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Long Multi-Stage Training for a Motor-Impaired User in a BCI Competition.

Front Hum Neurosci 2021 25;15:647908. Epub 2021 Mar 25.

Université Côte d'Azur, Inria, France.

In a Mental Imagery Brain-Computer Interface the user has to perform a specific mental task that generates electroencephalography (EEG) components, which can be translated in commands to control a BCI system. The development of a high-performance MI-BCI requires a long training, lasting several weeks or months, in order to improve the ability of the user to manage his/her mental tasks. This works aims to present the design of a MI-BCI combining mental imaginary and cognitive tasks for a severely motor impaired user, involved in the BCI race of the Cybathlon event, a competition of people with severe motor disability. Read More

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

Int J Psychophysiol 2021 Feb 26;164:71-86. Epub 2021 Feb 26.

Laboratory of Vision Science and Optometry, Faculty of Physics, Adam Mickiewicz University, Poznań, Poland; Laboratory of Vision and Neuroscience, NanoBiomedical Center, Adam Mickiewicz University, Poznań, Poland.

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). Read More

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February 2021

Immediate and after effects of transcranial direct-current stimulation in the mouse primary somatosensory cortex.

Sci Rep 2021 Feb 4;11(1):3123. Epub 2021 Feb 4.

Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Ctra. de Utrera, km. 1, 41013, Seville, Spain.

Transcranial direct-current stimulation (tDCS) is a non-invasive brain stimulation technique consisting in the application of weak electric currents on the scalp. Although previous studies have demonstrated the clinical value of tDCS for modulating sensory, motor, and cognitive functions, there are still huge gaps in the knowledge of the underlying physiological mechanisms. To define the immediate impact as well as the after effects of tDCS on sensory processing, we first performed electrophysiological recordings in primary somatosensory cortex (S1) of alert mice during and after administration of S1-tDCS, and followed up with immunohistochemical analysis of the stimulated brain regions. Read More

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February 2021

Fact retrieval or compacted counting in arithmetic-A neurophysiological investigation of two hypotheses.

J Exp Psychol Learn Mem Cogn 2021 Feb 4. Epub 2021 Feb 4.

Parenting and Special Education Research Unit.

There is broad consensus on the assumption that adults solve single-digit multiplication problems almost exclusively by fact retrieval from memory. In contrast, there has been a long-standing debate on the cognitive processes involved in solving single-digit addition problems. This debate has evolved around two theoretical accounts. Read More

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February 2021

EEG signals respond differently to idea generation, idea evolution and evaluation in a loosely controlled creativity experiment.

Sci Rep 2021 Jan 22;11(1):2119. Epub 2021 Jan 22.

Concordia Institute for Information Systems Engineering, Gina Cody School of Engineering and Computer Science, Concordia University, Montreal, QC, Canada.

Many neurocognitive studies endeavor to understand neural mechanisms of basic creative activities in strictly controlled experiments. However, little evidence is available regarding the neural mechanisms of interactions between basic activities underlying creativity in such experiments. Moreover, strictly controlled experiments might limit flexibility/freedom needed for creative exploration. Read More

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January 2021

α-tACS over the somatosensory cortex enhances tactile spatial discrimination in healthy subjects with low alpha activity.

Brain Behav 2021 Mar 6;11(3):e02019. Epub 2021 Jan 6.

Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan.

Introduction: Spontaneous oscillations in the somatosensory cortex, especially of the alpha (8 - 14 Hz) and gamma (60 - 80 Hz) frequencies, affect tactile perception; moreover, these oscillations can be selectively modulated by frequency-matched transcranial alternating current stimulation (tACS) on the basis of ongoing oscillatory brain activity. To examine whether tACS can actually improve tactile perception via alpha and gamma modulation, we measured the effects of 10-Hz and 70-Hz tACS (α- and γ-tACS) on the left somatosensory cortex on right-finger tactile spatial orientation discrimination, and the associations between performance changes and individual alpha and gamma activities.

Methods: Fifteen neurologically healthy subjects were recruited into this study. Read More

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Oscillatory EEG Signatures of Affective Processes during Interaction with Adaptive Computer Systems.

Brain Sci 2020 Dec 31;11(1). Epub 2020 Dec 31.

Fraunhofer Institute for Industrial Engineering IAO, 70569 Stuttgart, Germany.

