Motor Imagery

Optimizing neurofeedback (NF) and brain–computer interface (BCI) implementations constitutes a challenge across many fields and has so far been addressed by, among others, advancing signal processing methods or predicting the user’s control ability from neurophysiological or psychological measures. In comparison, how context factors influence NF/BCI performance is largely unexplored. We here investigate whether a competitive multi-user condition leads to better NF/BCI performance than a single-user condition. We implemented a foot motor imagery (MI) NF with mobile electroencephalography (EEG). Twenty-five healthy, young participants steered a humanoid robot in a single-user condition and in a competitive multi-user race condition using a second humanoid robot and a pseudo competitor. NF was based on 8–30 Hz relative event-related desynchronization (ERD) over sensorimotor areas. There was no significant difference between the ERD during the competitive multi-user condition and the si...

Motor Imagery provides a special context for representation of movements. This feature has been investigated in typical developing children in several studies, but there is little information in the field of motor imagery in children with autism. Therefore, the aim of the present study was to investigate this component in children with autism spectrum disorder aged 8 to 12 years compared to typical developing peers.
40 ASD children and 40 TD children who were age and IQ matched, purposefully and available selected and participated in the research voluntarily. To investigate motor imagery, the hand rotation paradigm in 3D software was used. The task involves two blocks of 12 hand-pattern which rotates randomly three times at six angles. The reaction time and error numbers were recorded as the performance scores of each subject. In order to analyze the data, two analysis of variance tests were used to evaluate and compare the reaction times and the U-man Whitney test used for the number of errors separately for back and palm view of hand.
The findings confirmed that children with autism are able to use this feature same TD, although this operation is less accurate and longer. So that in the reaction time and the number of error variables, the ASD group performed worse than TD peers.
Although the disorder may effect on cognitive function underlying motor behaviors in these children, nevertheless the capacity required to learn and develop motor skills in these children is developed, usable, and exploitable.

Brain activity during observation and imagery of gait was investigated. Sixteen subjects were scanned with a 3-Tesla MRI scanner while viewing six types of video clips: observation of gait movement (GO) from the third-person perspective, observation of stepping movement, observation of standing posture, "virtual walking" (VW) that was observation of visual scenes mimicking the visual afferent during walking, and the scrambled version of the GO and VW stimuli. In the VW condition, moving scenes provided a virtual visual environment in which subjects easily imagined as if they were actually walking from the first-person perspective. A behavioral experiment revealed a correlation of cadence during actual walking with that during imaginary walking under the influence of the VW stimuli, indicating that a gait planning mechanism was shared by actual walking and gait imagery. The VW condition activated the dorsal premotor cortex (PMd), supplementary motor area/cingulate motor area (SMA/CMA), parahippocampal gyrus, and subcortical nuclei. The GO stimuli yielded activation of the SMA, PMd, inferior frontal gyrus, and inferior parietal lobule. Moreover, the conjunction null test of GO and VW revealed common activity in the SMA/CMA and PMd, which were reportedly active during actual gait movement, in addition to visual areas. Detailed analyses of activity during stepping or standing observation supported the specificity of the SMA and PMd to GO. These findings suggest that motor planning centers of gait, including the SMA and PMd, are activated during both imagination (first-person perspective) and observation (third-person perspective) of gait behaviors.

Most contemporary text books of neurology and of psychology pay little attention to the function of the cerebellum beyond noting it to be an organ of motor control. A historical overview of research on cerebellar function is presented, from pre-Sherrinton suggestions of sensory and motor function, through the post-Sherrinton and dominant 20 th . Century view of "motor" function, to the 21 st . century perspective of "sensorimotor" function. The intrinsic capability of the cerebellum is briefly considered in terms of: its size/complexity/capacity; its information representation/processing characteristics (with "a particular computational function"); its sensory information processing capability; and, its role in sensorimotor regulatory control. It is suggested that the cerebellum can process sensorimotor stimulus information in a statistical (connectionist type) manner and respond to in on the basis of its own learning based sensorimotor representations, albeit at a "level" that does not necessarily involve cerebral "awareness".

