Fig. 4.

DPC population temporal signals during the TPDT. (A) dPCA was applied to the temporal marginalized covariance matrix obtained from the TPDT. Population activity, sorted by classes, was projected onto the temporal dPCs. Temporal dPCs were ordered according to their explained total variance (ETV). First five temporal dPCs: first ETV, 23.9%; second ETV, 13.5%; third ETV, 9.5%; fourth ETV, 8.25%; fifth ETV, 5.84%. (B) Cumulative sum of explained signal-plus-noise variance (Left, ESNV). The dashed red line shows an estimate of the fraction of task-related variance. ESNV per component (Right). The red traces correspond to PCs; the blue traces are for dPCs. The gray trace represents the percentage of noise variance explained by the dPCs. The green points indicate which dPCs are temporal. (C) Central graph: For each neuron, we use its first and second temporal-dPC weights to plot its location on the plane. Heat-map Inset (Bottom Left) shows the joint weight distribution (20 × 20 grid, 0.01 bin side length, corresponds to black dashed square; color scale goes from 0 to 2.5%). First temporal-dPC weight distribution tends to positive values: µ = 0.028; σ = 0.035 (Top). Second temporal-dPC weights are equally distributed for positive and negative values: µ = 0.0001; σ = 0.029 (Right).