1,721,292 research outputs found
Simultaneous recording of slow brain potentials and transcranial magnetic stimulation of hand area in human motor cortex
No full textComparison of movement related cortical potential in healthy people and amyotrophic lateral sclerosis patients
No full textObjective: To understand the brain motor functions and neurophysiological changes due to motor disorder by comparing electroencephalographic data between healthy people and amyotrophic lateral sclerosis (ALS) patients. Methods: The movement related cortical potential (MRCP) was recorded from seven healthy subjects and four ALS patients. They were asked to imagine right wrist extension at two speeds (fast and slow). The peak negativity (RN) and rebound rate (RR) were extracted from MRCP for comparison. Results: The statistical analysis has showed that there was no significant difference in RN between the healthy and the ALS subjects. However, the healthy subjects presented faster RR than ALS during both fast and slow movement imagination. Conclusions: The weaker RR of ALS patients might reflect the impairment of motor output pathways or the degree of motor degeneration. Significance: The comparison between healthy people and ALS patients provides a way to explain the movement disorder through brain electrical signal. In addition, the characteristics of MRCP could be used to monitor and guide brain plasticity in patients
An EEG/EOG-based hybrid brain-neural computer interaction (BNCI) system to control an exoskeleton for the paralyzed hand
No full textThe loss of hand function can result in severe physical and psychosocial impairment. Thus, compensation of a lost hand function using assistive robotics that can be operated in daily life is very desirable. However, versatile, intuitive, and reliable control of assistive robotics is still an unsolved challenge. Here, we introduce a novel brain/neural-computer interaction (BNCI) system that integrates electroencephalography (EEG) and electrooculography (EOG) to improve control of assistive robotics in daily life environments. To evaluate the applicability and performance of this hybrid approach, five healthy volunteers (HV) (four men, average age 26.5 ± 3.8 years) and a 34-year-old patient with complete finger paralysis due to a brachial plexus injury (BPI) used EEG (condition 1) and EEG/EOG (condition 2) to control grasping motions of a hand exoskeleton. All participants were able to control the BNCI system (BNCI control performance HV: 70.24 ± 16.71%, BPI: 65.93 ± 24.27%), but inclusion of EOG significantly improved performance across all participants (HV: 80.65 ± 11.28, BPI: 76.03 ± 18.32%). This suggests that hybrid BNCI systems can achieve substantially better control over assistive devices, e.g., a hand exoskeleton, than systems using brain signals alone and thus may increase applicability of brain-controlled assistive devices in daily life environments
Multimodal Investigation on Spatial Attention Mechanisms: A Model of Shared Attention Resources (ShAR)
No full textBirbaumer, Niels Lancioni, Giulio Raffone, Antonin
Brain self-regulation in criminal psychopaths
Full text linkPsychopathic individuals are characterized by impaired affective processing, impulsivity, sensation-seeking, poor planning skills and heightened aggressiveness with poor self-regulation. Based on brain self-regulation studies using neurofeedback of Slow Cortical Potentials (SCPs) in disorders associated with a dysregulation of cortical activity thresholds and evidence of deficient cortical functioning in psychopathy, a neurobiological approach seems to be promising in the treatment of psychopathy. The results of our intensive brain regulation intervention demonstrate, that psychopathic offenders are able to gain control of their brain excitability over fronto-central brain areas. After SCP self-regulation training, we observed reduced aggression, impulsivity and behavioral approach tendencies, as well as improvements in behavioral-inhibition and increased cortical sensitivity for error-processing. This study demonstrates improvements on the neurophysiological, behavioral and subjective level in severe psychopathic offenders after SCP-neurofeedback training and could constitute a novel neurobiologically-based treatment for a seemingly change-resistant group of criminal psychopaths
Neural correlates during mental training of motor execution : a comparison between professional musicians and amateurs
No full textIn dieser Studie wurden die unterschiedlichen fMRI Aktivierungen kortikaler und subkortikaler Areale von professionellen Geigern und Amateuren während mentalen Trainings einer Finger-Tapping-Sequenz untersucht, die den ersten 16 Takten des Soloparts aus Mozarts Violinkonzert in G-Dur entsprach. Da bei professionellen Geigern wegen ihres langjährigen Trainings und ihrer Erfahrung im mentalen Training eine andere kortikale Repräsentation der Bewegungsmuster vorausgesetzt werden kann, wurde angenommen, dass sich ihre Aktivierungsmuster von denen der Amateure unterscheiden. Um sicher zu gehen, dass die Finger nicht bewegt wurden, wurde vor und während der Messung ein Elektromyogramm der Unterarmmuskulatur beider Arme abgeleitet.
