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Brain–computer interface (BCI) is a promising technique that enables patients' interaction with computers or machines by analyzing specific brain signal patterns and provides patients with brain state-dependent feedback to assist in their rehabilitation. Action observation (AO) and peripheral electrical stimulation (PES) are conventional methods used to enhance rehabilitation outcomes by promoting neural plasticity. In this study, we assessed the effects of attentional state-dependent feedback in the combined application of BCI-AO with PES on sensorimotor cortical activation in patients after stroke. Our approach involved showing the participants a video with repetitive grasping actions under four different tasks. A mu band suppression (8–13 Hz) corresponding to each task was computed. A topographical representation showed that mu suppression of the dominant (healthy) and affected hemispheres (stroke) gradually became prominent during the tasks. There were significant differences in mu suppression in the affected motor and frontal cortices of the stroke patients. The involvement of both frontal and motor cortices became prominent in the BCI-AO+triggered PES task, in which feedback was given to the patients according to their attentive watching. Our findings suggest that synchronous stimulation according to patient attention is important for neurorehabilitation of stroke patients, which can be achieved with the combination of BCI-AO feedback with PES. BCI-AO feedback combined with PES could be effective in facilitating sensorimotor cortical activation in the affected hemispheres of stroke patients. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of electronic stimulation (ES) as a non-pharmacological treatment in restless legs syndrome (RLS). This is a randomized, single-blind study. A total of 46 patients were included, consisting of an active group and a sham group with 22 and 24 members, respectively. The stimulation was administered to bilateral lower legs using the tapping mode (3 Hz) on a handheld ES device, and symptom changes were measured in both groups. The effects of the stimuli were analyzed with repeated measures ANOVA. The symptom severity was significantly reduced in the active group, and showed significant interaction effects in the time * group (F = 4.441, p = 0.031). Although both the active and sham groups reported improved symptoms upon receiving longer periods of treatment, the effect of the ES was greater in the active group. ES treatment resulted in symptom improvement when using ideal levels of stimulation intensity. ES can be considered as a non-pharmacological treatment option for RLS. [ABSTRACT FROM AUTHOR]

Keeping patients from being distracted while performing motor rehabilitation is important. An EEG-based biofeedback strategy has been introduced to help encourage participants to focus their attention on rehabilitation tasks. Here, we suggest a BCI-based monitoring method using a flickering cursor and target that can evoke a steady-state visually evoked potential (SSVEP) using the fact that the SSVEP is modulated by a patient’s attention. Fifteen healthy individuals performed a tracking task where the target and cursor flickered. There were two tracking sessions, one with and one without flickering stimuli, and each session had four conditions in which each had no distractor (non-D), a visual (vis-D) or cognitive distractor (cog-D), and both distractors (both-D). An EEGNet was trained as a classifier using only non-D and both-D conditions to classify whether it was distracted and validated with a leave-one-subject-out scheme. The results reveal that the proposed classifier demonstrates superior performance when using data from the task with the flickering stimuli compared to the case without the flickering stimuli. Furthermore, the observed classification likelihood was between those corresponding to the non-D and both-D when using the trained EEGNet. This suggests that the classifier trained for the two conditions could also be used to measure the level of distraction by windowing and averaging the outcomes. Therefore, the proposed method is advantageous because it can reveal a robust and continuous level of patient distraction. This facilitates its successful application to the rehabilitation systems that use computerized technology, such as virtual reality to encourage patient engagement. [ABSTRACT FROM AUTHOR]

