2.6. Data Analysis
MP
To investigate the cortical effects using our BCI, we analyzed the significant event-related desynchronization (ERD) patterns in the time-frequency representation of the EEG signals. Additionally, we performed Pearson correlation analyses between cycling velocities in the Mu, low beta, and high beta rhythms.The significant ERD pattern analysis only involved successful pedal activation through MI trials with passive movement feedback. We extracted 7-s segments aligned to the MP’s onset movement (being 0 s the onset). Each segment included a 2-s baseline period preceding MI recognition (−3 to −1 s), a 1-s MI period (−1 to 0 s) for pedal activation, and a 4-s period after MI recognition representing passive movements (0 to 4 s). EEG data from −2.0 to −1.0 s served as a reference or baseline, whereas data from 0 to 3 s represented cortical activity during passive pedaling (PP). The segments were first band-pass filtered from 0.1 to 40 Hz and later analyzed through the t-percentile bootstrap algorithm to determine significant ERD patterns, considering significance levels of 0.01 and 0.20 (confidence intervals of 99% and 80%, respectively).