Affect monitoring is being discussed as a novel strategy to make adaptive systems more user-oriented. Basic knowledge about oscillatory processes and functional connectivity underlying affect during naturalistic human-computer interactions (HCI) is, however, scarce. This study assessed local oscillatory power entrainment and distributed functional connectivity in a close-to-naturalistic HCI-paradigm. Read More

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December 2020

Sustained attention to response task-related beta oscillations relate to performance and provide a functional biomarker in ALS.

J Neural Eng 2021 Jan 4. Epub 2021 Jan 4.

Academic Unit of Neurology, Trinity College Dublin Academic Unit of Neurology, 152-160 Pearse St., Dublin, D02 R590, IRELAND.

Objective: To characterize the cortical oscillations associated with performance of the sustained attention to response task (SART) and their disruptions in the neurodegenerative condition amyotrophic lateral sclerosis (ALS).

Approach: A randomised SART was undertaken by 24 ALS patients and 33 healthy controls during 128-channel electroencephalography. Complex Morlet wavelet transform was used to quantify non-phase-locked oscillatory activity in event-related spectral perturbations associated with performing the SART. Read More

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January 2021

Mapping cognitive brain functions at scale.

Neuroimage 2020 Dec 15;231:117641. Epub 2020 Dec 15.

Neural Engineering and Translation Labs, Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA. Electronic address:

A fundamental set of cognitive abilities enable humans to efficiently process goal-relevant information, suppress irrelevant distractions, maintain information in working memory, and act flexibly in different behavioral contexts. Yet, studies of human cognition and their underlying neural mechanisms usually evaluate these cognitive constructs in silos, instead of comprehensively in-tandem within the same individual. Here, we developed a scalable, mobile platform, "BrainE" (short for Brain Engagement), to rapidly assay several essential aspects of cognition simultaneous with wireless electroencephalography (EEG) recordings. Read More

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December 2020

Motor Imagery Hand Movement Direction Decoding Using Brain Computer Interface to Aid Stroke Recovery and Rehabilitation.

IEEE Trans Neural Syst Rehabil Eng 2020 12 28;28(12):3051-3062. Epub 2021 Jan 28.

Motor Imagery (MI)-based Brain Computer Interface (BCI) system is a potential technology for active neurorehabilitation of stroke patients by complementing the conventional passive rehabilitation methods. Research to date mainly focused on classifying left vs. right hand/foot MI of stroke patients. Read More

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December 2020

Modulation of neural oscillations during working memory update, maintenance, and readout: An hdEEG study.

Hum Brain Mapp 2021 Mar 17;42(4):1153-1166. Epub 2020 Nov 17.

Department of Experimental Medicine, Section of Human Physiology, University of Genoa, Genoa, Italy.

Working memory (WM) performance is very often measured using the n-back task, in which the participant is presented with a sequence of stimuli, and required to indicate whether the current stimulus matches the one presented n steps earlier. In this study, we used high-density electroencephalography (hdEEG) coupled to source localization to obtain information on spatial distribution and temporal dynamics of neural oscillations associated with WM update, maintenance and readout. Specifically, we a priori selected regions from a large fronto-parietal network, including also the insula and the cerebellum, and we analyzed modulation of neural oscillations by event-related desynchronization and synchronization (ERD/ERS). Read More

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Changes in Balance, Gait and Electroencephalography Oscillations after Robot-Assisted Gait Training: An Exploratory Study in People with Chronic Stroke.

Brain Sci 2020 Nov 6;10(11). Epub 2020 Nov 6.

Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung City 404, Taiwan.

Robot-assisted gait training (RAGT) systems offer the advantages of standard rehabilitation and provide precise and quantifiable control of therapy. We examined the clinical outcome of RAGT and analyzed the correlations between gait analysis data and event-related desynchronization (ERD) and event-related synchronization (ERS) in patients with chronic stroke. We applied the Berg balance scale (BBS) and analyzed gait parameters and the ERD and ERS of self-paced voluntary leg movements performed by patients with chronic stroke before and after undergoing RAGT. Read More

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November 2020

Towards New Diagnostic Approaches in Disorders of Consciousness: A Proof of Concept Study on the Promising Use of Imagery Visuomotor Task.

Brain Sci 2020 Oct 17;10(10). Epub 2020 Oct 17.

IRCCS Centro Neurolesi Bonino Pulejo, SS113 C.da Casazza, 98124 Messina, Italy.