Dysfunctional emotional processing affects social functioning in patients with schizophrenia. However, the relationship between emotional perception and response in social interaction has not been elucidated. Twenty-seven patients with schizophrenia and 27 normal controls performed a virtual reality social encounter task in which they introduced themselves to avatars expressing happy, neutral, or angry emotions while verbal response duration and onset time were measured and perception of emotional valence and arousal, and state anxiety were rated afterwards. Self-reported trait-affective scale scores and the Positive and Negative Syndrome Scale (PANSS) ratings were also obtained. Patient group significantly underestimated the valence and arousal of angry emotions expressed by an avatar. While valence and arousal ratings of happy avatars were comparable between groups, patient group reported significantly higher state anxiety in response to happy avatars. State anxiety ratings significantly decreased from encounters with neutral to happy avatars in normal controls while no significant decrease was observed in the patient group. The Social Anhedonia Scale and PANSS negative symptom subscale scores (blunted affect, emotional withdrawal, and passive/ apathetic social withdrawal items) were significantly correlated with state anxiety ratings of the encounters with happy avatars. These results suggest that patients with schizophrenia have interference with the experience of pleasure in social interactions which may be associated with negative symptoms.

Action observation (AO) is a promising strategy for promoting motor function in neural rehabilitation. Recently, brain–computer interface (BCI)-AO game rehabilitation, which combines AO therapy with BCI technology, has been introduced to improve the effectiveness of rehabilitation. This approach can improve motor learning by providing feedback, which can be interactive in an observation task, and the game contents of the BCI-AO game paradigm can affect rehabilitation. In this study, the effects of congruent rather than incongruent feedback in a BCI-AO game on mirror neurons were investigated. Specifically, the mu suppression with congruent and incongruent BCI-AO games was measured in 17 healthy adults. The mu suppression in the central motor cortex was significantly higher with the congruent BCI-AO game than with the incongruent one. In addition, the satisfaction evaluation results were excellent for the congruent case. These results support the fact that providing feedback congruent with the motion of an action video facilitates mirror neuron activity and can offer useful guidelines for the design of BCI-AO games for rehabilitation. [ABSTRACT FROM AUTHOR]

Abstract Background Several experimental studies in stroke patients suggest that mirror therapy and various virtual reality programs facilitate motor rehabilitation. However, the underlying mechanisms for these therapeutic effects have not been previously described. Objectives We attempted to delineate the changes in corticospinal excitability when individuals were asked to exercise their upper extremity using a real mirror and virtual mirror. Moreover, we attempted to delineate the role of visual modulation within the virtual environment that affected corticospinal excitability in healthy subjects and stroke patients. Methods A total of 18 healthy subjects and 18 hemiplegic patients were enrolled into the study. Motor evoked potential (MEP)s from transcranial magnetic stimulation were recorded in the flexor carpi radialis of the non-dominant or affected upper extremity using three different conditions: (A) relaxation; (B) real mirror; and (C) virtual mirror. Moreover, we compared the MEPs from the virtual mirror paradigm using continuous visual feedback or intermittent visual feedback. Results The rates of amplitude increment and latency decrement of MEPs in both groups were higher during the virtual mirror task than during the real mirror. In healthy subjects and stroke patients, the virtual mirror task with intermittent visual feedback significantly facilitated corticospinal excitability of MEPs compared with continuous visual feedback. Conclusion Corticospinal excitability was facilitated to a greater extent in the virtual mirror paradigm than in the real mirror and in intermittent visual feedback than in the continuous visual feedback, in both groups. This provides neurophysiological evidence supporting the application of the virtual mirror paradigm using various visual modulation technologies to upper extremity rehabilitation in stroke patients.

