Figure 2.

The N2pc effects in the visual and VSTM domains showed equivalent time courses (grand-averaged waveforms) and topographies in experiment 1 (a) and experiment 2 (b). ERP waveforms averaged across all participants are shown for the four-item search load over contralateral and ipsilateral locations of a representative lateral posterior electrode pair. The N2pc was elicited between 240 and 300 ms at the parietal–occipital electrodes (e.g., P7/P8) contralateral (waveforms, solid lines; topographies, blue/right side) and ipsilateral (waveforms, dashed lines; topographies, red/left side) to the side of the target. The topographic maps isolated the lateralized differences in voltage between contralateral and ipsilateral sites. These maps show the symmetrical relative differences in voltage, which is more negative over the contralateral scalp and more positive over the ipsilateral scalp. The voltage distributions are shown from posterior perspective. The color scale shows the range of possible voltage values, normalized for the topographies. Blue indicates negative voltage, and red indicates positive voltage.