Neural representations involved in observed, imagined, and imitated actions are dissociable and hierarchically organized

Effectiveness of synchronous action observation and mental practice on upper extremity motor recovery after stroke

The purpose of this quasi-experimental pretest-posttest control group study was to examine the effect of group synchronous action observation/mental practice intervention compared to usual rehabilitation care on upper extremity motor recovery after stroke. The intervention group (n = 25) received usual care, consisting of a minimum of 3 hours of rehabilitation services per day, 5 days a week, plus group synchronous action observation/mental practice sessions 3 times per week and the control group (n = 26) received usual care. Outcome measures included the Kinesthetic and Visual Imagery Questionnaire Short Version (KVIQ-10), the Fugl-Meyer Assessment (FMA-UE) of affected upper extremity motor function only and The Box and Block Test (BBT). Although there were no statistically significant differences in upper extremity motor function between the two groups, a subgroup analysis of the intervention group identified statistically significant (FMA-UE: p < .001; BBT: p = .04) and Minimally Important Clinical Differences on upper extremity motor recovery between patients with behaviors demonstrating more versus less commitment to the intervention. Group synchronous action observation/mental practice is a promising intervention for patients demonstrating commitment to actively participating in the intervention to improve outcomes on upper extremity motor recovery after stroke.

Effect of Object on Kinesthetic Motor Imagery in Autism Spectrum Disorder: A Pilot Study Based on Eye-Tracking Methodology

Introduction

Social disturbance is a significant autism spectrum disorder (ASD) symptom. Action representation, which is a fundamental component of social interaction, can be investigated through kinesthetic motor imagery (KMI). KMI has been commonly studied with the well-developed laterality judgment paradigm, wherein participants are required to discriminate the laterality of a hand rotated by different angles along one or more axes. Here, we investigated the KMI processing in individuals with ASD by hand laterality judgment paradigm with eye-tracking methodology.

Methods

The current study included 22 participants with ASD and 22 typical developing (TD) peers matched for age, gender, and intelligence. Participants were asked to judge the laterality of hand-with-tooth brush images.

Results

Compared to the TD controls, individuals with ASD performed KMI with lower accuracy and longer response time in both correct and incorrect action conditions. The incorrect action representation had greater effect on KMI for individuals with ASD. Differences in eye-movement patterns were also observed, characterized by individuals with ASD were more focused on the object area while TD peers were more focused on the hand area.

Conclusion

Results suggest that while altered KMI performance was observed, the incorrect action representation elicited more engagement of KMI in both groups. The object-centered eye-movement pattern may contribute to the refine of motor simulation intervention for individuals with ASD.

Are there dedicated neural mechanisms for imitation? A study of grist and mills

Are there brain regions that are specialized for the execution of imitative actions? We compared two hypotheses of imitation: the mirror neuron system (MNS) hypothesis predicts frontal and parietal engagement which is specific to imitation, while the Grist-Mills hypothesis predicts no difference in brain activation between imitative and matched non-imitative actions. Our delayed imitation fMRI paradigm included two tasks, one where correct performance was defined by a spatial rule and another where it was defined by an item-based rule. For each task, participants could learn a sequence from a video of a human hand performing the task, from a matched "Ghost" condition, or from text instructions. When participants executed actions after seeing the Hand demonstration (compared to Ghost and Text demonstrations), no activation differences occurred in frontal or parietal regions; rather, activation was localized primarily to occipital cortex. This adds to a growing body of evidence which indicates that imitation-specific responses during action execution do not occur in canonical mirror regions, contradicting the mirror neuron system hypothesis. However, activation differences did occur between action execution in the Hand and Ghost conditions outside MNS regions, which runs counter to the Grist-Mills hypothesis. We conclude that researchers should look beyond these hypotheses as well as classical MNS regions to describe the ways in which imitative actions are implemented by the brain.

Motor learning without physical practice: The effects of combined action observation and motor imagery practice on cup-stacking speed

In this study we explored training effects for combined action observation and motor imagery (AO + MI) instructions on a complex cup-stacking task, without physical practice. Using a Graeco-Latin Square design, we randomly assigned twenty-six participants into four groups. This counterbalanced the within-participant factor of practice condition (AO + MI, AO, MI, Control) across four cup-stacking tasks, which varied in their complexity. On each of the three consecutive practice days participants experienced twenty trials under each of the three mental practice conditions. On each trial, a first-person perspective video depicted bilateral cup-stacking performed by an experienced model. During AO, participants passively observed this action, responding only to occasional colour cues. For AO + MI, participants imagined performing the observed action and synchronised their concurrent MI with the display. For MI, a sequence of pictures cued imagery of each stage of the task. Analyses revealed a significant main effect of practice condition both at the 'surprise' post-test (Day 3) and at the one-week retention test. At both time points movement execution times were significantly shorter for AO + MI compared with AO, MI and the Control. Execution times were also shorter overall at the retention compared with the post-test. These results demonstrate that a complex novel motor task can be acquired without physical training. Practitioners can therefore use AO + MI practice to supplement physical practice and optimise skill learning.

Enhancing upper-limb neurorehabilitation in chronic stroke survivors using combined action observation and motor imagery therapy

Introduction

For people who have had a stroke, recovering upper-limb function is a barrier to independence. When movement is difficult, mental practice can be used to complement physical therapy. In this within-participants study we investigated the effects of combined action observation and motor imagery (AO + MI) therapy on upper-limb recovery in chronic stroke survivors.

Methods

A Graeco-Latin Square design was used to counterbalance four mental practice conditions (AO + MI, AO, MI, Control) across four cup-stacking tasks of increasing complexity. Once a week, for five consecutive weeks, participants (n = 10) performed 16 mental practice trials under each condition. Each trial displayed a 1st person perspective of a cup-stacking task performed by an experienced model. For AO, participants watched each video and responded to an occasional color cue. For MI, participants imagined the effort and sensation of performing the action; cued by a series of still-images. For combined AO + MI, participants observed a video of the action while they simultaneously imagined performing the same action in real-time. At three time points (baseline; post-test; two-week retention test) participants physically executed the three mentally practiced cup-stacking tasks, plus a fourth unpractised sequence (Control), as quickly and accurately as possible.