Virtual reality (VR) is effectively used to evoke the mirror illusion, and transcranial direct current stimulation (tDCS) synergistically facilitates this illusion. This study investigated whether a mirror virtual hand illusion (MVHI) induced by an immersive, first-person-perspective, virtual mirror system could be modulated by tDCS of the primary motor cortex. Fourteen healthy adults (average age 21.86 years ±0.47, seven men and seven women) participated in this study, and they experienced VR with and without tDCS—the tDCS and sham conditions, each of which takes ∼30 minutes—on separate days to allow the washout of the tDCS effect. While experiencing VR, the movements of the virtual left hand reflected the flexion and extension of the real right hand. Subsequently, electroencephalogram was recorded, the magnitude of the proprioceptive shift was measured, and the participants provided responses to a questionnaire regarding hand ownership. A significant difference in the proprioceptive shift was observed between the tDCS and sham conditions. In addition, there was significant suppression of the mu power in Pz, and augmentation of the beta power in the Pz, P4, O1, and O2 channels. The difference in proprioceptive deviation between the two conditions showed significant negative correlation with mu suppression over the left frontal lobe in the tDCS condition. Finally, the question "I felt that the virtual hand was my own hand" received a significantly higher score under the tDCS condition. In short, applying tDCS over the motor cortex facilitates the MVHI by activating the attentional network over the parietal and frontal lobes such that the MVHI induces more proprioceptive drift, which suggests that the combination of VR and tDCS can enhance the immersive effect in VR. This result provides better support for the use of the MVHI paradigm in combination with tDCS for recovery from illnesses such as stroke. [ABSTRACT FROM AUTHOR]

Objectives: Resting-state brain connectivity has been shown to differ for Restless Legs Syndrome (RLS) compared to healthy control (CON) groups. This study evaluates the degree these RLS-CON differences are changed by concurrent treatment.Methods: Resting-state functional MRIs were obtained from 32 idiopathic RLS patients during the morning asymptomatic period and 16 age and gender-matched CON subjects. Of the 32 RLS patients, 16 were drug-naïve (DN-RLS), and 16 were regularly drug-treated using a dopamine agonist (DT-RLS). Various assessments of disease characteristics were also performed. The primary purpose was to assess the replicability of prior results and the effects of treatment on these differences between controls and untreated RLS patients. Resting-state connectivity was analyzed by a seed-based method using the bilateral ventral-posterolateral nuclei (VPLN) in the thalamus.Results: In the DN-RLS group, compared to the CON group, three areas (the bilateral lingual gyri and right middle temporal gyrus) were replicated. The three replicated areas did not significantly differ for DT-RLS compared to DN-RLS. DT-RLS compared to DN-RLS had significantly higher thalamic connectivity for the left uvula, right tuber, left anterior insula, and right declive.Conclusions: Thalamic connectivity to the bilateral lingual gyri and right middle temporal gyrus is a replicable finding in DN-RLS that was not affected by dopamine agonist treatments. Other changes in thalamic connectivity were altered by dopamine agonist treatment. These treatment effects may be pertinent to the known treatment benefits of a dopamine agonist on RLS symptoms. [ABSTRACT FROM AUTHOR]

Highlights • The flickering action video with only single frequency evokes both SSVEP and the mirror neuron system simultaneously. • The mirror neuron system could be differently activated according to the contents of the flickering action video. • Our paradigm could successfully classify the LEFT, RIGHT and rest according to the contents of the flickering action video. • This paradigm has advantages in terms of the classification accuracy and the number of commands using a single frequency. • It provides potential effective BCI rehabilitation applications for people who require BCI control and MNS activation. Abstract Background The number of commands in a brain–computer interface (BCI) system is important. This study proposes a new BCI technique to increase the number of commands in a single BCI system without loss of accuracy. New method We expected that a flickering action video with left and right elbow movements could simultaneously activate the different pattern of event-related desynchronization (ERD) according to the video contents (e.g., left or right) and steady-state visually evoked potential (SSVEP). The classification accuracy to discriminate left, right, and rest states was compared under the three following feature combinations: SSVEP power (19–21 Hz), Mu power (8–13 Hz), and simultaneous SSVEP and Mu power. Results The SSVEP feature could discriminate the stimulus condition, regardless of left or right, from the rest condition, while the Mu feature discriminated left or right, but was relatively poor in discriminating stimulus from rest. However, combining the SSVEP and Mu features, which were evoked by the stimulus with a single frequency, showed superior performance for discriminating all the stimuli among rest, left, or right. Comparison with the existing method The video contents could activate the ERD differently, and the flickering component increased its accuracy, such that it revealed a better performance to discriminate when considering together. Conclusions This paradigm showed possibility of increasing performance in terms of accuracy and number of commands with a single frequency by applying flickering action video paradigm and applicability to rehabilitation systems used by patients to facilitate their mirror neuron systems while training. [ABSTRACT FROM AUTHOR]

