Figure 4.

The ensemble firing patterns in the step cycle in each condition in the rat and trial also displayed in Figure 2 and 5. A, the normalized firing rates of neurons shown as a thermogram and as the average of the ensemble firing rate in the step cycle respectively. These showed different patterns under baseline (BL), simple elastic load (E) and BMI with elastic load conditions (BMI/E). The average firing rate was normalized to the firing rate peak across baseline, elastic load, and BMI with elastic load conditions. B. First half trial in each condition shown as a thermogram. C. Second half trial in each condition shown as a thermogram. D–E. The whole trial average rates normalized to the whole trial peak in each condition. Vertical dotted lines: peak timings, dotted horizontal bars: average swing phase, solid horizontal bars: Full width at 0.5. D. Whole trial. E. First half trial. F. Second half trial. In each half trial, cells demonstrated different firing patterns in different adaptation fields as well as different training phases during locomotion. In the baseline condition cells fired at specific preferred step phases in the 1^st half and then increased phase dispersion to spread much broader in the 2^nd half trial. In the simple elastic load condition, these cells have wider firing phase dispersion initially and then also spread in the 2^nd half trial, although there were still clear firing phases. In the BMI with elastic load condition, there were strong firing phase preferences in both the 1^st half trial and the 2^nd half trial.