You open the refrigerator looking for the ketchup but you don’t see it. You ask your spouse “Where did you put the ketchup?” They look and say “It’s right there in front of you!” And then, surprised, suddenly you see it. You have just experienced inattentional blindness (IB).
Inattentional Blindness happens to most of us everyday. It may manifest as “refrigerator blindness” or “pantry blindness” or, more seriously, “pedestrian blindness” while driving. But what causes IB? There are two main theories: Attention Set and Load Theory (Attention Capacity). Attention Set predicts IB will occur when a person is looking for one thing and doesn’t see something else, which doesn’t seem to fit the “refrigerator blindness” example but could explain “pedestrian blindness”. Load Theory, on the other hand, predicts IB will occur when attention capacity is somehow overloaded, which could explain both refrigerator and pedestrian blindness. Hutchinson and colleagues set out to discover whether data from 81 different studies testing one or both of the theories could help determine which theory did a better job overall of explaining IB. Their conclusion: both theories do a pretty good job of explaining Inattentional Blindness but do so under different circumstances.
Abstract
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.
Citation
Hutchinson, B. T., Pammer, K., Bandara, K., & Jack, B. N. (2022). A tale of two theories: A meta-analysis of the attention set and load theories of inattentional blindness. Psychological Bulletin, 148(5-6), 370–396.
Dr Martin Fracker 