We attempted to evaluate the clinical efficiency of a novel three-dimensional interactive augmented reality system (3D-ARS) for balance and mobility rehabilitation. This system enables participant training with a realistic 3D interactive balance exercise and assessing movement parameters and joint angles by using a kinetic sensor system. We performed a randomized controlled trial in a general hospital. Thirty-six participants (age, 56–76 years) who could independently walk and stand on one leg were recruited. The participants were randomly assigned to either group. The control group (n = 18) underwent a conventional physical fitness program such as lower-extremity strengthening and balance training thrice per week for 1 month. The experimental group (n = 18) experienced 3D-ARS training thrice per week (1 session = 30 minutes) for 4 weeks. Training comprised a balloon game for hip exercise, cave game for knee exercise, and rhythm game for one-leg balance exercise. Lower-extremity clinical scale scores, fall index, and automatic balance score were measured by using Tetrax® posturography before, during, and after training. Significant group (3D-ARS vs. control) × time (before and after exercise) interaction effect was observed for Berg balance scale (BBS) scores (p = 0.04) and timed-up-and-go (TUG; p < 0.001). Overall improvements occurred in stability index, weight distribution index, fall risk index, and Fourier transformations index of posturography for both groups. However, score changes were significantly greater in the 3D-ARS group. Significant group × time interaction effect was observed for the fall risk index. This demonstrates that the 3D-ARS system can improve balance in the elderly more effectively. [ABSTRACT FROM AUTHOR]

Action observation training based on the theory of activation of the mirror-neuron system has been used for the rehabilitation of patients with stroke. In this paper, we sought to assess whether a brain–computer interface (BCI)-based action observation rehabilitation game, using a flickering action video, could preferentially activate the mirror-neuron system. Feedback of stimulus observation, evoked by the flickering action video, was provided using steady state visually evoked potential and event-related desynchronization. Fifteen healthy subjects have experienced the game with BCI interaction (game and interaction), without BCI interaction (game without interaction), observed non-flickering stimuli, and flickering stimuli without the game background (stimuli only) in a counter-balanced order. The game and interface condition was resulted in significantly stronger activation of the mirror-neuron system than did the other three conditions. In addition, the amount of mirror-neuron system activation is gradually decreased in the game without interface, non-flickering stimuli, and stimuli only conditions in a time-dependent manner; however, in the game and interface condition, the amount of mirror-neuron system activation was maintained until the end of the training. Taken together, these data suggest that the proposed game paradigm, which integrates the action observation paradigm with BCI technology, could provide interactive responses for whether watching video clips can engage patients and enhance rehabilitation. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effectiveness of the mobile game-based neuromuscular electrical stimulation (MG-NMES) with assessing usability issues, such as attention and curiosity, and intrinsically interesting issues, which is necessary for successful poststroke rehabilitation. With the conventional NMES (C-NMES) system, the subjects underwent active repetitive cyclic NMES training. For assessment of usability issues, 20 hemiplegic stroke subjects were randomly divided into two groups. The subjects in the MG-NMES group (n = 9) and C-NMES group (n = 11) underwent 20 minutes of training each day for 5 days. We assessed the subjects' attention, curiosity, and intrinsically interesting issues; and using questionnaires they answered questions regarding their expectations of the training outcome after each training session. We found that the subjects in the MG-NMES group maintained their attention and interest for the 5 days, and their curiosity and expectation of a positive training outcome gradually increased as the training proceeded. In contrast, the C-NMES group reported no change in their attention or curiosity, but it was lower than the subjects in the MG-NMES group. In addition, their interest gradually decreased, which may have reduced their expectations of a positive outcome as the sessions progressed. There were no side effects during the training sessions in either group. The MG-NMES training paradigm developed is a new, readily available, and highly motivating MG-NMES training system. Based on the usability test, the reported advantages of the system were improved attention and flow experience during NMES training. [ABSTRACT FROM AUTHOR]

