Fig. 6. Coupling strength of rule 3 between ipsilateral legs. Likelihood of protraction in posterior legs (receiver legs) relative to t_trans01, i.e. time to of lift-off, in anterior legs (sender legs, see Fig. 5). Coupling strength is evaluated for the straight walking sequence of the pre-stimulus period (solid lines, baseline marked by solid arrowhead) and the curve walking sequence of the late stimulus period (dotted lines, baseline marked by open arrowhead). Error bars indicate 95% confidence intervals. Inserts indicate the leg pair concerned (see Fig. 5B). Coupling strength associated with rule 3 is indicated by the peak likelihood of a receiver leg to be in swing mode prior to lift-off of the sender leg. Coupling strength changes with the behavioural context of the animal. During curve walking it increases in outer legs and decreases or remains similar in inner legs.