Results

Mean movement execution times were significantly reduced overall in the post-test and the retention test compared to baseline. At retention, movement execution times were significantly shorter for combined AO + MI compared to both MI and the Control. Individual participants reported clinically important changes in quality of life (Stroke Impact Scale) and positive qualitative experiences of AO + MI (social validation).

Discussion

These results indicate that when physical practice is unsuitable, combined AO + MI therapy could offer an effective adjunct for neurorehabilitation in chronic stroke survivors.

TMS over dorsolateral prefrontal cortex affects the timing of motor imagery but not overt action: Further support for the motor-cognitive model

The Motor-Cognitive model suggests a functional dissociation between motor imagery and overt action, in contrast to the Functional Equivalence view of common processes between the two behaviours. According to the Motor-Cognitive model, motor imagery differs from overt action primarily through the use of executive resources to monitor and elaborate a motor image during execution, which can result in a lack of correspondence between motor imagery and its overt action counterpart. The present study examined the importance of executive resources in motor imagery by using TMS to impair the function of the dorsolateral prefrontal cortex while measuring the time to complete imagined versus overt actions. In two experiments, TMS over the dorsolateral prefrontal cortex slowed motor imagery but did not affect overt actions. TMS over the same region also interfered with performance of a mental calculation task, though it did not reliably affect less demanding cognitive tasks also thought to rely on executive functions. Taken together, these results were consistent with the Motor-Cognitive model but not with the idea of functional equivalence. The implications of these results for the theoretical understanding of motor imagery, and potential applications of the Motor-Cognitive model to the use of motor imagery in training and rehabilitation, are discussed.

Enhancing motor imagery practice using synchronous action observation

In this paper, we discuss a variety of ways in which practising motor actions by means of motor imagery (MI) can be enhanced via synchronous action observation (AO), that is, by AO + MI. We review the available research on the (mostly facilitatory) behavioural effects of AO + MI practice in the early stages of skill acquisition, discuss possible theoretical explanations, and consider several issues related to the choice and presentation schedules of suitable models. We then discuss considerations related to AO + MI practice at advanced skill levels, including expertise effects, practical recommendations such as focussing attention on specific aspects of the observed action, using just-ahead models, and possible effects of the perspective in which the observed action is presented. In section "Coordinative AO + MI", we consider scenarios where the observer imagines performing an action that complements or responds to the observed action, as a promising and yet under-researched application of AO + MI training. In section "The dual action simulation hypothesis of AO + MI", we review the neurocognitive hypothesis that AO + MI practice involves two parallel action simulations, and we consider opportunities for future research based on recent neuroimaging work on parallel motor representations. In section "AO + MI training in motor rehabilitation", we review applications of AO, MI, and AO + MI training in the field of neurorehabilitation. Taken together, this evidence-based, exploratory review opens a variety of avenues for future research and applications of AO + MI practice, highlighting several clear advantages over the approaches of purely AO- or MI-based practice.

Corticomotor Plasticity Underlying Priming Effects of Motor Imagery on Force Performance

The neurophysiological processes underlying the priming effects of motor imagery (MI) on force performance remain poorly understood. Here, we tested whether the priming effects of embedded MI practice involved short-term changes in corticomotor connectivity. In a within-subjects counterbalanced experimental design, participants (n = 20) underwent a series of experimental sessions consisting of successive maximal isometric contractions of elbow flexor muscles. During inter-trial rest periods, we administered MI, action observation (AO), and a control passive recovery condition. We collected electromyograms (EMG) from both agonists and antagonists of the force task, in addition to electroencephalographic (EEG) brain potentials during force trials. Force output was higher during MI compared to AO and control conditions (both p < 0.01), although fatigability was similar across experimental conditions. We also found a weaker relationship between triceps brachii activation and force output during MI and AO compared to the control condition. Imaginary coherence topographies of alpha (8−12 Hz) oscillations revealed increased connectivity between EEG sensors from central scalp regions and EMG signals from agonists during MI, compared to AO and control. Present results suggest that the priming effects of MI on force performance are mediated by a more efficient cortical drive to motor units yielding reduced agonist/antagonist coactivation.

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.

Decoding trajectories of imagined hand movement using electrocorticograms for brain-machine interface

OBJECTIVE

Reaching hand movement is an important motor skill actively examined in brain-computer interface (BCI). Among various components of movement analyzed is the hand's trajectory, which describes the hand's continuous positions in three-dimensional space. While a large body of studies have investigated the decoding of real movements and the reconstruction of real hand movement trajectories from neural signals, fewer studies have attempted to decode the trajectory of imagined hand movement. To develop BCI systems for patients with hand motor dysfunctions, the systems essentially require to achieve movement-free control of external devices, which is only possible through successful decoding of purely imagined hand movement.

APPROACH

To achieve this goal, this study used a machine learning technique (i.e., the variational Bayesian least square) to analyze the electrocorticogram (ECoG) of eighteen epilepsy patients obtained from when they performed movement execution (ME) and kinesthetic movement imagination (KMI) of the reach-and-grasp hand action.

MAIN RESULTS

The variational Bayesian decoding model was able to successfully predict the imagined trajectories of hand movement significantly above chance level. The Pearson's correlation coefficient between imagined and predicted trajectories was 0.3393 and 0.4936 for the KMI (KMI trials only) and MEKMI paradigm (alternating trials of ME and KMI) respectively.

SIGNIFICANCE

This study demonstrated a high accuracy of prediction for trajectories of imagined hand movement, and more importantly, higher decoding accuracy of imagined trajectories in the MEKMI paradigm than in the KMI paradigm solely.

Effect of skill proficiency on motor imagery ability between amateur dancers and non-dancers

Evidence has shown that athletes with high motor skill proficiency possess higher motor imagery ability than those with low motor skill proficiency. However, less is known whether this superiority in motor imagery ability emerges over amateur athletes. To address the issue, the present study aimed to investigate the individual differences in motor imagery ability between amateur dancers and non-dancers. Forty participants completed a novel dance movement reproduction task and measures of the vividness of visual imagery questionnaire (VVIQ) and the vividness of motor imagery questionnaire (VMIQ). The results showed that, relative to non-dancers, amateur dancers had higher ability of motor imagery to reproduce the lower-limb and upper-limb dance movements during the dance movement reproduction task. Besides, amateur dancers displayed higher abilities of the visual motor imagery and the kinesthetic imagery, but comparable visual imagery ability as the non-dancers. These findings suggest that the mental representation of motors but not the visual is affected by the motor skill levels, due to the motor imagery practice in sports amateurs.

