Fig. 1

a Participants walked on a treadmill while watching a speed-matched immersive virtual hallway with and without continuous mediolateral (ML) optical flow perturbations with an amplitude of 0.35 m, applied as detailed in the current methods section. b Participants participated in two sessions performed on separate days separated by at least 1 week and in fully randomized order. Both sessions consisted of a 2 min “baseline” walking period without perturbations. In one session (“Experimental”), participants then walked for 10 min in the presence of perturbations, followed immediately by a 1-min “post” period without perturbations. In the other session (“Control”), participants simply walked for 10 min without perturbations. For analysis, we refer to the first and last minute of each 10-min prolonged walk as “early” and “late”, respectively