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Preregistration of protocol, hypotheses and data analysis plan. Two-phase Brain Computer Interface approach. Testing whether two days of priming using TMS-neurofeedback improves control of an EEG BCI.

Data associated with the article 'Modulating functional connectivity with the right inferior frontal cortex by self-upregulation of the brain’s Beta rhythm'

Considerable evidence attests to a relationship between executive function and falls. Notable among cognitive elements related to fall risk is the ability to suppress a highly automatic but unwanted action – i.e., response inhibition. Although the ability to stop may seem an unlikely foundation for maintaining balance, there are many complex situations in daily life where we must adapt instinctual actions that could lead to further instability. Most of what we know about the role of response inhibition in balance control is based on correlations between cognitive test performance and self-reported falls, leaving a sizable gap in understanding the mechanisms linking inhibition and balance control. In the current study we expand from traditional balance assessments that accentuate reflexive action and instead impose a need to suppress a prepotent balance recovery step. We leverage recent techniques developed in cognitive neuroscience that can expose a chronology of neuromuscular events leading to successful inhibition. Specifically, we will measure neural markers shown to predict successful inhibition in seated voluntary reaction time tasks using focal hand responses, and apply this to a balance recovery stepping task. Given the link between executive function and falls, there is a strong reason to believe that research designs which incorporate a need for inhibition in balance recovery will offer new critical insights into this poorly understood risk factor leading to falls in vulnerable populations.

Code and data for Psychophysiology paper

The aim of this study is to identify the predictors of successful nicotine abstinence in a longitudinal design, using a machine learning approach. Our analysis will include a range of data – psychological, behavioral, genetic and electrophysiological – each of which likely has a small effect size, but in combination may predict successful smoking abstinence. We will use a regularization method, which penalizes model complexity, to attenuate overfitting. We will also use both internal and external validation to evaluate the model the performance and test the generalizability of our models.

It is hypothesized that deep sleep is essential for restoring the brain's capacity to learn efficiently, especially in regions heavily activated during the day. However, causal evidence in humans has been lacking due to the inability to sleep deprive one target area while keeping the natural sleep pattern intact. Here we introduce a novel approach to focally perturb deep sleep in motor cortex, and investigate the consequences on behavioural and neurophysiological markers of neuroplasticity arising from dedicated motor practice. We show that the capacity to undergo neuroplastic changes is reduced by wakefulness but restored during unperturbed sleep. This restorative process is markedly attenuated when slow waves are selectively perturbed in motor cortex, demonstrating that deep sleep is a requirement for maintaining sustainable learning efficiency., Deep sleep is hypothesized to restore the brain's capacity to learn. Here the authors provide causal evidence by specifically perturbing slow wave activity over the motor cortex during NREM sleep in humans and demonstrate a reduction in neurophysiological markers of plasticity and capacity for motor learning.

BackgroundIn the last decade, interest in combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) approaches has grown substantially. Aside from the obvious artifacts induced by the magnetic pulses themselves, separate and more sinister signal disturbances arise as a result of contact between the TMS coil and EEG electrodes.New methodHere we profile the characteristics of these artifacts and introduce a simple device – the coil spacer - to provide a platform allowing physical separation between the coil and electrodes during stimulation.ResultsEEG data revealed high amplitude signal disturbances when the TMS coil was in direct contact with the EEG electrodes, well within the physiological range of viable EEG signals. The largest artifacts were located in the Delta and Theta frequency range, and standard data cleanup using independent components analysis (ICA) was ineffective due to the artifact’s similarity to real brain oscillations.Comparison with Existing MethodWhile the current best practice is to use a large coil holding apparatus to fixate the coil ‘hovering’ over the head with an air gap, the spacer provides a simpler solution that ensures this distance is kept constant throughout testing.ConclusionsThe results strongly suggest that data collected from combined TMS-EEG studies with the coil in direct contact with the EEG cap are polluted with low frequency artifacts that are indiscernible from physiological brain signals. The coil spacer provides a cheap and simple solution to this problem and is recommended for use in future simultaneous TMS-EEG recordings.

Background Therapy that combines repetitive training with non-invasive brain stimulation is a potential avenue to enhance upper limb recovery after stroke. This study aimed to investigate the feasibility of transcranial Random Noise Stimulation (tRNS), timed to coincide with the generation of voluntary motor commands, during reaching training. Methods A triple-blind pilot RCT was completed. Four stroke survivors with chronic (6-months to 5-years) and severe arm paresis, not taking any medications that had the potential to alter cortical excitability, and no contraindications to tRNS or MRI were recruited. Participants were randomly allocated to 12 sessions of reaching training over 4-weeks with active or sham tRNS delivered over the lesioned hemisphere motor representation. tRNS was triggered to coincide with a voluntary movement attempt, ceasing after 5-s. At this point, peripheral nerve stimulation enabled full range reaching. To determine feasibility, we considered adverse events, training outcomes, clinical outcomes, corticospinal tract (CST) structural integrity, and reflections on training through in-depth interviews from each individual case. Results Two participants received active and two sham tRNS. There were no adverse events. All training sessions were completed, repetitive practice performed and clinically relevant improvements across motor outcomes demonstrated. The amount of improvement varied across individuals and appeared to be independent of group allocation and CST integrity. Conclusion Reaching training that includes tRNS timed to coincide with generation of voluntary motor commands is feasible. Clinical improvements were possible even in the most severely affected individuals as evidenced by CST integrity., Journal of NeuroEngineering and Rehabilitation, 14, ISSN:1743-0003

Cross-education (CE) is the process whereby training with one limb leads to subsequent improvement in performance by the opposite untrained limb. We used multimodal neuroimaging in humans to investigate the mediating neural mechanisms by relating quantitative estimates of functional and structural cortical connectivity to individual levels of interlimb transfer. Resting-state (rs)-fMRI and diffusion weighted imaging (DWI) scans were undertaken before unilateral ballistic wrist flexion training. The rs-fMRI sequence was repeated immediately afterward. The increase in performance of the untrained limb was 83.6% of that observed for the trained limb and significantly greater than that of a control group who undertook no training. Functional connectivity in the resting motor network between right and left supplementary motor areas (SMA) was elevated after training. These changes were not, however, correlated with individual levels of transfer. Analysis of the DWI data using constrained spherical deconvolution-based tractography indicated that fractional anisotropy and apparent fiber density in tracts connecting bilateral SMA were negatively correlated with and predictive of transfer. The findings suggest that interhemispheric interactions between bilateral SMA play an instrumental role in CE and that the structural integrity of the connecting white matter pathways influences the level of transfer., The Journal of Neuroscience, 37 (10), ISSN:0270-6474, ISSN:1529-2401