The "Mirror Effect Plus Protocol" for acute Bell's palsy: A randomized controlled trial with 1-year follow-up

Objective

To study the effects of the “Mirror Effect Plus Protocol” (MEPP) on global facial function in acute and severe Bell's Palsy.

Design

Single blind and randomized controlled trial to compare the effects of basic counseling (control group) versus MEPP (experimental group) over one year.

Setting

Outpatient clinic following referrals from Emergency or Otorhinolaryngology Departments.

Subjects

40 patients (n = 20 per group) with moderately severe to total palsy who received standard medication were recruited within 14 days of onset. Baseline characteristics were comparable between the groups.

Interventions

The experimental group received the MEPP program (motor imagery + manipulations + facial mirror therapy) while the control group received basic counseling. Both groups met the clinician monthly until 6 months and at one-year post-onset for assessments.

Outcome measures

Facial symmetry, synkinesis, and quality of life were measured using standardized scales. Perceived speech intelligibility was rated before and after therapy by naïve judges.

Results

Descriptive statistics demonstrated improvements in favor of the MEPP for each measured variable. Significant differences were found for one facial symmetry score (House-Brackmann 2.0 mean (SD) = 7.40 (3.15) for controls versus 5.1 (1.44) for MEPP), for synkinesis measures (p = 0.008) and for quality-of-life ratings (mean (SD) score = 83.17% (17.383) for controls versus 98.36% (3.608) for MEPP (p = 0.002)). No group difference was found for perceived speech intelligibility.

Conclusion

The MEPP demonstrates promising long-term results when started during the acute phase of moderately severe to total Bell's Palsy.

Hierarchical Human-Inspired Control Strategies for Prosthetic Hands

The abilities of the human hand have always fascinated people, and many studies have been devoted to describing and understanding a mechanism so perfect and important for human activities. Hand loss can significantly affect the level of autonomy and the capability of performing the activities of daily life. Although the technological improvements have led to the development of mechanically advanced commercial prostheses, the control strategies are rather simple (proportional or on/off control). The use of these commercial systems is unnatural and not intuitive, and therefore frequently abandoned by amputees. The components of an active prosthetic hand are the mechatronic device, the decoding system of human biological signals into gestures and the control law that translates all the inputs into desired movements. The real challenge is the development of a control law replacing human hand functions. This paper presents a literature review of the control strategies of prosthetics hands with a multiple-layer or hierarchical structure, and points out the main critical aspects of the current solutions, in terms of human's functions replicated with the prosthetic device. The paper finally provides several suggestions for designing a control strategy able to mimic the functions of the human hand.

A neural signature for combined action observation and motor imagery? An fNIRS study into prefrontal activation, automatic imitation, and self-other perceptions

INTRODUCTION

Research indicates that both observed and imagined actions can be represented in the brain as two parallel sensorimotor representations. One proposal is that higher order cognitive processes would align these two hypothetical action simulations.

METHODS

We investigated this hypothesis using an automatic imitation paradigm, with functional near-infrared spectroscopy recordings over the prefrontal cortex during different motor simulation states. On each trial, participants (n = 14) observed a picture of a rhythmical action (instructed action) followed by a distractor movie showing the same or different action. Participants then executed the instructed action. Distractor actions were manipulated to be fast or slow, and instructions were manipulated during distractor presentation: action observation (AO), combined action observation and motor imagery (AO+MI) and observe to imitate (intentional imitation). A pure motor imagery (MI) condition was also included.

RESULTS

Kinematic analyses showed that although distractor speed effects were significant under all instructions (shorter mean cycle times in execution for fast compared to slow trials), this imitation bias was significantly stronger for combined AO+MI than both AO and MI, and stronger for intentional imitation than the other three automatic imitation conditions. In the left prefrontal cortex, cerebral oxygenation was significantly greater for combined AO+MI than all other instructions. Participants reported that their representation of the self overlapped with the observed model significantly more during AO+MI than AO.

CONCLUSION

Left prefrontal activation may therefore be a neural signature of AO+MI, supporting attentional switching between concurrent representations of self (MI, top-down) and other (AO, bottom-up) to increase imitation and perceived closeness.

Brain Cortical Activation during Imagining of the Wrist Movement Using Functional Near-Infrared Spectroscopy (fNIRS)

Background:

fNIRS is a useful tool designed to record the changes in the density of blood’s oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) molecules during brain activity. This method has made it possible to evaluate the hemodynamic changes of the brain during neuronal activity in a completely non-aggressive manner.

Objective:

The present study has been designed to investigate and evaluate the brain cortex activities during imagining of the execution of wrist motor tasks by comparing fMRI and fNIRS imaging methods.

Material and Methods:

This novel observational Optical Imaging study aims to investigate the brain motor cortex activity during imagining of the right wrist motor tasks in vertical and horizontal directions. To perform the study, ten healthy young right-handed volunteers were asked to think about right-hand movements in different directions according to the designed movement patterns. The required data were collected in two wavelengths, including 845 and 763 nanometers using a 48 channeled fNIRS machine.

Results:

Analysis of the obtained data showed the brain activity patterns during imagining of the execution of a movement are formed in various points of the motor cortex in terms of location. Moreover, depending on the direction of the movement, activity plans have distinguishable patterns. The results showed contralateral M1 was mainly activated during imagining of the motor cortex (p<0.05).

Conclusion:

The results of our study showed that in brain imaging, it is possible to distinguish between patterns of activities during wrist motion in different directions using the recorded signals obtained through near-infrared Spectroscopy. The findings of this study can be useful in further studies related to movement control and BCI.

