Evidence for a fixed capacity limit in attending multiple locations

摘要: A classic question concerns whether humans can attend multiple locations or objects at once. Although it is generally agreed that the answer to this “yes,” limits on ability are subject extensive debate. According one view, attentional resources be flexibly allocated a variable number of locations, with an inverse relationship between selected and quality information processing each location. Alternatively, these might quantized in “discrete” fashion enables concurrent access small locations. Here, we report series experiments comparing alternatives. In experiment, cued participants spatial asked them orientation single, briefly presented target. all experiments, participants’ errors were well-described by model assumes fixed upper limit attended. Conversely, poorly described flexible-resource no Critically, showed discrete predicted cue-evoked neural activity elicited before onset target array, suggesting performance was limited selection processes began prior subsequent encoding memory storage. Together, findings constitute novel evidence supporting hypothesis human observers only instant.