ERPs elicited by the probe at the +2 and the +8 positions.

<p>Group mean difference waves of probe-locked ERPs elicited by target-probe sequences minus target only sequences as a function of probe probability. Similarly, difference waves of probe-locked ERPs elicited by probe only sequences minus the sequences with neither the target nor the probe as a function of probe probability. A: traces from the parietal electrode POz. B: mean amplitude and latency from parietal electrodes (i.e., P3, Pz, P4, PO3, POz, and PO4). C: the bottom panel shows the topographic P3b amplitude distribution from the corresponding experimental conditions during peak latency. TP_80%P: both target and probe were present and 80% probe at the designated temporal position; P_80%P: only probe was present and 80% probe at the designated temporal position; TP_20%P: both target and probe were present and 20% probe at the designated temporal position; P_20%P: only probe was present and 20% probe at the designated temporal position.