Perceptual Load and Color Singletons 1 Running head: PERCEPTUAL LOAD AND COLOR SINGLETONS Does Low Perceptual Load Enable Capture by Color Singletons?

There is considerable debate as to whether color singletons can capture attention in a stimulus-driven manner. In this study, we explore one potential capture enabling condition – low perceptual load. To test this hypothesis, we manipulated perceptual load in a flanker task in which flanking letters sometimes were color singletons. If low load enhances capture by color singletons, then color singletons should produce an especially large increase in overall reaction times and in flanker-target compatibility effects. Neither of these predictions was confirmed in any of the four experiments reported here, although we did replicate the classic load effects from previous studies. These experiments indicate that although perceptual load does strongly modulate overall performance, it does not facilitate capture by color singletons. This finding contrasts sharply with findings from other types of salient stimuli (abrupt onsets and moving objects). Implications for theories of attentional capture will be discussed.