Stroke is among the leading causes of long-term disability, leaving an increasing number of people with cognitive and motor impairments, loss of independence in their daily life and with a high societal cost. So far, the development of Brain-Computer Interfaces (BCIs) that translate brain activity into control signals in computers or external devices provide new strategies to overcome stroke-related motor limitations. Recent studies demonstrated the brain's capacity for functional and structural plasticity and recovery even in severe chronic stroke. However, it is not fully clear how we can exploit the neurobiological mechanisms underlying recovery. This is the case for restorative BCI research. There is currently no standardized and accepted treatment for the use of BCIs with patients suffering from acute or chronic motor impairments. In this study we investigated with 9 healthy participants the role of multimodal virtual reality (VR) simulations and motor priming (MP) in a motor imagery BCI training. Our findings show improved BCI performance for VR and MP conditions, as well as the capacity to modulate and enhance brain activity patterns. Our data suggest that both VR and MP can be useful to promote neural activation and neuroplastic changes in the rehabilitation of stroke patients in a motor imagery neurofeedback paradigm.

Stroke is a cardiovascular accident within the brain resulting in motor and sensory impairment in most of the survivors. A stroke can produce complete paralysis of the limb although sensory abilities are normally preserved. Functional electrical stimulation (FES), robotics and brain computer interfaces (BCIs) have been used to induce motor rehabilitation. In this work we measured the brain activity of healthy volunteers using electroencephalography (EEG) during FES, passive movements, active movements, motor imagery of the hand and resting to compare afferent and efferent brain signals produced during these motor related activities and to define possible features for an online FES-BCI. In the conditions in which the hand was moved we limited the movement range in order to control the afferent flow. Although we observed that there is a subject dependent frequency and spatial distribution of efferent and afferent signals, common patterns between conditions and subjects were present ma...

In depression, negative beliefs are coupled with profound physical weakness. Specifically, the belief that one is incapable of altering events in order to prevent expected negative outcomes or bring about positive outcomes leads to bodily symptoms characterized by low energy, slow motor movement, and delays in the initiation of movement. The purpose of this article is to present a theoretical model describing the causal mechanisms that link these cognitive and somatic elements of depression. We propose that (a) the inability to alter events is conceptualized metaphorically as motor incapacity; (b) as part of this conceptualization, the experience of motor incapacity is mentally simulated; and (c) this simulation leads to both subjective feelings of lethargy and peripheral physiological changes consistent with motor incapacity.

The representation of the body in the brain is continuously updated with regard to peripheral factors such as position or movement of body parts. In the present study, we investigated the eVects of arm posture on the mental rotation of hands and feet. Sixteen right-handed and ten left-handed participants verbally judged the laterality of visually presented pictures of hands and feet in two diVerent postural conditions. In one condition they placed their right hand on their right knee and their left hand behind the back, in the other condition the hand position was reversed. For right-handed participants response times for the laterality judgment of right hands increased when participants kept their right hand behind the back. This was not found for images of the left hand nor for images of the feet. For the left-handed participants, there was no eVect of arm posture on hand or feet stimulus judgments. Thus, the body-part posture eVect on mental rotation was found to be speciWc for the side and the body part for which the posture was modiWed only in right-handed participants, but it was absent for left-handed participants. For both samples, we also found a progressive disruption of the mental rotation function depending on the view from which the body parts were seen (i.e. dorsal, thumb/big toe, palm/plantar, little Wnger/toe). Posture and view eVects on body parts representations are discussed with respect to proprioception, handedness, visual familiarity and the inXuence of anatomical joint constraints on motor imagery.