Neural decoding of gait phases during motor imagery and improvement of the decoding accuracy by concurrent action observation

Objective. Brain decoding of motor imagery (MI) not only is crucial for the control of neuroprosthesis but also provides insights into the underlying neural mechanisms. Walking consists of stance and swing phases, which are associated with different biomechanical and neural control features. However, previous knowledge on decoding the MI of gait is limited to simple information (e.g. the classification of 'walking' and 'rest').Approach. Here, we investigated the feasibility of electroencephalogram (EEG) decoding of the two gait phases during the MI of walking and whether the combined use of MI and action observation (AO) would improve decoding accuracy.Main results. We demonstrated that the stance and swing phases could be decoded from EEGs during MI or AO alone. We also demonstrated the decoding accuracy during MI was improved by concurrent AO. The decoding models indicated that the improved decoding accuracy following the combined use of MI and AO was facilitated by the additional information resulting from the concurrent cortical activations related to sensorimotor, visual, and action understanding systems associated with MI and AO.Significance. This study is the first to show that decoding the stance versus swing phases during MI is feasible. The current findings provide fundamental knowledge for neuroprosthetic design and gait rehabilitation, and they expand our understanding of the neural activity underlying AO, MI, and AO + MI of walking.Novelty and significanceBrain decoding of detailed gait-related information during motor imagery (MI) is important for brain-computer interfaces (BCIs) for gait rehabilitation. This study is the first to show the feasibility of EEG decoding of the stance versus swing phases during MI. We also demonstrated that the combined use of MI and action observation (AO) improves decoding accuracy, which is facilitated by the concurrent and synergistic involvement of the cortical activations for MI and AO. These findings extend the current understanding of neural activity and the combined effects of AO and MI and provide a basis for effective techniques for walking rehabilitation.

Sonification of combined action observation and motor imagery: Effects on corticospinal excitability

Action observation and motor imagery are valuable strategies for motor learning. Their simultaneous use (AOMI) increases neural activity, with related benefits for motor learning, compared to the two strategies alone. In this study, we explored how sonification influences AOMI. Twenty-five participants completed a practice block based on AOMI, motor imagery and physical execution of the same action. Participants were divided into two groups: An experimental group that practiced with sonification during AOMI (sAOMI), and a control group, which did not receive any extrinsic feedback. Corticospinal excitability at rest and during action observation and AOMI was assessed before and after practice, with and without sonification sound, to test the development of an audiomotor association. The practice block increased corticospinal excitability in all testing conditions, but sonification did not affect this. In addition, we found no differences in action observation and AOMI, irrespective of sonification. These results suggest that, at least for simple tasks, sonification of AOMI does not influence corticospinal excitability; In these conditions, sonification may have acted as a distractor. Future studies should further explore the relationship between task complexity, value of auditory information and action, to establish whether sAOMI is a valuable for motor learning.

Combined action observation and motor imagery: An intervention to combat the neural and behavioural deficits associated with developmental coordination disorder

Action observation (AO) and motor imagery (MI) have been used separately across different populations to alleviate movement impairment. Recently these two forms of covert motor simulation have been combined (combined action observation and motor imagery; AOMI), resulting in greater neurophysiological activity in the motor system, and more favourable behavioural outcomes when compared to independent AO and MI. This review aims to outline how some of the neural deficits associated with developmental coordination disorder (DCD) are evident during AO and MI, and highlight how these motor simulation techniques have been used independently to improve motor skill learning in children in this population. The growing body of evidence indicating that AOMI is superior to the independent use of either AO and MI is then synthesised and discussed in the context of children with DCD. To conclude, recommendations to optimise the delivery of AOMI for children with DCD are provided and future avenues for research are highlighted.

Language reorganization after resection of low-grade gliomas: an fMRI task based connectivity study

Few studies addressed the evolution of brain activity before and after brain tumor resection. Using a fMRI naming task, we evaluated possible underlying plasticity phenomena. Thirty-two patients with left low-grade gliomas (16 women; age = 38.6 ± 8.31 years) and 19 healthy controls (7 women; age = 42.4 ± 12.1) were included in the study. An overt picture-naming task (DO80) was performed pre and post (3 months) surgery, as well as within the MRI in a covert manner. Exams included an injected 3DT1, a T2FLAIR, a DTI and a GE-EPI (task) sequence. Activations maps were compared with picture naming score, FA and MD maps were estimated, a VLSM analysis was performed on tumor masks, and disconnectome maps were reconstructed. Pre-surgery, the left parahippocampal gyrus (LPH) was inversely associated with task performance. Increased pre-post surgery left lingual gyrus (LLG) activity was found related to decreased picture naming performance. The evolution of left lingual gyrus (LLG) activity was negatively associated with the evolution of picture naming performance. In controls, the LPH was functionally connected to the right precentral gyrus (RPCG) and slightly to the LLG. This was not clearly retrieved in the patient group. Preoperatively, the LLG was connected to the left planum temporale and to the right lingual gyrus. The same result was found for controls. Postoperatively, the LLG was only connected to the RPCG. No association was found between evolution of FA/MD and evolution of picture naming performance. There is not one unique pattern of pre- and postoperative plasticity concerning picture-naming performance in DLGG patients.

Frontal brain areas are more involved during motor imagery than during motor execution/preparation of a response sequence

Results of several neuroimaging studies support the functional equivalence model, which states that motor imagery (MI) and motor execution (ME) involve the same processes, except for the final execution component. In contrast, the motor-cognitive model implies that MI additionally involves frontal executive control processes. However, according to some authors MI may actually be more comparable to motor preparation (MP). In the current electroencephalographic study, a version of the discrete sequence production paradigm was employed in which human participants initially had to prepare a sequence of five finger movements that subsequently had to be executed, imagined, or withheld. MI, ME, and MP were compared by computing event-related (de)-synchronization in the theta, alpha/mu, and beta bands. Results revealed a major increase in frontal theta power during MI as compared to ME and MP. At the end of the examined intervals, a posterior reduction in alpha power was present during ME and MP, but not during MI. Finally, above sensorimotor areas a decrease in beta power was observed that was most pronounced in the case of ME. The increase of frontal theta activity during MI may reflect increased effort, while the absence of a reduction in posterior alpha power suggests no major involvement of visuospatial attention and/or visual imagery. The present findings favor the motor-cognitive model, as it predicts extra involvement of frontal executive processes during MI.

