Right or left trials were selected for the statistical analysis, based on the affected limpb of the patient.
The task began with a practice block of 20 trials, including 5 congruent left trials (all fish facing to the left), 5 congruent right trials (all fish facing to the right), 5 incongruent left trials (middle fish facing left and flanking fish facing right), and 5 incongruent right trials (middle fish facing right and flanking fish facing left).
Right or left trials were selected for statistical analysis based on the affected leg.
In total there were 40 trials comprising 20 trials for the left and 20 trials for the right hand MI with the left and right cues presented to the participants in a random order.
After each block of 20 trials, the side bias was adjusted for the following 10 trials: for example if the test stimulus had appeared in 14 trials on the left and in six trials on the right, in the following eight (i.e. 14 6) trials the stimulus would appear on the right key to equalize the overall number of trials presented on the right and left.
To generate the accumulator model's reverse correlation, each trial was assigned as the left and right trial, according to the model's prediction for that trial.
Within each movement condition 50 trials were performed in a blocked presentation in the left and 50 trials in the right hemi-workspace.
To measure magnetic spectral power elicited by finger movements, accumulated spectrograms from 100 trials for the left finger and 100 trials for the right finger were computed separately.
Model classification performance was estimated using the area under the receiver-operator characteristic curve (AUC), calculated after leave-one-out cross-validation, where the model was fit to every trial but one, and the model was then used to predict the outcome of the left-out trial.
For the quantification of learning and the measurement of the magnitude and direction of the force anticipated by the left hand, catch trials were included in which the hands were unlinked.
