The effects of cognitive and perceptual load on inattentional blindness

Inattentional blindness is often attributed to limited attentional resources. In principle, tasks that are more effortful, those that place greater demands on attention, should result in less noticing of unexpected objects. But that load on attention can take different forms, including both perceptual and cognitive components. Increasing the perceptual load by making selective attention more difficult typically increases inattentional blindness for unexpected objects, but the evidence for an effect of increased cognitive load on noticing has been more limited and mixed. In a set of five inattentional blindness studies (approximately N = 100/condition), we varied both perceptual and cognitive load. Higher perceptual load resulted in far less noticing of unexpected objects but only in the absence of an additional cognitive load task. Adding a cognitive load task lowered the overall noticing rate and reduced or eliminated the effect of perceptual load on noticing. But the amount of cognitive load (remembering 1 vs. 3 letters) made little difference. This interaction between the effects of cognitive and perceptual load might help to explain inconsistencies in evidence for an effect of cognitive load on inattentional blindness as well as the lack of a relationship between individual differences in cognitive ability measures and noticing of unexpected objects. All data and materials for this research are available at https://osf.io/gw49q. (PsycInfo Database Record (c) 2026 APA, all rights reserved).