Background: advanced paraclinical approaches using functional neuroimaging and electroencephalography (EEG) allow identifying patients who are covertly aware despite being diagnosed as unresponsive wakefulness syndrome (UWS). Bedside detection of covert awareness employing motor imagery tasks (MI), which is a universally accepted clinical indicator of awareness in the absence of overt behavior, may miss some of these patients, as they could still have a certain level of awareness. We aimed at assessing covert awareness in patients with UWS using a visuomotor-guided motor imagery task (VMI) during EEG recording. Read More

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October 2020

Spectral Power in Marmoset Frontal Motor Cortex during Natural Locomotor Behavior.

Cereb Cortex 2021 Jan;31(2):1077-1089

Laboratory for Symbolic Cognitive Development, RIKEN Center for Biosystems Dynamics Research, Kobe, 650-0047, Japan.

During primate arboreal locomotion, substrate orientation modifies body axis orientation and biomechanical contribution of fore- and hindlimbs. To characterize the role of cortical oscillations in integrating these locomotor demands, we recorded electrocorticographic activity from left dorsal premotor, primary motor, and supplementary motor cortices of three common marmosets moving across a branch-like small-diameter pole, fixed horizontally or vertically. Animals displayed behavioral adjustments to the task, namely, the horizontal condition mainly induced quadrupedal walk with pronated/neutral forelimb postures, whereas the vertical condition induced walk and bound gaits with supinated/neutral postures. Read More

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January 2021

EEG Analysis in Coincident Timing Task Towards Motor Rehabilitation.

Annu Int Conf IEEE Eng Med Biol Soc 2020 07;2020:3027-3030

The identification of specific components in EEG signals is often key when designing EEG-based brain-computer interfaces (BCIs), and a good understanding of the factors that elicit such components can be helpful when it comes to precise, energy-efficient and time-accurate actuation of exoskeletons. CNVs (Contingent Negative Variations), ERDs or ERSs (Event-Related Desynchronizations/Synchronizations) as well as ErrPs (Error-Related Potentials) are particularly important components can be identified during motor tasks and related to specific events in a Coincident Timing (CT) task. This work investigates offline EEG signals acquired during an upper limb CT task and analyzes the task protocol with the purpose of correlating the aforementioned EEG features to movement onset. Read More

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Prior Practice Affects Movement-Related Beta Modulation and Quiet Wake Restores It to Baseline.

Front Syst Neurosci 2020 18;14:61. Epub 2020 Aug 18.

CUNY School of Medicine, The City University of New York, New York, NY, United States.

Beta oscillations (13.5-25 Hz) over the sensorimotor areas are characterized by a power decrease during movement execution (event-related desynchronization, ERD) and a sharp rebound after the movement end (event-related synchronization, ERS). In previous studies, we demonstrated that movement-related beta modulation depth (peak ERS-ERD) during reaching increases within 1-h practice. Read More

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Pre-motor deficits in left spatial neglect: An EEG study on Contingent Negative Variation (CNV) and response-related beta oscillatory activity.

Neuropsychologia 2020 10 25;147:107572. Epub 2020 Jul 25.

Dipartimento di Psicologia 39, Università degli Studi di Roma "La Sapienza", Via dei Marsi 78, 00185, Roma, Italy; Fondazione Santa Lucia, Centro Ricerche di Neuropsicologia, IRCCS, Via Ardeatina 306, 00179, Roma, Italy.

Right Brain Damaged patients with left spatial neglect (N+), are characterised by poor allocation of attention in the contralesional left side of space. In a recent study (Lasaponara et al., 2018) we showed during orienting of spatial attention with endogenous central cues, both the EEG markers reflecting the early phases of orienting (Early Directing Attention Negativity) and those reflecting the late setting-up of sensory facilitation in the visual cortex (Late Directing Attention Positivity) are disturbed in N+ when these patients attend the left side of space. Read More

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October 2020

Abnormal modulation of theta oscillations in children with attention-deficit/hyperactivity disorder.

Neuroimage Clin 2020 17;27:102314. Epub 2020 Jun 17.

