Fig. 4.

Spatial representation of the population of cells recorded in area 4δc. A) The population of cells is divided into 3 main groups (forelimb, FL; hindlimb, HL; and forelimb–hindlimb, FL–HL) according to the phase of the modified cell activity with respect to the onset of the coClB/Br in the contralateral lead condition. We also show the activity of a small number of cells (N = 3) that discharged only in advance of the step over the obstacle. Cells active during the passage of the forelimb were defined as those in which the onset of activity began before the end of the burst of activity in the coClB (<0.8 steps, ≡ 0.4 step cycles) and ended <1.6 steps after the onset of activity in the coClB, approximating to the onset of activity in the coSrt. These FL cells were then divided into 2 subgroups depending on whether cell discharge began during, or just before (less than 0.2 step cycles) the step over the obstacle (SR cells), or earlier than that (SA cells). Cells active during the passage of the hindlimb were defined as those whose onset was >1.5 steps after the onset of activity in the coClB. Cells discharging between the passage of the forelimb and the hindlimb were defined as those whose discharge began <1.5 steps after the onset of activity in the coClB and in which the end of the period of discharge was >1.6. Only the principal burst of activity is plotted. (One cell was unclassified and is not plotted, hence N = 67 and not 68). Cells illustrated in Fig. 2A–G are indicated by the respective letters (a-g) and arrows. B) Localization of the 3 main groups of cells morphed onto the flattened map of the cortex taken from cat P1 (see full method in Fortier-Lebel et al. 2021). N = 64 as the 3 cells that did not fall into one of the main groups are not plotted. Cell locations were jittered by a maximum of 0.2 mm, as in Fig. 1.