Die Vorstellungsaufgabe zeigte in beiden Gruppen eine Erhöhung der kortikalen Aktivierung in supplementär- und prämotorischen, lateralen zerebellären, superior parietalen Regionen. Bei den Profis zeigten sich wenige fokussierte Areale, die insgesamt einem Zugriff auf erlernte und automatisierte Bewegungsprogramme entsprachen (linker PMC, SMA, linkes posteriores Zerebellum, bilateral superior und links inferior parietal, rechts superior frontal, links anterior temporal). Langjähriges musikalisches motorisches Training sowie Erfahrung im mentalen Training gehen anscheinend mit erhöhter neuronaler Effizienz einher. Die Amateure hingegen zeigten weit verstreute Aktivierungen in Arealen, die beim Erlernen neuer Bewegungen beschrieben werden als auch in Regionen, denen sprachliche und visuelle Funktionen zugeschrieben werden (linker PMC und SMA; bilateral sensomotorisch; bilateral posterior zerebellär, bilateral posterior und inferior parietal, operkulär und dorsolateral frontal, links temporal anterior, Nukleus Caudatus). Zusammenfassend lässt sich sagen, dass die aktivierten Regionen der Amateure mit Aktivierungskarten wenig trainierter motorischer Leistung übereinstimmen und dass die neuronale Kapazität gegenüber der der Profis weniger ökonomisch genutzt war. Die aktivierten Areale der Profis hingegen beschreiben einen Abstraktionsprozess während des mentalen Trainings, dessen neuronale Korrelate in der Aktivierung sekundärer und tertiärer motorische Areale bestehen.This study aimed to investigate how imagined motor performance in professional violinists (cf. amateurs) might be manifested in fMRI BOLD signals and whether differential BOLD signals observed in professional and amateur violinists allow additional insights to changes in neural activity with continued motor training. We compared activation maps of professional and amateur violinists during imagination of (left hand) fingering movements of the first 16 bars of Mozart's violin concerto in G major (KV216). Electromyography (EMG) feedback was used during imagery training to avoid actual movement execution.
There is clear evidence of different brain activations in the two groups of musicians during imagined performances: Professionals demonstrated more focused, amateurs scattered activation patterns. In direct comparison, professionals recruited very few cerebral areas, whereas amateurs again manifested a widely distributed activation map. Whereas many cortical areas exhibited increased activity during imagined movement in the amateur group compared to the professionals, some discrete increases are also observed in the professional group, e.g., the SMA, the superior PMC, more anterior areas in the left cerebellar hemisphere and bilateral superior parietal areas. A more focused activation of superior left parietal and anterior ipsilateral cerebellar regions in the professional group may indicate more efficient recruitment of stored sensorimotor engrams. This view is supported by the role of the superior parietal lobe for storage of movement kinematics and by the proposed cerebellar involvement in motor automation. Moreover professional musicians revealed more anterior cerebellar activations (c.f. amateurs), suggesting a recruitment of stored movement programs of sequential finger movements during imagery
Reorganization of motor and somatosensory cortex in upper extremity amputees with phantom limb pain
No full textPhantom limb pain (PLP) in amputees is associated with reorganizational changes in the somatosensory system. To investigate the relationship between somatosensory and motor reorganization and phantom limb pain, we used focal transcranial magnetic stimulation (TMS) of the motor cortex and neuroelectric source imaging of the somatosensory cortex (SI) in patients with and without phantom limb pain. For transcranial magnetic stimulation, recordings were made bilaterally from the biceps brachii, zygomaticus, and depressor labii inferioris muscles. Neuroelectric source imaging of the EEG was obtained after somatosensory stimulation of the skin overlying face and hand. Patients with phantom limb pain had larger motor-evoked potentials from the biceps brachii, and the map of outputs was larger for muscles on the amputated side compared with the intact side. The optimal scalp positions for stimulation of the zygomaticus and depressor labii inferioris muscles were displaced significantly more medially (toward the missing hand representation) in patients with phantom limb pain only. Neuroelectric source imaging revealed a similar medial displacement of the dipole center for face stimulation in patients with phantom limb pain. There was a high correlation between the magnitude of the shift of the cortical representation of the mouth into the hand area in motor and somatosensory cortex and phantom limb pain. These results show enhanced plasticity in both the motor and somatosensory domains in amputees with phantom limb pain
Classification of EEG and fNIRS signals from Completely Locked-in State Patients for a Brain-Computer Interface communication system
Full text linkPeople suffering from complete motor paralysis with no severe deficiency in cognitive abilities, syndrome called Completely Locked in State (CLIS), remain aware of their surroundings without being able to interact and communicate in any way. In this context, the only possibility of communicating is by the techniques of Brain-Computer Interface. In this work, the focus is on the features extraction and selection on EEG and fNIRS signals and, finally, on the combination of the two to develop a system capable of classifying affirmative and negative answers from users in CLIS. The analysis considers the data collected in 4 visits to one patient. The choice to focus on a single case was made because the psychophysical considerations on the state of the patient are fundamental interpreting the results and the author of this work had the opportunity to participate directly in some acquisition. Offline analysis led to good results in the classification of fNIRS signals. Once again, using EEG signals it was not possible to successfully classify yes/no answers. Finally, the combination of EEG and fNIRS features did not improve the performance of the system.ope
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