Brain-computer interfaces (BCIs) enable people with paralysis to communicate with their environment. Motor imagery can be used to generate distinct patterns of cortical activation in the electroencephalogram (EEG) and thus control a BCI. To elucidate the cortical correlates of BCI control, users of a sensory motor rhythm (SMR)-BCI were classified according to their BCI control performance. In a second session these participants performed a motor imagery, motor observation and motor execution task in a functional magnetic resonance imaging (fMRI) scanner. Group difference analysis between high and low aptitude BCI users revealed significantly higher activation of the supplementary motor areas (SMA) for the motor imagery and the motor observation tasks in high aptitude users. Low aptitude users showed no activation when observing movement. The number of activated voxels during motor observation was significantly correlated with accuracy in the EEG-BCI task (r = 0.53). Furthermore, the number of activated voxels in the right middle frontal gyrus, an area responsible for processing of movement observation, correlated (r = 0.72) with BCI-performance. This strong correlation highlights the importance of these areas for task monitoring and working memory as task goals have to be activated throughout the BCI session. The ability to regulate behavior and the brain through learning mechanisms involving imagery such as required to control a BCI constitutes the consequence of ideo-motor co-activation of motor brain systems during observation of movements. The results demonstrate that acquisition of a sensorimotor program reflected in SMR-BCI-control is tightly related to the recall of such sensorimotor programs during observation of movements and unrelated to the actual execution of these movement sequences.

Motor imagery is a mental rehearsal of simple or complex motor acts without overt body movement. It has been proposed that the association between performance and the mental rehearsal period that precedes the voluntary movement is an important point of difference between highly trained athletes and beginners. We compared the activation maps of elite archers and nonarchers during mental rehearsal of archery to test whether the neural correlates of elite archers were more focused and efficiently organised than those of nonarchers. Brain activation was measured using functional MRI in 18 right-handed elite archers and 18 right-handed nonarchers. During the active functional MRI imagery task, the participants were instructed to mentally rehearse their archery shooting from a first-person perspective. The active imagery condition was tested against the nonmotor imagery task as a control condition. The results showed that the premotor and supplementary motor areas, and the inferior frontal region, basal ganglia and cerebellum, were active in nonarchers, whereas elite archers showed activation primarily in the supplementary motor areas. In particular, our result of higher cerebellar activity in nonarchers indicates the increased participation of the cerebellum in nonarchers when learning an unfamiliar archery task. Therefore, the difference in cerebellar activation between archers and nonarchers provides evidence of the expertise effect in the mental rehearsal of archery. In conclusion, the relative economy in the cortical processes of elite archers could contribute to greater consistency in performing the specific challenge in which they are highly practised.

This paper supports the contention that the brain stores memories in the form of a central representation that is accessed by both physical preparation and execution and, more importantly, by motor imagery associated with this preparation and execution. Considerable evidence in support of shared central and vegetative structures suggests that sport psychologists should consider more closely aspects of the performer's responses to the physical skill when providing imagery interventions and not rely on "traditional," more clinically orientated, methods of delivery. Many texts provide a schedule of factors and techniques for psychologists, athletes, and coaches to consider but with a limited theoretical explanation of why these factors are the crucial concerns. We, therefore, propose an evidencebased, 7-point checklist that includes: physical, environmental, task, timing, learning, emotional, and perspective elements of imagery delivery highlighting the minimum requirement areas in which sport psychologists should monitor the equivalence to the physical task in order to enhance the efficacy of their practice.

system can selectively attend to the sensorimotor information input that it receives from naturomorphic system The sensorimotor input from the naturomorphic system may be in the form of visuomotor 'imagery' experienced as virtual reality, and it may include 'inner speech' or the 'inner voice'

The purpose of the present study was to investigate the effects on the duration of imagined movements of changes in timing and order of performance of actual and imagined movement. Two groups of subjects had to actually execute and imagine a walking and a writing task. The first group first executed 10 trials of the actual movements (block A) and then imagined the same movements at different intervals: immediately after actual movements (block I-1) and after 25 min (I-2), 50 min (I-3) and 75 min (I-4) interval. The second group first imagined and then actually executed the tasks. The duration of actual and imagined movements, recorded by means of an electronic stopwatch operated by the subjects, was analysed. The duration of imagined movements was very similar to those of actual movements, for both tasks, regardless of either the interval elapsed from the actual movements (first group) or the order of performance (second group). However, the variability of imagined movement duration was significantly increased compared to variability of the actual movements, for both motor tasks and groups. The findings give evidence of similar cognitive processes underlying both imagination and actual performance of movement. #