Brain Patterns During Single- and Dual-Task Leg Movements

The brain is able to engage in dual tasks such as motor imagery (MI) and action observation (AO) or motor execution (ME) with action observation. In this study, we have quantitatively compared event-related desynchronization (ERD) patterns during tasks of pure MI, MI with AO (O-MI), ME, and ME with AO (O-ME) of the leg to investigate the underlying neuronal mechanisms using EEG. Subjects were instructed to imagine or perform rhythmical actions while watching a video of leg movements during O-MI and O-ME tasks; In contrast, subjects imagined and performed the leg movements without observing any video during pure MI and ME tasks. We noticed that the amplitude of ERDs from MI, O-MI, ME and O-ME sequentially increases in central regions of the brain. These quantified ERD patterns in EEG were used to study the differences of brain oscillatory changes among the four tasks. We found that ERDs in motor area were more distinct in O-MI, compared with pure MI. These results suggest that O-MI produced stronger motor activations than MI. Plus, O-ME showed significantly greater activations than ME in the beta band. O-ME has produced stronger neurophysiological effects than MI, and stronger behavioral effects than ME. These empirical results do provide convincing evidence of the dual tasks such combined MI or ME with action observation on brain pattern changes. The video of the goal-directed leg movements is most likely able to improve the ability of performing or imagining movements. O-MI and O-ME may get better and closer therapeutic effects in leg rehabilitation and motor skill training. Furthermore, the extent analysis of ERD may provide the basis for evaluating the ability of O-MI and O-ME in leg rehabilitation and motor skill training.

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.

Graph Theoretic Analysis Reveals Intranasal Oxytocin Induced Network Changes Over Frontal Regions

In this study, we aim to elucidate how intranasal oxytocin modulates brain network characteristics, especially over the frontal network. As an essential brain hub of social cognition and emotion regulation, we also explore the association between graphic properties of the frontal network and individual personality traits under oxytocin (OT) administration. Fifty-nine male participants administered intranasal OT or placebo were followed by resting-state fMRI scanning. The correlation-based network model was applied to study OT modulation effects. We performed community detection algorithms and conducted further network analyses, including clustering coefficient, average shortest path and eigenvector centrality. In addition, we conducted a correlation analysis between clustering coefficients and the self-assessed psychological scales. Modular organizations in the OT group reveal integrations of the frontoparietal network (FPN) and the default mode network (DMN) over frontal regions. Results show that frontal nodes within the FPN are characterized by lower clustering coefficients and higher average shortest path values compared to the placebo group. Notably, these modulation effects on frontal network property are associated with Interpersonal Reactivity Index (IRI) fantasy value. Our results suggest that OT elevates integrations between FPN, DMN and limbic system as well as reduces small-worldness within the FPN. Our results support graph theoretic analysis as a potential tool to assess OT induced effects on the information integration in the frontal network.

The human primary somatosensory cortex encodes imagined movement in the absence of sensory information

Classical systems neuroscience positions primary sensory areas as early feed-forward processing stations for refining incoming sensory information. This view may oversimplify their role given extensive bi-directional connectivity with multimodal cortical and subcortical regions. Here we show that single units in human primary somatosensory cortex encode imagined reaches in a cognitive motor task, but not other sensory–motor variables such as movement plans or imagined arm position. A population reference-frame analysis demonstrates coding relative to the cued starting hand location suggesting that imagined reaching movements are encoded relative to imagined limb position. These results imply a potential role for primary somatosensory cortex in cognitive imagery, engagement during motor production in the absence of sensation or expected sensation, and suggest that somatosensory cortex can provide control signals for future neural prosthetic systems.

Matiar Jafari, Tyson Aflalo et al. show that the human primary somatosensory cortex is activated when subjects imagine reaches in a cognitive motor task, but not when they plan movement or imagine a static limb position. These results highlight a role for this region in cognitive imagery and motor control in the absence of sensory information.

Brain reactions to the use of sensorized hand prosthesis in amputees

OBJECTIVE

We investigated for the first time the presence of chronic changes in the functional organization of sensorimotor brain areas induced by prolonged training with a bidirectional hand prosthesis.

METHODS

A multimodal neurophysiological and neuroimaging evaluation of brain functional changes occurring during training in five consecutive amputees participating to experimental trials with robotic hands over a period of 10 years was carried out. In particular, modifications to the functional anatomy of sensorimotor brain areas under resting conditions were explored in order to check for eventual changes with respect to baseline.

RESULTS

Full evidence is provided to demonstrate brain functional changes, and some of them in both the hemispheres and others restricted to the hemisphere contralateral to the amputation/prosthetic hand.

CONCLUSIONS

The study describes a unique experimental experience showing that brain reactions to the prolonged use of an artificial hand can be tracked for a tailored approach to a fully embedded artificial upper limb for future chronic uses in daily activities.

Phase dependent modulation of cortical activity during action observation and motor imagery of walking: An EEG study

Action observation (AO) and motor imagery (MI) are motor simulations which induce cortical activity related to execution of observed and imagined movements. Neuroimaging studies have mainly investigated where the cortical activities during AO and MI of movements are activated and if they match those activated during execution of the movements. However, it remains unclear how cortical activity is modulated; in particular, whether activity depends on observed or imagined phases of movements. We have previously examined the neural mechanisms underlying AO and MI of walking, focusing on the combined effect of AO with MI (AO+MI) and phase dependent modulation of corticospinal and spinal reflex excitability. Here, as a continuation of our previous studies, we investigated cortical activity depending on gait phases during AO and AO+MI of walking by using electroencephalography (EEG); 64-channel EEG signals were recorded in which participants observed walking with or without imagining it, respectively. EEG source and spectral analyses showed that, in the sensorimotor cortex during AO+MI and AO, the alpha and beta power were decreased, and power spectral modulations depended on walking phases. The phase dependent modulations during AO+MI, but not during AO, were like those which occur during actual walking as reported by previous walking studies. These results suggest that combinatory effects of AO+MI could induce parts of the phase dependent activation of the sensorimotor cortex during walking even without any movements. These findings would extend understanding of the neural mechanisms underlying walking and cognitive motor processes and provide clinically beneficial information towards rehabilitation for patients with neurological gait dysfunctions.

