Evidence against the low-salience criticism of signal suppression

There has been a longstanding debate about whether salient stimuli, such as uniquely colored objects, have the automatic power to capture attention. The signal suppression hypothesis proposed a resolution whereby salient stimuli have inherent power to capture attention, but that capture can be prevented by inhibiting such stimuli. This hypothesis has recently been criticized on the grounds that initial studies supporting it may have used singletons that were only weakly salient (the low-salience criticism). According to this argument, salient stimuli have the automatic power to capture attention; but only when made sufficiently salient. This criticism may not be well-founded, however, as studies on the topic have not used an objective measure of salience (or, indeed, any measure at all) to evaluate their stimuli. We have recently developed a new psychophysical technique to measure salience. The current study used this technique to compare salience of color singletons from an original study of signal suppression (Gaspelin et al., 2015) and a study purporting to increase salience (Wang & Theeuwes, 2020). We found that, if anything, color singletons were more salient in the original studies supporting signal suppression than in the studies purporting to improve salience. Ultimately, these findings suggest that the low-salience criticism of the signal suppression hypothesis is unfounded.