Goal: Micromagnetic stimulation using coils sufficiently small to be implanted has been suggested as a potential method to overcome the limitations of electrical stimulation. We investigated the temperature increases in the brain implanted with planar coils. Methods: We conducted computational simulations on the thermal effects of implantable magnetic stimulation in a brain model using finite-element analysis, by varying geometric parameters of planar spiral coils, and repetitive stimulation pulse patterns. Results: It was revealed that the temperature increase in the brain can be controlled by a careful design of coils to implant. The coil diameter greater than 8 mm was required to induce a temperature rise in the brain of less than 1 °C. If the coil diameter was larger than 10 mm, the subsequent temperature rises in the brain tissue was maintained consistently at about 0.24 °C or lower. Conclusion: Selection of the number of coil turns must rely on tradeoffs between the required current and voltage that the implanted source can generate, as the required voltage increases while the required current decreases with increasing number of coil turns. Additionally, the coil insulation with a thickness of a few micrometers was found to suppress the temperature rise in the brain effectively. Significance: Although these simulations employed only one threshold value of 10 V/m, which is rather on the lower end of stimulation threshold, the simulation results are expected to serve as guidelines for designing planar coils to be implanted in the brain for magnetic stimulation. [ABSTRACT FROM PUBLISHER]

ABSTRACT The hippocampus plays a key role in the encoding and retrieval of information related to novel environments during spatial navigation. However, the neural basis for these processes in the human hippocampus remains unknown because it is difficult to directly measure neural signals in the human hippocampus. This study investigated hippocampal neural oscillations involved in encoding novel environments during spatial navigation in a virtual environment. Seven epileptic patients with implanted intracranial hippocampal depth electrodes performed three sessions of virtual environment navigation. Each session consisted of a navigation task and a location-recall task. The navigation task consisted of eight blocks, and in each block, the participant navigated to the location of four different objects and was instructed to remember the location of the objects. After the eight blocks were completed, a location-recall task was performed for each of the four objects. Intracranial electroencephalography data were monitored during the navigation tasks. Theta (5-8 Hz) and delta (1-4 Hz) oscillations were lower in the first block (novel environment) than in the eighth block (familiar environment) of the navigation task, and significantly increased from block one to block eight. By contrast, low-gamma (31-50 Hz) oscillations were higher in the first block than in the eighth block of the navigation task, and significantly decreased from block one to block eight. Comparison of sessions with high recall performance (low error between identified and actual object location) and low recall performance revealed that high-gamma (51-100 Hz) oscillations significantly decreased from block one to block eight only in sessions with high recall performance. These findings suggest that delta, theta, and low-gamma oscillations were associated with encoding of environmental novelty and high-gamma oscillations were important for the successful encoding of environmental novelty. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Objectives. Anhedonia in schizophrenia results from a deficit in anticipatory pleasure rather than consummatory pleasure. This study aimed to determine the neural basis of the predictive and experiential components of anticipatory pleasure in schizophrenia. Methods. A hedonic rating task was performed by 15 patients with schizophrenia and 17 controls while undergoing functional magnetic resonance imaging. Participants evaluated the level of pleasantness for the preview/predictive phase, comprising a narration and adjunctive audiovisual stimuli for pleasurable experience, and the subsequent viewing/experiential phase, comprising a video clip for a pleasant event. Results. A significant group-by-phase interaction was seen in the rostral anterior cingulate cortex (ACC) and caudate, resulting from reduced activations in patients during the preview phase. Patients showed significantly reduced activation in the frontopolar cortex and rostral ACC during the preview phase. The signal changes in the caudate and frontopolar cortex were associated with increase in hedonic response during the sequential pleasure experiences. Conclusions. Augmentation of hedonic enjoyment between the predictive and experiential stages of anticipatory pleasure is reduced in schizophrenia because of diminished activity in the reward-related regions during the prediction of pleasure. During cued-emotional experiences of anticipatory pleasure, patients seem to have difficulties in the integration of emotional information. [ABSTRACT FROM AUTHOR]