This paper reviews studies on neurophysiological and behavioral methods used to evaluate motor imagery accuracy. These methods can be used when performed in the field and are based on recordings of peripheral indices such as autonomic nervous system or electromyographic activities, mental chronometry and psychological tests. Providing physiological signs that correlate to these types of mental processes may be considered an objective approach for motor imagery analysis. However, although autonomic nervous system activity recording has been shown to match motor imagery in real time, to evaluate its accuracy qualitatively and the individual ability to form mental images, the relationship between physiological responses and mental processes remains an inference. Moreover, electromyographic recordings may be associated with postural control data, but due to inconsistent results, they remain insufficient to solely evaluate motor imagery accuracy. Other techniques traditionally used in psychology and cognitive psychology are questionnaires, ''debriefing'' with subjects and mental chronometry. Although such methods lead to interesting results, there remains an important part of subjectivity as subjects perform an autoevaluation of motor imagery accuracy. Similarly, mental chronometry gives information on the ability to preserve temporal organization of movement but does not allow the evaluation of the vividness of mental images. Thus, several methods should be combined to analyze motor imagery accuracy in greater detail. Neurophysiological recordings cannot therefore be considered an alternative but rather a complementary technique to behavioral and psychological methods. The advantages and inconvenient of each technique and the hypotheses that could be tested are discussed. D

This paper presents an overview of the key neuroscience studies investigating the neural mechanisms of self-initiated movements that form the basis of our human consciousness. These studies, which commenced with the seminal works of Benjamin Libet and colleagues, showed that an ensemble of brain areas — localized to the frontal and medial regions of the brain — are involved in engendering the conscious decision to commit a motor act. Regardless of differences in neuroimaging techniques, these studies commonly showed that early neuronal activities in the frontal lobules and supplementary motor areas, interpreted by some to be reflective of unconscious processes, occurred before one was conscious of the intention to act as well as the act itself. I examine and discuss these empirical findings with regard to the need to analyze the contents and stages of awareness, and devise paradigm-specific models or theories that could account for inconsistent findings garnered from different experimental paradigms. This paper concludes by emphasizing a need to reconcile the principles of determinism with the notions of free will in future development of consciousness research and theories. © The Institute of Mind and Behavior, Inc., P.O. Box 522, Village Station, New York City, New York, 10014. URL: https://umaine.edu/jmb/

Although several studies have demonstrated that motor imagery can enhance learning processes and improve motor performance, little is known about its effect on stretching and flexibility. The increased active and passive range of motion reported in preliminary research has not been shown to be elicited by motor imagery training alone. We thus compared flexibility scores in 21 synchronized swimmers before and after a 5-week mental practice programme that included five stretching exercises in active and passive conditions. The imagery training programme resulted in selective increased flexibility, independently of the stretching method. Overall, the improvement in flexibility was greater in the imagery group than in the control group for the front split (F 1,18 ¼ 4.9, P ¼ 0.04), the hamstrings (F 1,18 ¼ 5.2, P ¼ 0.035), and the ankle stretching exercises (F 1,18 ¼ 5.6, P ¼ 0.03). There was no difference in shoulders and side-split flexibility (F 1,18 ¼ 0.1, P ¼ 0.73 and F 1,18 ¼ 3.3, P ¼ 0.08 respectively). Finally, there was no correlation between individual imagery ability and improvement in flexibility. Psychological and physiological effects of motor imagery could explain the increase in range of motion, suggesting that imagery enhances joint flexibility during both active and passive stretching.

Skill learning is the improvement in perceptual, cognitive, or motor performance following practice. Expert performance levels can be achieved with well-organized knowledge, using sophisticated and specific mental representations and cognitive processing, applying automatic sequences quickly and efficiently, being able to deal with large amounts of information, and many other challenging task demands and situations that otherwise paralyze the performance of novices. The neural reorganizations that occur with expertise reflect the optimization of the neurocognitive resources to deal with the complex computational load needed to achieve peak performance. As such, capitalizing on neuronal plasticity, brain modifications take place over time-practice and during the consolidation process. One major challenge is to investigate the neural substrates and cognitive mechanisms engaged in expertise, and to define "expertise" from its neural and cognitive underpinnings. Recent insight...