State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China; Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China. Electronic address:

Previous studies have found that theta activities exhibit posterior lateralized modulation as well as midfrontal event-related synchronization (ERS) during covert visual attention in adults. The present study investigated whether these theta modulations existed in children and whether they were associated with attentional problems in attention-deficit/hyperactivity disorder (ADHD). Electroencephalography signals were recorded from typically developing (TD) children and children with ADHD (TD: n = 24; ADHD: n = 22) while they performed a cued covert visual attention task. Read More

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The global Beta test for hidden periodicities in signals and its extensions to multivariate systems.

Comput Methods Programs Biomed 2020 Oct 24;195:105550. Epub 2020 May 24.

Institute of Sound and Vibration and Research, University of Southampton, Southampton, Hampshire, UK. Electronic address:

Background And Objective: There are many phenomena that lead to changes in the power spectrum of a given signal, and their detection has been a challenge that has received considerable attention over the years. Objective Response Detection (ORD) techniques are a set of tools that perform automated tests for such a task, allowing thus to automatically track changes in the spectrum. The performance of these detectors is affected by the signal-to-noise ratio (SNR) of the recorded signal as well as the length of the available data. Read More

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October 2020

β-Oscillations Reflect Recovery of the Paretic Upper Limb in Subacute Stroke.

Neurorehabil Neural Repair 2020 05 23;34(5):450-462. Epub 2020 Apr 23.

Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.

. Recovery of upper limb function post-stroke can be partly predicted by initial motor function, but the mechanisms underpinning these improvements have yet to be determined. Here, we sought to identify neural correlates of post-stroke recovery using longitudinal magnetoencephalography (MEG) assessments in subacute stroke survivors. Read More

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Motor imagery EEG classification based on ensemble support vector learning.

Comput Methods Programs Biomed 2020 Sep 27;193:105464. Epub 2020 Mar 27.

State Key Laboratory for Manufacturing Systems Engineering, Systems Engineering Institute, Xi'an Jiaotong University, Xi'an, Shaanxi, China.

Background And Objective: Brain-computer interfaces build a communication pathway from the human brain to a computer. Motor imagery-based electroencephalogram (EEG) classification is a widely applied paradigm in brain-computer interfaces. The common spatial pattern, based on the event-related desynchronization (ERD)/event-related synchronization (ERS) phenomenon, is one of the most popular algorithms for motor imagery-based EEG classification. Read More

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September 2020

EEG to Identify Attempted Movement in Unresponsive Wakefulness Syndrome.

Clin EEG Neurosci 2020 Sep 6;51(5):339-347. Epub 2020 Apr 6.

Department of Medicine, Surgery and Health Sciences, Clinical Neurology Unit, Cattinara University Hospital, Trieste, Italy.

Assessment of consciousness following severe brain-injury is challenging. Our hypothesis is that electroencephalography (EEG) can provide information on awareness, in terms of oscillatory activity and network task-related modifications, in people with disorders of consciousness. Similar results were obtained with neuroimaging techniques; we aim at demonstrating the use of EEG, which is low cost and routinely implemented, to the same goal. Read More

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September 2020

Can a highly accurate multi-class SSMVEP BCI induce sensory-motor rhythm in sensorimotor area?

J Neural Eng 2020 Apr 1. Epub 2020 Apr 1.

Systems Design Engineering, University of Waterloo Faculty of Engineering, Waterloo, Ontario, CANADA.

Different visual stimuli might have different effects on the brain, e.g. the change of brightness, non-biological movement and biological movement. Read More

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Novel hybrid brain-computer interface system based on motor imagery and P300.

Cogn Neurodyn 2020 Apr 21;14(2):253-265. Epub 2019 Oct 21.

6Skolkovo Institute of Science and Technology (SKOLTECH), Moscow, Russia 143026.

Motor imagery (MI) is a mental representation of motor behavior and has been widely used in electroencephalogram based brain-computer interfaces (BCIs). Several studies have demonstrated the efficacy of MI-based BCI-feedback training in post-stroke rehabilitation. However, in the earliest stage of the training, calibration data typically contain insufficient discriminability, resulting in unreliable feedback, which may decrease subjects' motivation and even hinder their training. Read More

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Covariate shift estimation based adaptive ensemble learning for handling non-stationarity in motor imagery related EEG-based brain-computer interface.

Neurocomputing 2019 May;343:154-166

School of Computing and Intelligent Systems, Ulster University, Magee campus, Derry Londonderry, UK.

