Supplementary Figure 12: The activity of the trigger and targets became more correlated after closed-loop conditioning.

(a) The inferred spike rate of the target cells and background cells in closed-loop and open-loop conditions aligned to the onsets of the detected events in the trigger cells: after closed-loop conditioning, the inferred spike rate of the target cells but not the background cells became significantly higher during periods when the trigger cell is active (dark gray bar, 170-ms window following an event in the trigger) than that during periods when the trigger cell is less active (n = 57, P = 0.004 for target cells and n = 451, P = 0.61 for background cells, Wilcoxon signed rank test (two-sided)); neither the target cells nor the background cells after open-loop conditioning showed an increase in spike rate that is locked to the events of the trigger cell (n = 56, P = 0.61 for target cells; n = 424, P = 0.17 for background cells. Center values are mean; shaded areas are s.e.). (b) Population coupling within the trigger-targets increased significantly after closed-loop photostimulation (* P = 0.040, Wilcoxon signed-rank test (one-sided), n = 63 pairs of coupling within 57 target cells and 6 trigger cells in 6 animals; center values are mean; error bars are s.d.). The increase in the coupling of one cell to the other cells in the trigger-targets group is negatively correlated with the distance between the target cell to the trigger cell (Pearson’s correlation coefficient r = –0.39, P = 0.0028) and the average distance between the target cell and the other target cells (r = –0.38, P = 0.0033). (c) Pearson’s correlation coefficients between the calcium transients of the trigger cells and their associated targets before and after conditioning (*P = 0.029, Wilcoxon signed-rank test (one-sided); n = 57 pairs of 57 target cells and 6 trigger cells in 6 animals). (d) Pearson’s correlation coefficients between the calcium transients of the target cells that were photostimulated at the same time did not increase (n.s. P = 0.46, Wilcoxon signed-rank test (one-sided); n = 244 pairs of 57 target cells in 6 animals; center values are mean; error bars are s.d.).