mainly on visual, auditory, and proprioceptive stimulations. MTs might increase patients' overall immersion in the virtual experience by inducing parasympathetic tone and relaxing the mind, thus enhancing VR and AR effects. VR and AR could help manual therapists overcome patients' negative beliefs about pain, address pain-related emotional issues, and educate them about functional posture and movements. VR and AR could also engage and change the sensorimotor neural maps that the brain uses to cope with environmental stressors. Hence, combining MTs with VR and AR could define a whole mind-body intervention that uses psychological, interoceptive, and exteroceptive stimulations for rebalancing sensorimotor integration, distorted perceptions, including visual, and body images. Regarding the technology needed to integrate VR and AR with MTs, head-mounted displays could be the most suitable devices due to being low-cost, also allowing patients to follow VR therapy at home. There is enough evidence to argue that integrating MTs with VR and AR could help manual therapists offer patients better and comprehensive treatments. However, therapists need valid tools to identify which patients would benefit from VR and AR to avoid potential adverse effects, and both therapists and patients have to be involved in the development of VR and AR applications to define truly patient-centered therapies. Furthermore, future studies should assess whether the integration between MTs and VR or AR is practically feasible, safe, and clinically useful.

Effect of Traditional plus Virtual Reality Rehabilitation on Prognosis of Stroke Survivors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Virtual reality (VR) technology has begun to be gradually applied to clinical stroke rehabilitation. The study aims to evaluate the effect of traditional plus VR rehabilitation on motor function recovery, balance, and activities of daily living in stroke patients.

METHOD

Studies published in English prior to October 2020 were retrieved from PubMed, EMBASE, Web of Science, and the Cochrane Library. and used RevMan 5.3 software for meta-analysis.

RESULT

A total of 21 randomized controlled trials (RCTs) were included, which enrolled 619 patients. Traditional plus VR rehabilitation is better than traditional rehabilitation in upper limb motor function recovery measured by Fugl-Meyer Assessment-Upper Extremity (mean difference [MD] 3.49; 95% CI [1.24, 5.73]; P=.002) and manual dexterity assessed by Box & Block Test (MD 6.59; 95% CI [3.45, 9.74]; P<.0001); However, there is no significant difference from traditional rehabilitation in activities of daily living assessed by Functional Independence Measure (MD 0.38; 95% CI [-0.26, 1.02]; P=.25) and balance assessed by Berg Balance Scale (MD 2.18; 95% CI [-0.35, 4.71]; P=.09).

CONCLUSION

Traditional plus VR rehabilitation therapy is an effective method to improve the upper limb motor function and manual dexterity of patients with limb disorders after stroke, and immersive VR rehabilitation treatment may become a new option for rehabilitation after stroke.

Differences in cortical activation patterns during action observation, action execution, and interpersonal synchrony between children with or without autism spectrum disorder (ASD): An fNIRS pilot study

Engaging in socially embedded actions such as imitation and interpersonal synchrony facilitates relationships with peers and caregivers. Imitation and interpersonal synchrony impairments of children with Autism Spectrum Disorder (ASD) might contribute to their difficulties in connecting and learning from others. Previous fMRI studies investigated cortical activation in children with ASD during finger/hand movement imitation; however, we do not know whether these findings generalize to naturalistic face-to-face imitation/interpersonal synchrony tasks. Using functional near infrared spectroscopy (fNIRS), the current study assessed the cortical activation of children with and without ASD during a face-to-face interpersonal synchrony task. Fourteen children with ASD and 17 typically developing (TD) children completed three conditions: a) Watch-observed an adult clean up blocks; b) Do-cleaned up the blocks on their own; and c) Together-synchronized their block clean up actions to that of an adult. Children with ASD showed lower spatial and temporal synchrony accuracies but intact motor accuracy during the Together/interpersonal synchrony condition. In terms of cortical activation, children with ASD had hypoactivation in the middle and inferior frontal gyri (MIFG) as well as middle and superior temporal gyri (MSTG) while showing hyperactivation in the inferior parietal cortices/lobule (IPL) compared to the TD children. During the Together condition, the TD children showed bilaterally symmetrical activation whereas children with ASD showed more left-lateralized activation over MIFG and right-lateralized activation over MSTG. Additionally, using ADOS scores, in children with ASD greater social affect impairment was associated with lower activation in the left MIFG and more repetitive behavior impairment was associated with greater activation over bilateral MSTG. In children with ASD better communication performance on the VABS was associated with greater MIFG and/or MSTG activation. We identified objective neural biomarkers that could be utilized as outcome predictors or treatment response indicators in future intervention studies.

