FIGURE 1.

Overview of the intervention sessions. Prior to the interventions 10 TMS stimuli were applied at each of six different intensities. The interventions (spaced at least 48 h apart) consisted of two phases. In phase one participants completed 30 dorsiflexion movements while EEG data were collected. In phase two, participants were exposed to concurrent motor imagination and peripheral nerve stimulation. In the associative BCI_offline intervention, the stimulation was provided during each motor imagery trial and the timing set in relation to the peak negativity obtained from the EEG data of phase one. In the associative BCI_online intervention, the stimulation was only provided if an MRCP was detected. The detection algorithm was trained from the data obtained in phase one. For each modus participants completed 30 imagery trials. Immediately following and 30 min after the cessation of the interventions, another 10 TMS stimuli were applied at each of six different intensities.