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. 2022 Mar 8;33(2):290–315. doi: 10.1093/cercor/bhac068

Fig. 2.

Fig. 2

Examples of task-related cells in area 4δc. A–C) Three examples of limb-dependent cells, modified only (A, C) or primarily (B) during the contralateral lead condition (red traces). E, F) Two limb-dependent cells that each discharged similarly during the contralateral and ipsilateral lead conditions. For each of these cells, in A–C and E, F, we illustrate peri-event histograms (PEHs), and raster displays of cell activity synchronized to the onset of activity in the contralateral cleidobrachialis or brachialis (coClB/Br) in both the contralateral and ipsilateral lead conditions: see EMGs in D and Gi. G) An example of a limb-independent cell. In Gi, the activity is triggered on the coClB in both conditions, as for A–F, while in Gii, the data are triggered on the onset of activity in the ClB of the lead limb. All raster displays are rank-ordered according to the duration of the flexor burst. Red traces indicate the contralateral lead condition; green traces represent the ipsilateral lead condition; blue traces indicate activity during unobstructed (control) locomotion (see key in part Gii). Shaded areas around the blue traces on the PEHs indicate the interval of confidence (P = 0.01) of the standard error of the mean of the control activity. Red horizontal line below the PEH indicates the period of significant task-related modifications in discharge activity during contralateral lead; green line indicates significant activity during the ipsilateral lead. D) Averaged EMG activity recorded simultaneously with the cell illustrated in B. Vertical black lines in A–G delimit step cycles (−2 to +2). Numbers in parentheses below the x-axis and adjacent to the coClB and iClB muscle bursts indicate steps with respect to the step over the obstacle. coLead, step over the obstacle when the contralateral limb leads; iLead, activity when the ipsilateral limb leads; N, number of step cycles included for each condition and the control; Srt, anterior head of sartorius; St, semitendinosus. The color key in part Gii pertains to the entire figure.