Fig 6. Baseline observation condition.

(A) H-reflexes recorded in the right FCR muscle of right-handed observers are not modulated during observation of one cycle of a sinusoidal movement of a metal platform (B, average movement trace performed by the platform in all different experiments (±SEM). In panel (A) the cumulative plot of the average data points from all subjects could not be fitted by a sinewave. Down and Up = directions of the moving platform. No resonant response is recorded when subjects are observing the metal platform oscillating without the hand (with the same sinusoidal rhythm as in Figs 2, 4 and 5, and H-reflex amplitude variations are the result of random variability rather than a modulation induced by the observation task.