Competing at the Cybathlon championship for people with disabilities: Long-term motor imagery brain-computer interface training of a cybathlete who has tetraplegia

BACKGROUND: The brain–computer interface (BCI) race at the Cybathlon championship, for people with disabilities, challenges teams (BCI researchers, developers and pilots with spinal cord injury) to control an avatar on a virtual racetrack without movement. Here we describe the training regime and results of the Ulster University BCI Team pilot who has tetraplegia and was trained to use an electroencephalography (EEG)-based BCI intermittently over 10 years, to compete in three Cybathlon events. METHODS: A multi-class, multiple binary classifier framework was used to decode three kinesthetically imagined movements (motor imagery of left arm, right arm, and feet), and relaxed state. Three game paradigms were used for training i.e., NeuroSensi, Triad, and Cybathlon Race: BrainDriver. An evaluation of the pilot’s performance is presented for two Cybathlon competition training periods—spanning 20 sessions over 5 weeks prior to the 2019 competition, and 25 sessions over 5 weeks in the run up to the 2020 competition. RESULTS: Having participated in BCI training in 2009 and competed in Cybathlon 2016, the experienced pilot achieved high two-class accuracy on all class pairs when training began in 2019 (decoding accuracy > 90%, resulting in efficient NeuroSensi and Triad game control). The BrainDriver performance (i.e., Cybathlon race completion time) improved significantly during the training period, leading up to the competition day, ranging from 274–156 s (255 ± 24 s to 191 ± 14 s mean ± std), over 17 days (10 sessions) in 2019, and from 230–168 s (214 ± 14 s to 181 ± 4 s), over 18 days (13 sessions) in 2020. However, on both competition occasions, towards the race date, the performance deteriorated significantly. CONCLUSIONS: The training regime and framework applied were highly effective in achieving competitive race completion times. The BCI framework did not cope with significant deviation in electroencephalography (EEG) observed in the sessions occurring shortly before and during the race day. Changes in cognitive state as a result of stress, arousal level, and fatigue, associated with the competition challenge and performance pressure, were likely contributing factors to the non-stationary effects that resulted in the BCI and pilot achieving suboptimal performance on race day. Trial registration not registered SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12984-022-01073-9

EEG and psychological assessment datasets: Neurofeeedback for the treatment of PTSD

Psychological assessments were conducted through clinical interviews, to collect psychometric data for twenty-nine female survivors of the 1994 genocide against the Tutsi in Rwanda, before and after an intervention aimed at reducing Post-Traumatic Stress Disorder (PTSD) symptom severity. Three measures of trauma and four measures of wellbeing were assessed using empirically validated standardised assessments. The participants were assigned to a control group (n = 9), a motor-imagery group (MI, n = 10), and a neurofeedback group (NF, n = 10). Participants in the latter two groups received a Brain-Computer Interface (BCI) based training as a treatment intervention over a period of two weeks between the pre- and post- clinical interviews. The training involved presenting feedback visually via a game, based on real-time analysis of the EEG recorded data during the BCI-based treatment session. Participants were asked to regulate (NF) or intentionally modulate (MI) brain activity to affect/control the game.

Investigating the temporal and phase relations of oscillatory mechanisms involved in auditory binding

Abstract Introduction: Auditory binding refers to the integration of the components of a sound to form a wholistic percept. The present research explores similarities within visual and auditory binding mechanisms by testing two theories grounded in visual binding research: The General Phase Angle Hypothesis (GPAH), and the Return Phase Hypothesis (RPH). Informed by the findings, differences in the structure of the auditory binding mechanism dependent on music training were examined using a combination of experimental and neuroimaging techniques. The findings contribute to our knowledge of anticipatory coding as a dynamic system, necessary to navigate within a dynamic environment. Methods. All experiments employed an auditory priming/stimulus entrainment paradigm to evoke an auditory gamma-band response (aGBR) that is phase locked to the frequency of the primed target stimulus. Trials required a forced choice reaction time (RT) response, thus providing a psychophysical measure of the internal oscillatory mechanism involved in auditory cognition. The third study incorporated Magnetoencephalography (MEG) neuroimaging. Results. The GPAH proved a better predictor of an anticipatory effect, beyond an effect of priming – emphasised by the findings from a study guided by a capacity sharing relation derived from the Time Quantum Model (TQM). Regarding the second phase, musicians and non-musicians demonstrated differential priming effects. Conclusions. The TQM capacity sharing relation provides a template for the optimal experiment-stimulus parameters with which to investigate the phase interactions within the auditory oscillatory mechanisms required for binding. While priming enhances early bottom-up (gamma) carrier frequencies, the process also shifts critical gamma frequencies involved in auditory binding mechanisms by ~2 Hz, considered to be due to delta superimposition resulting from task demands. Furthermore, musicians demonstrate a reduced effect of priming. The implication is this population rely more on top-down processes as training strengthens the corticofugal system, allowing for more efficient feedback from higher auditory processing areas

