Rapid attentional selection processes operate independently and in parallel for multiple targets

The question whether multiple objects are selected serially or in parallel remains contentious. Previous studies employed the N2pc component as a marker of attentional selection to show that multiple selection processes can be activated concurrently. The present study demonstrates that the concurrent selection of multiple targets reflects genuinely parallel processing that is unaffected by whether or when an additional selection process is elicited simultaneously for another target. Experiment 1 showed that N2pc components triggered during the selection of a colour-defined target were not modulated by the presence versus absence of a second target that appeared in close temporal proximity. Experiment 2 revealed that the same rapid parallel selection processes were elicited regardless of whether two targets appeared simultaneously or in two successive displays. Results show that rapid attentional selection processes within the first 200ms after stimulus onset can be triggered in parallel for multiple objects in the visual field.