The primary aims of this research were to examine (1) mu and beta event-related desynchronization/ synchronization (ERD/ERS) during motor imagery tasks with varying movement duration and (2) the potential impacts of movement duration on ERD/ERS patterns. Motor imagery tasks included brief and continuous imagined hand movements. During an imagery task, participants imagined an indicated movement for 1 s (i.e., brief movement imagery) or 5 s (i.e., continuous movement imagery). The results of the study support (1) that mu and beta ERD/ERS patterns are elicited during imagined hand movements and (2) that movement duration affects ERS and does not affect ERD patterns, during motor movement imagery. Additionally, brief movement imagery had a greater impact on mu and beta ERD; continuous movement imagery had a greater impact on mu and beta ERS. This research will be useful for designing future brainecomputer interfaces as it provides valuable insight into the dynamics of electroencephalographic (EEG) oscillatory changes during motor imagery tasks with varying movement duration. Relevance to industry: : Brainecomputer interfaces (BCIs) have gained considerable interests by both research and industry communities who want to improve the quality of life for those who suffer from severe motor disabilities, such as amyotrophic lateral sclerosis (ALS), brainstem stroke, and cerebral palsy (CP). The results of this study should be applied to EEG-based BCI system design in order to enhance accuracy and classification performance for BCI system control.

clinicians and researchers together to discuss key issues and future directions related to neural interface technology 4 . This review classifies neural interface devices and systems into two categories, neural recording systems and neural stimulation systems, based on the direction of information flow. Neural recording systems retrieve information from the nervous system through electrophysiological recording methods, such as electroencephalography (EEG) and microelectrode recording of single-neuron activities. Neural stimulation systems feed information into the nervous system by electrically or magnetically activating or inhibiting neural activity. This is a simplified classification scheme, as certain neural interface devices are capable of both neural recording and stimulation, such as implantable responsive neurostimulators for epilepsy treatment 5,6 . As the term neural interface technology covers a broad range of devices and systems, it is a daunting task to provide a detailed and informative discussion on each device and system in one review paper. Furthermore, there exist multiple books, special journal issues, and review papers that are excellent references for neural interface technology 7-15 . Hence, this paper aims to review neural interface technology from three unique perspectives. First, it will focus primarily on neural interface systems that are currently under active research but have not yet reached clinical practice, hoping to illustrate not only where we are, but also where we will be in the near future. Second, this paper will exemplify neural interface technology with systems that the authors have directly worked with in their rehabilitation research and clinical practice to provide a first-hand view of neural interface technology. Last and the most important, this paper will review neural interface technology in association with neuroplasticity, a foundation for neurological rehabilitation, and demonstrate that those two concepts work symbiotically to improve the quality of life for individuals with disabilities, as illustrated in . Neuroplasticity will help those individuals to make better use of their neural interface devices , and neural interface technology can also promote neuroplasticity for functional recovery 7,20 .

Brain-Computer Interfaces (BCIs) have become a large research field that include challenges mainly in neuroscience, signal processing, machine learning and user interface. A non-invasive BCI can allow the direct communication between humans and computers by analyzing electrical brain activity, recorded at the surface of the scalp with electroencephalography. The main purpose for BCIs is to enable communication for people with severe disabilities. Spelling is one of the first BCI application, it corresponds to the main communication mean for people who are unable to speak. While spelling can be the most basic application it remains a benchmark for communication applications and one challenge in the BCI community for some patients. This paper proposes a review of the current main strategies, and their limitations, for spelling words. It includes recent BCIs based on P300, steady-state visual evoked potentials and motor imagery. By considering some challenges in BCI spellers and virtual keyboards, some pragmatic issues are pointed out to eliminate false hopes about BCI for both disabled and healthy people.

Research shows that motor imagery practice (MIP) is effective in enhancing skilled performance both in healthy populations and in clinical groups. Despite such findings, relatively little is known about certain cognitive changes induced by, and/or associated with, MIP. In this opinion piece, we consider four such questions. Firstly, how do participants in MIP studies construct procedural representations from the instructions presented to them in imagery scripts? Secondly, what is known about the interaction between working memory (WM) and MIP? Thirdly, how do cognitive representations of covertly rehearsed skills change during MIP? Finally, what aspects of MI skills change over time as a function of MIP? Before addressing these issues, however, we must consider how MIP effects are typically explained.

