Fig. 3. Phase relations between step and sound rhythms. (A) Interval histogram of step cycle durations ranging between 250 and 600 ms, with a mean of 396 ms. (B) Phase diagram of chirps within the step cycle. This revealed no indication that the step cycle was coupled to the chirp pattern. (C) Double pulse paradigm with the first and last two syllables of a chirp presented from contralateral (right), but the middle two syllables presented from ipsilateral (left) speakers (top traces). Stepping cycles were sorted into 20 bins according to the phase values of acoustic stimulation; only four bins are shown for clarity. Only when the ipsilateral two syllables occurred during swing phase, were left–right front leg movements smaller in the following stance phase (asterisk).