Cross-Modal Functional Connectivity of the Premotor Cortex Reflects Residual Motor Output After Stroke

Stroke is known to cause widespread activation and connectivity changes resulting in different levels of functional impairment. Recovery of motor functions is thought to rely mainly on reorganizations within the sensorimotor cortex, but increasing attention is being paid to other cerebral regions. To investigate the motor task-related functional connectivity (FC) of the ipsilesional premotor cortex (PMC) and its relation to residual motor output after stroke in a population of mostly poorly recoverd patients. Twenty-four stroke patients (23 right handed, mean age = 52.4 ± 12.6 years) with varying levels of motor deficits underwent functional magnetic resonance imaging while performing different motor tasks (passive mobilization, motor execution, and motor imagery of an extension movement of the unaffected hand [UH] or affected hand [AH]). For the different motor tasks, analyses of cerebral activation and task-related FC of the ipsilesional lateral sensorimotor network (SMN), and particularly the premotor cortex (PMC), were performed. Compared with UH data, FC of the ipsilesional lateral SMN during the passive or active motor tasks involving the AH was decreased with regions of the ipsilesional SMN and was increased with regions of the bilateral frontal and the ipsilesional posterior parietal cortices such as the precuneus (Pcu). During passive wrist mobilization, FC between the ipsilesional PMC and the contralesional SMN was negatively correlated with residual motor function, whereas that with nonmotor regions such as the bilateral Pcu and the contralesional dorsolateral prefrontal cortex was positively correlated with the residual motor function. Cross-modal FC of the ipsilesional PMC may reflect compensation strategies after stroke. The results emphasize the importance of the PMC and other nonmotor regions as prominent nodes involved in reorganization processes after a stroke.

Developmental Differences in Cortical Activation During Action Observation, Action Execution and Interpersonal Synchrony: An fNIRS Study

Interpersonal synchrony (IPS) is an important everyday behavior influencing social cognitive development; however, few studies have investigated the developmental differences and underlying neural mechanisms of IPS. functional near-infrared spectroscopy (fNIRS) is a novel neuroimaging tool that allows the study of cortical activation in the presence of natural movements. Using fNIRS, we compared cortical activation patterns between children and adults during action observation, execution, and IPS. Seventeen school-age children and 15 adults completed a reach to cleanup task while we obtained cortical activation data from bilateral inferior frontal gyrus (IFG), superior temporal sulcus (STS), and inferior parietal lobes (IPL). Children showed lower spatial and temporal accuracy during IPS compared to adults (i.e., spatial synchrony scores (Mean ± SE) in children: 2.67 ± 0.08 and adults: 2.85 ± 0.06; temporal synchrony scores (Mean ± SE) in children: 2.74 ± 0.06 and adults: 2.88 ± 0.05). For both groups, the STS regions were more activated during action observation, while the IFG and STS were more activated during action execution and IPS. The IPS condition involved more right-sided activation compared to action execution suggesting that IPS is a higher-order process involving more bilateral cortical activation. In addition, adults showed more left lateralization compared to the children during movement conditions (execution and IPS); which indicated greater inhibition of ipsilateral cortices in the adults compared to children. These findings provide a neuroimaging framework to study imitation and IPS impairments in special populations such as children with Autism Spectrum Disorder.

Is it necessary to show virtual limbs in action observation neurorehabilitation systems?

Introduction

Action observation neurorehabilitation systems are usually based on the observation of a virtual limb performing different kinds of actions. In this way, the activity in the frontoparietal Mirror Neuron System is enhanced, which can be helpful to rehabilitate stroke patients. However, the presence of limbs in such systems might not be necessary to produce mirror activity, for example, frontoparietal mirror activity can be produced just by the observation of virtual tool movements. The objective of this work was to explore to what point the presence of a virtual limb impacts the Mirror Neuron System activity in neurorehabilitation systems.

Methods

The study was conducted by using an action observation neurorehabilitation task during a functional magnetic resonance imaging (fMRI) experiment with healthy volunteers and comparing two action observation conditions that: 1 – included or 2 – did not include a virtual limb.

Results

It was found that activity in the Mirror Neuron System was similar during both conditions (i.e. virtual limb present or absent).

Conclusions

These results open up the possibility of using new tasks that do not include virtual limbs in action observation neurorehabilitation environments, which can give more freedom to develop such systems.