Abstract—The electroencephalogram (EEG) is modified by motor imagery and can be used by patients with severe motor impairments (eg, late stage of amyotrophic lateral sclerosis) to communicate with their environment. Such a direct connection between the brain and the computer is ...

While there is ample evidence that motor imagery (MI) may improve motor performance, the models that have been proposed are mainly focused on some of the key components required to ascertain effectiveness, but do not give an extended overview of MI functions. This article reviews the models of greatest conceptual viability, and aims at describing the fields in which MI may play a crucial role, by integrating these functions in a unique model within motor performance and recovery. The detailed description of the imagery-based interventions considers distinct outcomes: (i) motor learning and performance, (ii) motivation, self-confidence and anxiety, (iii) strategies and problem-solving, and (iv) injury rehabilitation. The Motor Imagery Integrative Model of Imagery in Sport (MIIMS) may be used as a global guiding framework in the field of MI studies to develop more effective imagery interventions by covering the major key components of MI training related to the outcome achieved by athletes.

This study examined how imagery ability could affect motor improvement following motor imagery training in tennis . Skilled tennis players were divided into 3 groups with regard to their MIQ scores (good imager, poor imager and control group) . During a pre-test, participants physically performed 15 service returns towards a target . The motor imagery training period was included during physical training for 15 sessions and each session consisted of 2 series of 15 imagined trials and 15 physical trials . Some of the participants were required to use internal visual imagery (good and poor imager groups) while others were given a reading task (control group) . Finally, 48 hours after the last training session, participants were submitted to a post-test similar to the pre-test . Results indicated that motor imagery improved service return, and that this improvement was better in good imagers than in poor imagers . The impact of motor imagery practice on motor performance, for skilled tennis players, is discussed .

The most usually applied therapy for stroke rehabilitation is based on functional task repetition. As an alternative therapy Brain-Computer Interface (BCI) based on motor imagery (MI) are used. This paper presents a BCI system designed and implemented for detecting brain activity related to left/right hand MI. Electroencephalography signal was recorded using EPOC device and it was processed with free software OpenViBE. A control signal that commands a visual application which gives feedback to the subject was generated. Two calibration methods were included: calibration with current information and calibration with prior information. A system's evaluation was conducted on two volunteers without neurological sequelae, for each one of them the accuracy was calculated and a MI index which reflects the subject's ability to imagine movement was estimated. The mean accuracy for daily calibration was 0.59 and for continue calibration was 0.68. The mean MI index for one subject was 0.82 and for the second subject was 0.94. These preliminaries results suggest that the developed system could be used to detect brain activity related to MI.

There is now compelling evidence that motor imagery (MI) and actual movement share common neural substrate. However, the question of how MI inhibits the transmission of motor commands into the efferent pathways in order to prevent any movement is largely unresolved. Similarly, little is known about the nature of the electromyographic activity that is apparent during MI. In addressing these gaps in the literature, the present paper argues that MI includes motor execution commands for muscle contractions which are blocked at some level of the motor system by inhibitory mechanisms. We first assemble data from neuroimaging studies that demonstrate that the neural networks mediating MI and motor performance are not totally overlapping, thereby highlighting potential differences between MI and actual motor execution. We then review MI data indicating the presence of subliminal muscular activity reflecting the intrinsic characteristics of the motor command as well as increased corticomotor excitability. The third section not only considers the inhibitory mechanisms involved during MI but also examines how the brain resolves the problem of issuing the motor command for action while supervising motor inhibition when people engage in voluntary movement during MI.The last part of the paper draws on imagery research in clinical contexts to suggest that some patients move while imagining an action, although they are not aware of such movements. In particular, experimental data from amputees as well as from patients with Parkinson's disease are discussed. We also review recent studies based on comparing brain activity in tetraplegic patients with that from healthy matched controls that provide insights into inhibitory processes during MI. We conclude by arguing that based on available evidence, a multifactorial explanation of motor inhibition during MI is warranted.

