Extended Data Figure 7: Activity analysis focusing on the first 500 ms of each movement.

For the activity analyses in the main figures that used the duration of 3 s after movement onset, we repeated the same analyses focusing on the first 500 ms of each movement (median time from movement onset to reward = 506 ms). This early activity shows progression throughout learning, similar to when activity over 3 s was considered. a, Standard deviation of the timing of activity onsets for movement-related excitatory neurons over sessions, indicating a gradual refinement of activity timing (r = −0.18, P < 0.001). Neurons that were active in less than five trials of a given session were excluded from this analysis. The first bin contains only one data point and thus does not have an error bar. This analysis is equivalent to Fig. 2g. b, Pairwise trial-to-trial correlation of temporal population activity vectors increases with learning (r = 0.38, P < 0.001). Temporal population activity vector was defined as a concatenation of the activity traces of all movement-related neurons and thus maintained temporal information within each movement. This analysis is equivalent to Fig. 2h. c, Correlation of spatiotemporal activity with the learned activity pattern is a function of the correlation of movement with the learned movement pattern in expert sessions. Movements similar to the learned movement pattern but made in naive sessions display activity very different from the learned activity pattern (P = 0.28 and <0.001 in the bins 1 and 2–10, respectively, Wilcoxon rank sum test). This analysis is equivalent to Fig. 3b. d, Pairwise trial-to-trial correlation of temporal population activity vectors plotted as a function of movement correlation on those trials. A strong relationship between population activity and movement emerges during learning (P = 0.08, = 0.08, = 0.004, <0.001, = 0.002, <0.001, = 0.001, = 0.002, <0.001 and = 0.046 for each bin, Wilcoxon rank sum test). This analysis is equivalent to Fig. 3c. All error bars are s.e.m.