Investigating the temporal and phase relations of oscillatory mechanisms involved in auditory binding

Abstract Introduction: Auditory binding refers to the integration of the components of a sound to form a wholistic percept. The present research explores similarities within visual and auditory binding mechanisms by testing two theories grounded in visual binding research: The General Phase Angle Hypothesis (GPAH), and the Return Phase Hypothesis (RPH). Informed by the findings, differences in the structure of the auditory binding mechanism dependent on music training were examined using a combination of experimental and neuroimaging techniques. The findings contribute to our knowledge of anticipatory coding as a dynamic system, necessary to navigate within a dynamic environment. Methods. All experiments employed an auditory priming/stimulus entrainment paradigm to evoke an auditory gamma-band response (aGBR) that is phase locked to the frequency of the primed target stimulus. Trials required a forced choice reaction time (RT) response, thus providing a psychophysical measure of the internal oscillatory mechanism involved in auditory cognition. The third study incorporated Magnetoencephalography (MEG) neuroimaging. Results. The GPAH proved a better predictor of an anticipatory effect, beyond an effect of priming – emphasised by the findings from a study guided by a capacity sharing relation derived from the Time Quantum Model (TQM). Regarding the second phase, musicians and non-musicians demonstrated differential priming effects. Conclusions. The TQM capacity sharing relation provides a template for the optimal experiment-stimulus parameters with which to investigate the phase interactions within the auditory oscillatory mechanisms required for binding. While priming enhances early bottom-up (gamma) carrier frequencies, the process also shifts critical gamma frequencies involved in auditory binding mechanisms by ~2 Hz, considered to be due to delta superimposition resulting from task demands. Furthermore, musicians demonstrate a reduced effect of priming. The implication is this population rely more on top-down processes as training strengthens the corticofugal system, allowing for more efficient feedback from higher auditory processing areas

Dynamical constants and time universals: a first step toward a metrical definition of ordered and abnormal cognition

From the point of view of the cognitive dynamicist the organization of brain circuitry into assemblies defined by their synchrony at particular (and precise) oscillation frequencies is important for the correct correlation of all independent cortical responses to the different aspects of a given complex thought or object. From the point of view of anyone operating complex mechanical systems, i.e., those comprising independent components that are required to interact precisely in time, it follows that the precise timing of such a system is essential - not only essential but measurable, and scalable. It must also be reliable over observations to bring about consistent behavior, whatever that behavior is. The catastrophic consequence of an absence of such precision, for instance that required to govern the interference engine in many automobiles, is indicative of how important timing is for the function of dynamical systems at all levels of operation. The dynamics and temporal considerations combined indicate that it is necessary to consider the operating characteristic of any dynamical, cognitive brain system in terms, superficially at least, of oscillation frequencies. These may, themselves, be forensic of an underlying time-related taxonomy. Currently there are only two sets of relevant and necessarily systematic observations in this field: one of these reports the precise dynamical structure of the perceptual systems engaged in dynamical binding across form and time; the second, derived both empirically from perceptual performance data, as well as obtained from theoretical models, demonstrates a timing taxonomy related to a fundamental operator referred to as the time quantum. In this contribution both sets of theory and observations are reviewed and compared for their predictive consistency. Conclusions about direct comparability are discussed for both theories of cognitive dynamics and time quantum models. Finally, a brief review of some experimental data measuring sensitivity to visual information presented to the visual blind field (blindsight), as well as from studies of temporal processing in autism and schizophrenia, indicates that an understanding of a precise and metrical dynamic structure may be very important for an operational understanding of perception as well as more general cognitive function in psychopathology

Electroencephalography and psychological assessment datasets to determine the efficacy of a low-cost, wearable neurotechnology intervention for reducing Post-Traumatic Stress Disorder symptom severity

The datasets described here comprise electroencephalography (EEG) data and psychometric data freely available on data.mendeley.com. The EEG data is available in .mat formatted files containing the EEG signal values structured in two-dimensional (2D) matrices, with channel data and trigger information in rows, and samples in columns (having a sampling rate of 250Hz). Twenty-nine female survivors of the 1994 genocide against the Tutsi in Rwanda, underwent a psychological assessment before and after an intervention aimed at reducing Post-Traumatic Stress Disorder (PTSD) symptom severity. Three measures of trauma and four measures of wellbeing were assessed using empirically validated standardised assessments. The pre- and post- intervention psychometric data were analysed using non-parametric statistical methods and the post-intervention data were further evaluated according to diagnostic assessment rules to determine clinically relevant improvements for each group. The participants were assigned to a control group (CG, n = 9), a motor-imagery group (MI, n = 10), and a neurofeedback group (NF, n = 10). Participants in the latter two groups received Brain-Computer Interface (BCI) based training as a treatment intervention over a sixteen-day period, between the pre- and post- clinical interviews. The training involved presenting feedback visually via a videogame, based on real-time analysis of the EEG recorded data during the BCI-based treatment session. Participants were asked to regulate (NF) or intentionally modulate (MI) brain activity to affect/control the game