a positive trendp = 0.054
A positive trend between left M1 activity and right spinal cord GM activity was present but did not reach statistical significance (β = 0.034 ± 0.018, t = 1.954, p = 0.054), and a negative association between left M1 activity and left spinal cord GM activity was observed (β = -0.039 ± 0.015, t = -2.553, p = 0.013) ( Supplementary Fig.