The Understudied Side of Contemplation: Words, Images, and Intentions in a Syncretic Spiritual Practice

The science of contemplation has focused on mindfulness in a manner quite disproportionate to its use in contemplative traditions. Mindfulness, as understood within the scientific community, is a practice that invites practitioners to disattend to words and images. The practitioner is meant to experience things as they "really are," unfolding here and now in the flux of embodied sensations. Yet the use of words and images, together with intentions, is a far more common contemplative practice. The authors present ethnographic research with a syncretic contemplative tradition, Integral Transformative practice (ITP), which grew out of the Human Potential Movement of the 1960s. The authors focus on the practice of "affirmations," in which practitioners seek to actualize spiritual goals by imagining future possibilities. Our ethnographic account invites new avenues for psychological research to illuminate the role of words and images in contemplation.

Cortical Plasticity in Rehabilitation for Upper Extremity Peripheral Nerve Injury: A Scoping Review

IMPORTANCE

Poor outcomes after upper extremity peripheral nerve injury (PNI) may arise, in part, from the challenges and complexities of cortical plasticity. Occupational therapy practitioners need to understand how the brain changes after peripheral injury and how principles of cortical plasticity can be applied to improve rehabilitation for clients with PNI.

OBJECTIVE

To identify the mechanisms of cortical plasticity after PNI and describe how cortical plasticity can contribute to rehabilitation.

DATA SOURCES

PubMed and Embase (1900-2017) were searched for articles that addressed either (1) the relationship between PNI and cortical plasticity or (2) rehabilitative interventions based on cortical plastic changes after PNI.

Study Selection and Data Collectio

: PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. Articles were selected if they addressed all of the following concepts: human PNI, cortical plasticity, and rehabilitation. Phantom limb pain and sensation were excluded.

FINDINGS

Sixty-three articles met the study criteria. The most common evidence level was Level V (46%). We identified four commonly studied mechanisms of cortical plasticity after PNI and the functional implications for each. We found seven rehabilitative interventions based on cortical plasticity: traditional sensory reeducation, activity-based sensory reeducation, selective deafferentation, cross-modal sensory substitution, mirror therapy, mental motor imagery, and action observation with simultaneous peripheral nerve stimulation.

CONCLUSION AND RELEVANCE

The seven interventions ranged from theoretically well justified (traditional and activity-based sensory reeducation) to unjustified (selective deafferentation). Overall, articles were heterogeneous and of low quality, and future research should prioritize randomized controlled trials for specific neuropathies, interventions, or cortical plasticity mechanisms.

WHAT THIS ARTICLE ADDS

This article reviews current knowledge about how the brain changes after PNI and how occupational therapy practitioners can take advantage of those changes for rehabilitation.

Examining the equivalence between imagery and execution - Do imagined and executed movements code relative environmental features?

Imagined actions engage some of the same neural substrates and related sensorimotor codes as executed actions. The equivalency between imagined and executed actions has been frequently demonstrated by the mental and physical chronometry of movements; namely, the imagination and execution of aiming movements in a Fitts paradigm. The present study aimed to examine the nature or extent of this equivalence, and more specifically, whether imagined movements encompass the relative environmental features as do executed movements. In two separate studies, participants completed a series of imagined or executed reciprocal aiming movements between standard control targets (no annuli), perceptually small targets (large annuli) and perceptually large targets (small annuli) (Ebbinghaus illusions). The findings of both studies replicated the standard positive relation between movement time and index of difficulty for imagined and executed movements. Furthermore, movement times were longer for targets with surrounding annuli compared to the movement times without the annuli suggesting a general interference effect. Hence, the surrounding annuli caused a longer time, independent of the illusory target size, most likely to avoid a potential collision and more precisely locate the endpoint. Most importantly, this feature could not be discriminated as a function of the task (imagined vs. executed). These findings lend support to the view of a common domain for imagined and executed actions, while elaborating on the precision of their equivalence.

Dissociation between cortical and spinal excitability of the antagonist muscle during combined motor imagery and action observation

Inhibitory neural control of antagonist muscle is one of the fundamental neural mechanism of coordinated human limb movement. Previous studies have revealed that motor execution (ME) and motor imagery (MI) share many common neural substrates; however, whether inhibitory neural activity occurs during MI remains unknown. In addition, recent studies have demonstrated that a combined MI and action observation (MI + AO) produces strong neurophysiological changes compared with MI or AO alone. Therefore, we investigated inhibitory changes in cortical and spinal excitability of the antagonist muscle during MI + AO and ME. Single-pulse transcranial magnetic stimulation (TMS) experiments revealed that corticospinal excitability of the antagonist muscle was decreased during MI + AO. Conversely, F-wave experiments showed that F-wave persistence of the antagonist muscle increased. Paired-pulse TMS experiment also demonstrated that short-interval intracortical inhibition (SICI) did not contribute to this inhibition. Therefore, cortical mediated inhibition, except for SICI, may be related to this inhibition. Conversely, such clear inhibition of the antagonist muscle was not observed during ME, presumably owing to the effects of muscle contraction to decelerate the movements and/or sensory input accompanying the joint movements. These findings provide important insights into the neurophysiological differences between MI + AO and ME.

Analgesic Effects Evoked by Real and Imagined Acupuncture: A Neuroimaging Study

Acupuncture can provide therapeutic analgesic benefits but is limited by its cost and scheduling difficulties. Guided imagery is a commonly used method for treating many disorders, such as chronic pain. The present study examined a novel intervention for pain relief that integrates acupuncture with imagery called video-guided acupuncture imagery treatment (VGAIT). A total of 27 healthy subjects were recruited for a crossover-design study that included 5 sessions administered in a randomized order (i.e., baseline and 4 different interventions). We investigated changes in pain threshold and fMRI signals modulated by: 1) VGAIT, watching a video of acupuncture previously administered on the participant's own body at baseline while imagining it being concurrently applied; 2) a VGAIT control condition, watching a video of a cotton swab touching the skin; 3) real acupuncture; and 4) sham acupuncture. Results demonstrated that real acupuncture and VGAIT significantly increased pain threshold compared with respective control groups. Imaging showed that real acupuncture produced greater activation of the insula compared with VGAIT. VGAIT produced greater deactivation at the rostral anterior cingulate cortex. Our findings demonstrate that VGAIT holds potential clinical value for pain management.

