A tale of two theories: A meta-analysis of the attention set and load theories of inattentional blindness.

Public Significance Statement Most of us experience inattentional blindness every day, sometimes as trivial errors like failing to notice a grammatical error in a passage of text. Other times, the phenomenon poses more serious concerns, such as missing a pedestrian while driving. The importance of studying inattentional blindness is therefore clear-not only can it tell us something about how the mind and brain work, but it can help inform interventions for the lapses in attention that occur in everyday life. Our analysis examines the two leading theories of inattentional blindness and finds that the most critical component in explaining why the phenomenon occurs is seemingly the relevance of the information to the observer. Our work emphasizes that more research is needed to unpack how these theories interact, as well as how inattentional blindness may be shaped by situational factors such as time and task. Inattentional blindness (IB), the failure to notice something right in front of you, offers cognitive scientists and practitioners alike a unique means of studying the nature of visual perception. The present meta-analysis sought to provide the first synthesis of the two leading theories of IB-attention set and load theory. We aimed to estimate the magnitude of the effect of each, how they interact, and how task parameters moderate the magnitude of IB summary estimates. We further sought to address several theoretical issues that have persisted within this broad literature. A total of 317 effect sizes from 81 studies that had manipulated attention set or load were synthesized in a multilevel meta-analysis. Results indicated no significant difference between the attention set summary estimate (odds ratio [OR] = 3.26, 95% confidence interval [95% CI] [2.33, 4.57]) and the load summary estimate (OR = 1.75, 95% CI [1.10, 2.79]). Theoretical moderators included a difference between feature attention sets (OR = 5.02, 95% CI [2.95, 8.55]), semantic attention sets (OR = 2.64, 95% CI [1.64, 4.25]), and inherent sets (OR = 1.90, 95% CI [1.35, 2.68]), while perceptual load (OR = 2.55, 95% CI [1.66, 3.92]) and cognitive load (OR = 1.67, 95% CI [1.14, 2.44]) were more comparable. The primary task was found as a key task parameter that moderated summary estimates. The attention set summary estimate was moderated by the number of targets and distractors, whereas the load summary estimate was moderated by the full attention (FA) trial exclusion criterion. Analyses indicated any potential publication bias were overall not likely to impact our conclusions. We discuss the implications of results for a conceptual understanding of IB and how the phenomenon can be more reliably studied in future.