Temporal evolution of PVs across rest and delay epochs for both monkeys. (a) The specific task cases were shown on the left of each row, in which the arrow pointed from the start position (blue dot) to target (solid yellow dot). The dashed yellow circle represented other target candidates. The grey, blue, and red arrows represented PVs during rest, delay 1, and delay 2 epochs, respectively. The middle and right columns represented the PVs evolution for monkeys B and C, respectively. PV evolution in one row for a specific monkey represented the summation of PVs in 20 trials with the same task case for stability. (b) The same as (a) but with start point at the left. Trials were from sessions B140530 and C150430 for monkeys B and C, respectively.