Dynamic motor imagery mentally simulates uncommon real locomotion better than static motor imagery both in young adults and elderly

A new form of Motor Imagery (MI), called dynamic Motor Imagery (dMI) has recently been proposed. The dMI adds to conventional static Motor Imagery (sMI) the presence of simultaneous actual movements partially replicating those mentally represented. In a previous research conducted on young participants, dMI showed to be temporally closer than sMI in replicating the real performance for some specific locomotor conditions. In this study, we evaluated if there is any influence of the ageing on dMI. Thirty healthy participants were enrolled: 15 young adults (27.1±3.8 y.o.) and 15 older adults (65.9±9.6y.o.). The performance time and the number of steps needed to either walk to a target (placed at 10m from participants) or to imagine walking to it, were assessed. Parameters were measured for sMI, dMI and real locomotion (RL) in three different locomotor conditions: forward walking (FW), backward walking (BW), and lateral walking (LW). Temporal performances of sMI and dMI did not differ between RL in the FW, even if significantly different to each other (p = 0.0002). No significant differences were found for dMI with respect to RL for LW (p = 0.140) and BW (p = 0.438), while sMI was significantly lower than RL in LW (p<0.001). The p-value of main effect of age on participants’ temporal performances was p = 0.055. The interaction between age and other factors such as the type of locomotion (p = 0.358) or the motor condition (p = 0.614) or third level interaction (p = 0.349) were not statistically significant. Despite a slight slowdown in the performance of elderly compared to young participants, the temporal and spatial accuracy was better in dMI than sMI in both groups. Motor imagery processes may be strengthened by the feedback generated through dMI, and this effect appears to be unaffected by age.

Evidence for we-representations during joint action planning

Do people engaged in joint action form action plans that specify joint outcomes at the group level? EEG was recorded from pairs of participants who performed coordinated actions that could result in different postural configurations. To isolate individual and joint action planning processes, a pre-cue specified in advance the individual actions and/or the joint configuration. Participants had 1200 ms to prepare their actions. Then a Go cue specified all action parameters and participants performed a synchronized action as quickly as possible. Action onsets were shorter when the pre-cue specified the joint configuration, regardless of whether individual action was also specified. EEG analyses showed that specifying joint action parameters in advance reduced ambiguity in a structured joint action plan (reflected in the decrease of the amplitude of the P600) and helped with representing action goals and interpersonal coordination patterns in sensorimotor brain areas (reflected in increased alpha/mu suppression and CNV amplitudes). These results provide clear evidence that joint action is driven not only by action plans that specify individual contributions, but also by action plans that specify joint action outcomes at the group level.

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People form individual and group-level representations during joint action planning.

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Information about joint configuration benefits task performance.

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Information about joint configuration reduces ambiguity in joint task representation.

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Evidence for predictive “we-representations” in the sensorimotor system.

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“We-representations” may be formed independently of “I” and “You” representations.

Starting and stopping movement by the primate brain

We review the current knowledge about the part that motor cortex plays in the preparation and generation of movement, and we discuss the idea that corticospinal neurons, and particularly those with cortico-motoneuronal connections, act as ‘command’ neurons for skilled reach-to-grasp movements in the primate. We also review the increasing evidence that it is active during processes such as action observation and motor imagery. This leads to a discussion about how movement is inhibited and stopped, and the role in these for disfacilitation of the corticospinal output. We highlight the importance of the non-human primate as a model for the human motor system. Finally, we discuss the insights that recent research into the monkey motor system has provided for translational approaches to neurological diseases such as stroke, spinal injury and motor neuron disease.

Can action observation modulate balance performance in healthy subjects?

Background

Action observation activates brain motor networks and, if followed by action imitation, it facilitates motor learning and functional recovery in patients with both neurological and musculoskeletal disorders. To date, few studies suggested that action observation plus imitation can improve balance skills; however, it is still unclear whether the simple repetitive observation of challenging balance tasks is enough to modify postural control. Thus, the primary aim of this study was to investigate whether repetitive action observation of balance exercises without imitation has the potential to improve balance performance; the secondary aim was to estimate the different training effects of action observation, action observation plus imitation and balance training relative to a control condition in healthy subjects.

Methods

Seventy-nine healthy young adults were randomly assigned to 4 groups: action observation, action observation plus imitation, balance training and control. The first three groups were trained for about 30 minutes every day for three weeks, whereas the control group received no training. Center of pressure path length and sway area were evaluated on a force platform at baseline and after training using posturographic tests with eyes open and closed.

Results

As expected, both action observation plus imitation and balance training groups compared to the control group showed balance improvements, with a medium to large effect size performing balance tasks with eyes open. Action observation without imitation group showed a balance improvement with eyes open, but without a significant difference relative to the control group.

Conclusions

Both action observation plus imitation and balance training have similar effects in improving postural control in healthy young subjects. Future studies on patients with postural instability are necessary to clarify whether AOT can induce longer lasting effects. Action observation alone showed a trend toward improving postural control in healthy subjects, suggesting the possibility to study its effects in temporarily immobilized diseased subjects.

Combined action observation and motor imagery therapy: a novel method for post-stroke motor rehabilitation

Cerebral vascular accidents (strokes) are a leading cause of motor deficiency in millions of people worldwide. While a complex range of biological systems is affected following a stroke, in this paper we focus primarily on impairments of the motor system and the recovery of motor skills. We briefly review research that has assessed two types of mental practice, which are currently recommended in stroke rehabilitation. Namely, action observation (AO) therapy and motor imagery (MI) training. We highlight the strengths and limitations in both techniques, before making the case for combined action observation and motor imagery (AO + MI) therapy as a potentially more effective method. This is based on a growing body of multimodal brain imaging research showing advantages for combined AO + MI instructions over the two separate methods of AO and MI. Finally, we offer a series of suggestions and considerations for how combined AO + MI therapy could be employed in neurorehabilitation.