Patients with schizophrenia often show abnormal social interactions, which may explain their social exclusion behaviors. This study aimed to elucidate patients’ brain responses to social rejection in an interactive situation. Fifteen patients with schizophrenia and 16 healthy controls participated in the functional magnetic resonance imaging experiment with the virtual handshake task, in which socially interacting contents such as acceptance and refusal of handshaking were implemented. Responses to the refusal versus acceptance conditions were evaluated and compared between the two groups. Controls revealed higher activity in the refusal condition compared to the acceptance condition in the right superior temporal sulcus, whereas patients showed higher activity in the prefrontal regions, including the frontopolar cortex. In patients, contrast activities of the right superior temporal sulcus were inversely correlated with the severity of schizophrenic symptoms, whereas contrast activities of the left frontopolar cortex were positively correlated with the current anxiety scores. The superior temporal sulcus hypoactivity and frontopolar hyperactivity of patients with schizophrenia in social rejection situations may suggest the presence of mentalizing deficits in negative social situations and inefficient processes of socially aberrant stimuli, respectively. These abnormalities may be one of the neural bases of distorted or paranoid beliefs in schizophrenia. [ABSTRACT FROM AUTHOR]

Aim Attention deficit has been reported in both schizophrenia patients and patients with major depressive disorder (MDD). The aim of this study was to elucidate the deficits in sustained attention and associated neural network dysfunctions in schizophrenia patients and MDD patients, and to investigate the difference between the two patient groups. Methods Twelve schizophrenia patients, 12 patients with non-psychotic MDD, and 12 healthy control subjects participated in this study. A sustained attention to response task ( SART) was used to measure attention capacity. Cerebral blood flow ( CBF) during attention tasks was measured using H215O positron emission tomography. Statistical parametric mapping and analysis of covariance were performed to compare the behavioral performance and CBF changes during SART among three groups. Results Behavioral performances were not significantly different among the three groups except for an increased commission error rate in the schizophrenia group. Regional CBF during SART was significantly reduced in the left inferior frontal gyrus, the left cuneus, and the right superior parietal lobule and increased in the right superior frontal gyrus and the right cuneus in the schizophrenia group compared to the healthy control group. In the MDD group, neither significant regional CBF difference nor behavioral deficit was found compared to the healthy control group. Conclusion Behavioral performance deficit and perfusion changes in the prefrontal and parietal cortices during SART were observed only in the schizophrenia group. Prefrontal and parietal network dysfunction for sustained attention may be involved in the pathophysiology of schizophrenia. [ABSTRACT FROM AUTHOR]

Background: Auditory hallucinations often influence schizophrenia patients in many aspects. In order to develop effective behavioral interventions for overcoming enduring auditory hallucinations, it is necessary to understand how the annoying symptom affects the daily lives of the patients. This study evaluated the effect of hearing unusual voices on performing the activities of daily life in schizophrenia patients. Methods: Eighteen hallucinating patients, 18 nonhallucinating patients and 20 normal controls performed the virtual daily-life task of packing 8 items for travel under 3 conditions: (1) without unusual voices and without avatars, (2) with unusual voices and without avatars and (3) with unusual voices and with avatars. Task completion time and the number of times the packing list was checked were recorded as a measure of the task performance. Results: When exposed to unusual voices without avatars, hallucinating patients checked the packing list fewer times than nonhallucinating patients, and they required longer to complete the task, as positive and negative symptoms were worse. Subjective responses to unusual voices were stronger in hallucinating patients than in nonhallucinating patients. Conclusions: Daily-life activities of hallucinating patients may be less easily influenced by odd auditory stimuli in a nonsocial situation than those of nonhallucinating patients; however, hallucinating patients may feel more strongly affected by unusual voices. To better evaluate and thereby understand the difficulties faced by hallucinating patients in their daily life, the discrepancies between objective and subjective measures as well as social situations should be taken into consideration. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]