Dans le cadre actuel des avancées des neurosciences et de la médecine factuelle, l'imagerie motrice semble une technique prometteuse pour les rééducateurs. Dans cette revue de la
littérature, nous présentons les bases nécessaires à la compréhension et à la mise en place d'un programme d'imagerie. Notre objectif est d'apporter des réponses aux questions suivantes : quelles sont les bases neuroscientifiques de la pratique en imagerie motrice ? Quelles sont les critères de bonnes pratiques et les moyens de les évaluer ? Quelles sont les indications et les contre-indications ? Enfin, nous présenterons des exemples d'applications cliniques. Nous conclurons sur le fait que l'imagerie motrice présente peu de risques ainsi qu'un faible coût. Dans le domaine de la rééducation, recourir à l'imagerie motrice entre donc dans le cadre de la transition actuelle vers des pratiques basées sur les preuves.

This paper investigates the classification of multiclass motor imagery for electroencephalogram (EEG)-based Brain-Computer Interface (BCI) using the Filter Bank Common Spatial Pattern (FBCSP) algorithm. The FBCSP algorithm classifies EEG measurements from features constructed using subject-specific temporal-spatial filters. However, the FBCSP algorithm is limited to binary-class motor imagery. Hence, this paper proposes 3 approaches of multi-class extension to the FBCSP algorithm: One-versus-Rest, Pair-Wise and Divide-and-Conquer. These approaches decompose the multi-class problem into several binary-class problems. The study is conducted on the BCI Competition IV dataset IIa, which comprises single-trial EEG data from 9 subjects performing 4-class motor imagery of left-hand, right-hand, foot and tongue actions. The results showed that the multi-class FBCSP algorithm could extract features that matched neurophysiological knowledge, and yielded the best performance on the evaluation data compared to other international submissions.

A major limitation of current Brain-Computer Interfaces (BCI) based on Motor Imagery (MI) is that they are subject-specific BCI, which require data recording and system training for each new user. This process is time consuming and inconvenient, especially for casual users or portable BCI with limited computational resources. In this paper, we explore the design of a Subject-Independent (SI) MI-based BCI, i.e., a BCI that can be used immediately by any new user without training the BCI with the user's data. This is achieved by training the BCI on data acquired from several other subjects. In order to assess the possibility to build such a BCI, we compared several designs based on different features and classifiers, on data from 9 subjects. Our results suggested that linear classifiers were the most appropriate for the design of MIbased SI-BCI. We also proposed a filter bank common spatial patterns feature extraction method based on a multi-resolution frequency decomposition which achieved the highest accuracy.

La disabilità motoria è una conseguenza frequente ed invalidante nei pazienti post-ictus e ruolo fondamentale della riabilitazione è la riacquisizione del controllo motorio. Il recupero funzionale è strettamente legato a fenomeni di riorganizzazione cerebrale e plasticità neuronale. L'efficienza e la velocità del recupero motorio dipendono anche dalla disponibilità di informazioni sensoriali di natura propriocettiva, tattile, vestibolare, visiva e uditiva. Molti Autori ritengono che anche l'immaginazione e l'osservazione possano giocare un ruolo nel processo di riapprendimento. È stato dimostrato che il sistema motorio è attivato sia durante l'esecuzione del gesto, sia durante l'osservazione (motor observation) e l'immaginazione del movimento (motor imagery). La prima evidenza dell'esistenza di un circuito Mirror risale agli studi condotti con EEG nel 1950 da Gastaut e a quelli condotti nel 1982 da Hyvarinen sul lobo parietale posteriore ma certamente la scoperta vera e propria dei neuroni mirror si deve a Rizzolatti e coll. nel 1996. I neuroni mirror sono una particolare classe di neuroni visuo-motori, originariamente scoperti nell'area F5 della corteccia premotoria del macaco, che si attivano sia quando la scimmia compie una determinata azione e sia quando osserva un altro individuo (scimmia o uomo) compiere una simile azione. Tali neuroni sono presenti anche nell'uomo nella corteccia pre-frontale, nella corteccia pre-motoria, nell'area motoria supplementare, nella corteccia del cingolo, nella corteccia parietale e nel cervelletto ( ). La scoperta dei neuroni mirror dimostra che il sistema motorio può essere attivato sia in una condizione "on line" durante l'esecuzione del gesto, sia in una condizione "off line" durante l'osservazione o l'immaginazione di un atto che rientri nel repertorio motorio del soggetto che osserva.