Watch, Imagine, Attempt: Motor Cortex Single-Unit Activity Reveals Context-Dependent Movement Encoding in Humans With Tetraplegia

Planning and performing volitional movement engages widespread networks in the human brain, with motor cortex considered critical to the performance of skilled limb actions. Motor cortex is also engaged when actions are observed or imagined, but the manner in which ensembles of neurons represent these volitional states (VoSs) is unknown. Here we provide direct demonstration that observing, imagining or attempting action activates shared neural ensembles in human motor cortex. Two individuals with tetraplegia (due to brainstem stroke or amyotrophic lateral sclerosis, ALS) were verbally instructed to watch, imagine, or attempt reaching actions displayed on a computer screen. Neural activity in the precentral gyrus incorporated information about both cognitive state and movement kinematics; the three conditions presented overlapping but unique, statistically distinct activity patterns. These findings demonstrate that individual neurons in human motor cortex reflect information related to sensory inputs and VoS in addition to movement features, and are a key part of a broader network linking perception and cognition to action.

Enhanced Upper Extremity Functions with a Single Session of Action-Observation-Execution and Accelerated Skill Acquisition Program in Subacute Stroke

BACKGROUND

Action-observation-execution (AOE) primes physical training. We examined the immediate effect of AOE with accelerated skill acquisition program (ASAP) on dexterity in subacute stroke.

METHODS

Twelve individuals from 1 to 6 months after stroke were allocated into two groups by matching age and side of stroke. After AOE of 30 minutes, the experimental group received ASAP for 60 minutes whereas the control group received dose-equivalent usual care. The movement time (MT) and functional ability (FA) of hand items of the Wolf motor function test (WMFT), hand functions and global recovery of stroke impact scale (SIS), and intrinsic motivation items of stroke rehabilitation motivation scale were assessed at baseline, after training, and during one-week follow-up. Data were analyzed within and between the groups.

RESULTS

AOE significantly decreased MT of flipping cards of WMFT and hand functions of SIS. Total MT was markedly reduced. AOE with ASAP demonstrated significant group-by-time interactions on MT of lifting pencil of WMFT, total MT, and global recovery. Grip strength, FA, and hand functions were significantly improved only in the experimental group. Both groups improved motivation significantly.

CONCLUSIONS

The AOE with ASAP enhanced dexterity, which persisted for at least a week. This intervention might improve dexterity in subacute stroke.

TRIAL REGISTRATION NUMBER

This trial is registered with TCTR20161007001.

Real-Time Prediction of Observed Action Requires Integrity of the Dorsal Premotor Cortex: Evidence From Repetitive Transcranial Magnetic Stimulation

Studying brain mechanisms underlying the prediction of observed action, the dorsal premotor cortex (PMd) has been suggested a key area. The present study probed this notion using repetitive transcranial magnetic stimulation (rTMS) to test whether interference in this area would affect the accuracy in predicting the time course of object directed actions performed with the right hand. Young and healthy participants observed actions in short videos. These were briefly occluded from view for 600 ms and resumed immediately afterwards. The task was to continue the action mentally and to indicate after each occlusion, whether the action was resumed at the right moment (condition in-time) or shifted. In a first run, single-pulse transcranial magnetic stimulation (sTMS) was delivered over the left primary hand-area during occlusion. In the second run, rTMS over the left PMd was applied during occlusion in half of the participants [experimental group (EG)]. The control group (CG) received sham-rTMS over the same area. Under rTMS, the EG predicted less trials correctly than in the sTMS run. Sham-rTMS in the CG had no effects on prediction. The interference in PMd interacted with the type of manipulation applied to the action’s time course occasionally during occlusion. The performance decrease of the EG was most pronounced in conditions in which the continuations after occlusions were too late in the action’s course. The present results extend earlier findings suggesting that real-time action prediction requires the integrity of the PMd. Different functional roles of this area are discussed. Alternative interpretations consider either simulation of specific motor programming functions or the involvement of a feature-unspecific predictor.

Decoding intransitive actions in primary motor cortex using fMRI: toward a componential theory of 'action primitives' in motor cortex

Multivoxel pattern analysis (MVPA) over functional MRI data can distinguish neural representational states that do not differ in their overall amplitude of BOLD contrast. Here we used MVPA to test whether simple intransitive actions can be distinguished in primary motor cortex. Participants rotated and flexed each of their extremities (hands and feet) during fMRI scanning. The primary motor cortex for the hand/wrist was functionally defined in each hemisphere in each subject. Within those subject-specific ROIs, we found that the average amplitude of BOLD contrast for two different movements of the contralateral hand (rotation, flexion) were higher than for the ipsilateral hand, as well as movements by both feet; however, there was no difference in amplitude between the two different types of movements for the contralateral hand. Using multivoxel pattern analysis (linear correlation), we were able to distinguish the two movements for the contralateral hand. These findings demonstrate that simple intransitive actions can be distinguished in primary motor areas using multivoxel pattern analysis.

Motor Imagery during Action Observation of Locomotor Tasks Improves Rehabilitation Outcome in Older Adults after Total Hip Arthroplasty

This study aimed at determining whether the combination of action observation and motor imagery (AO + MI) of locomotor tasks could positively affect rehabilitation outcome after hip replacement surgery. Of initially 405 screened participants, 21 were randomly split into intervention group (N = 10; mean age = 64 y; AO + MI of locomotor tasks: 30 min/day in the hospital, then 3×/week in their homes for two months) and control group (N = 11, mean age = 63 y, active controls). The functional outcomes (Timed Up and Go, TUG; Four Step Square Test, FSST; and single- and dual-task gait and postural control) were measured before (PRE) and 2 months after surgery (POST). Significant interactions indicated better rehabilitation outcome for the intervention group as compared to the control group: at POST, the intervention group revealed faster TUG (p = 0.042), FSST (p = 0.004), and dual-task fast-paced gait speed (p = 0.022), reduced swing-time variability (p = 0.005), and enhanced cognitive performance during dual tasks while walking or balancing (p < 0.05). In contrast, no changes were observed for body sway parameters (p ≥ 0.229). These results demonstrate that AO + MI is efficient to improve motor-cognitive performance after hip surgery. Moreover, only parameters associated with locomotor activities improved whereas balance skills that were not part of the AO + MI intervention were not affected, demonstrating the specificity of training intervention. Overall, utilizing AO + MI during rehabilitation is advised, especially when physical practice is limited.