Plot of the preferred orientation during sample stimulus presentation (x-axis) and delay (y-axis) periods. Each dot represents one neuron. Note that all neuronal data during sample stimulus presentation and delay periods are sorted by sample stimulus tilt angle. A, Plot of the preferred orientation during the former half of the delay against that during the sample presentation period for 31 neurons that showed selective activity during both the sample presentation and the former delay. B, Plot of the preferred orientation during the latter half of delay against that during the sample presentation period for 19 neurons that showed selective activity during both the sample presentation and the latter delay.