The brain plays a key role in CRPS. A widely-­‐studied brain region in pain research is the primary somatosensory cortex (S1), a somatotopic map of our body’s surface which funcEonally reorganises in pain [1]. Changes in the S1 representaEon of the CRPS-­‐affected body part have contributed to new CRPS treatments, e.g. graded motor imagery. This systemaEc review and meta-­‐analysis aimed to determine whether CRPS is associated with: a) a change in the size of the S1 representaEon of the affected body part; b) altered S1 acEvity, in terms of acEvaEon levels and latency of responses.

As shows, a noninvasive BCI system captures brain signals through the EEG, extracts and classifies certain signal features, and feeds them to the application. New uses of noninvasive BCI systems are continu-BCi systems let users convert thoughts into actions that do not involve voluntary muscle movement. the systems offer a new means of communication for those with paralysis or severe neuromuscular disorders.

This study compares the improvement and generalization of arm motor performance after physical or mental training in a motor task requiring a speed-accuracy tradeoff. During the pre-and post-training sessions, 40 subjects pointed with their right arm as accurately and as fast as possible toward targets placed in the frontal plane. Arm movements were performed in two different workspaces called right and left paths. During the training sessions, which included only the right path, subjects were divided into four training groups (n‫:)01؍‬ (i) the physical group, subjects overtly performed the task; (ii) the mental group, subjects imagined themselves performing the task; (iii) the active control group, subjects performed eye movements through the targets, (iv) the passive control group, subjects did not receive any specific training. We recorded movement duration, peak acceleration and electromyographic signals from arm muscles. Our findings showed that after both physical and mental training on the right path (training path), hand movement duration and peak acceleration respectively decreased and increased for this path. However, motor performance improvement was greater after physical compared with mental practice. Interestingly, we also observed a partial learning generalization, namely an enhancement of motor performance for the left path (non-training path). The amount of this generalization was roughly similar for the physical and mental groups. Furthermore, while arm muscle activity progressively increased during the training period for the physical group, the activity of the same muscles for the mental group was unchanged and comparable with that of the rest condition. Control groups did not exhibit any improvement. These findings put forward the idea that mental training facilitates motor learning and allows its partial transfer to nearby workspaces. They further suggest that motor prediction, a common process during both actual and imagined movements, is a fundamental operation for both sensorimotor control and learning.

Polyphonic music combines multiple auditory streams to create complex auditory scenes, thus providing a tool for investigating the neural mechanisms for orienting attention in natural auditory contexts. Across two fMRI experiments, we varied stimuli and task demands in order to identify cortical areas that are activated during attentive listening to real music. In individual experiments and in a conjunction analysis of the two experiments, we found bilateral blood oxygen level dependent (BOLD) signal increases in temporal (superior temporal gyrus), parietal (intraparietal sulcus) and frontal areas (precentral sulcus, inferior frontal sulcus and gyrus, frontal operculum) during selective and global listening compared to passive rest without musical stimulation. Direct comparisons of the listening conditions showed significant differences between attending to single timbres (instruments) and attending across multiple instruments, though the patterns that were observed depended on the relative demands of the tasks being compared. The overall pattern of BOLD signal increases indicated that attentive listening to music recruits neural circuits underlying multiple forms of working memory, attention, semantic processing, target detection, and motor imagery. Thus, attentive listening to music appears to be enabled by areas that serve general functions rather than by "musicspecific" cortical modules.

Previous research suggests that conversion disordered patients with hand/am paralysis exhibit slowed reaction times for mental hand-rotation tasks that correspond to their affected arm when the tasks are explicitly instructed and not when they are implicitly cued. Because of the many similarities between hypnotic phenomena and conversion symptoms, the authors tested whether simiiar motor imagery impairment would occur among normal high hypnotizable subjects when paralysis is suggested. Nine high and 8 low hypnotizable subjects were administered an implicit and an explicit mental hand-rotation task during hypnotically suggested paralysis of the right arm. On the implicit task, there were no significant reaction time (RT) differences between highs and lows. On the explicit task, only highs showed a significantly larger RT increase per degree of rotation with the paralyzed arm, compared to the normal arm. These preliminary findings suggest that the motor imagery impairment observed in conversion paralysis can be induced in highs using hypnosis.