The non-stationary nature of electroencephalography (EEG) signals makes an EEG-based brain-computer interface (BCI) a dynamic system, thus improving its performance is a challenging task. In addition, it is well-known that due to non-stationarity based covariate shifts, the input data distributions of EEG-based BCI systems change during inter- and intra-session transitions, which poses great difficulty for developments of online adaptive data-driven systems. Ensemble learning approaches have been used previously to tackle this challenge. Read More

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Mu-Beta event-related (de)synchronization and EEG classification of left-right foot dorsiflexion kinaesthetic motor imagery for BCI.

PLoS One 2020 17;15(3):e0230184. Epub 2020 Mar 17.

School of Engineering, RMIT University, Melbourne, VIC, Australia.

The left and right foot representation area is located within the interhemispheric fissure of the sensorimotor cortex and share spatial proximity. This makes it difficult to visualize the cortical lateralization of event-related (de)synchronization (ERD/ERS) during left and right foot motor imageries. The aim of this study is to investigate the possibility of using ERD/ERS in the mu, low beta, and high beta bandwidth, during left and right foot dorsiflexion kinaesthetic motor imageries (KMI), as unilateral control commands for a brain-computer interface (BCI). Read More

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Induced Gamma-Band Activity during Actual and Imaginary Movements: EEG Analysis.

Sensors (Basel) 2020 Mar 11;20(6). Epub 2020 Mar 11.

Biomedical Engineering Group. Department of Electronics, Universidad de Alcalá. Plaza de San Diego, s/n 28801 Alcalá de Henares, Spain.

The purpose of this paper is to record and analyze induced gamma-band activity (GBA) (30-60 Hz) in cerebral motor areas during imaginary movement and to compare it quantitatively with activity recorded in the same areas during actual movement using a simplified electroencephalogram (EEG). Brain activity (basal activity, imaginary motor task and actual motor task) is obtained from 12 healthy volunteer subjects using an EEG (Cz channel). GBA is analyzed using the mean power spectral density (PSD) value. Read More

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Electrophysiological Evidences for the Rotational Uncertainty Effect in the Hand Mental Rotation: An ERP and ERS/ERD Study.

Neuroscience 2020 04 3;432:205-215. Epub 2020 Mar 3.

School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China. Electronic address:

Rotational uncertainty refers to the fact that the reaction time (RT) for identifying an upright stimulus is longer when the target stimulus is presented in a sequence of stimuli with different orientations (SU condition) than upright stimuli only (AU condition). Up until now, the rotational uncertainty effect has been only revealed by behavior measures, and its underlying neural mechanism remains unclear. In this study, using the hand mental rotation paradigm and electroencephalogram (EEG) recordings, we aimed to find the electrophysiological evidences of the rotational uncertainty from event-related potential (ERP) and event-related (de)synchronization (ERS/ERD) measurements. Read More

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Power Modulations of ECoG Alpha/Beta and Gamma Bands Correlate With Time-Derivative of Force During Hand Grasp.

Front Neurosci 2020 14;14:100. Epub 2020 Feb 14.

Clinical Neural Engineering Lab, Biomedical Engineering Department, University of Houston, Houston, TX, United States.

It is well-known that motor cortical oscillatory components are modulated in their amplitude during voluntary and imagined movements. These patterns have been used to develop brain-machine interfaces (BMI) which focused mostly on movement kinematics. In contrast, there have been only a few studies on the relation between brain oscillatory activity and the control of force, in particular, grasping force, which is of primary importance for common daily activities. Read More

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February 2020

Can Working Memory Task-Related EEG Biomarkers Measure Fluid Intelligence and Predict Academic Achievement in Healthy Children?

Authors:
Wei Luo Renlai Zhou

Front Behav Neurosci 2020 22;14. Epub 2020 Jan 22.

Department of Psychology, Nanjing University, Nanjing, China.

Background: Educational psychology research has linked fluid intelligence (Gf) with working memory (WM), but it is still dubious whether electroencephalography (EEG) markers robustly indicate Gf. This study addresses this issue and notes the relationship between WM task-related EEG markers with Gf and academic performance.

Method: A sample of 62 healthy children between the ages of 9 and 12 years was selected to perform three tasks: (1) Raven's Standard Progressive Matrices (RSPM) test to assess Gf; (2) 2-back task to assess central executive system (CES); and (3) delayed match-to-sample task to assess short-term storage. Read More

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January 2020