Attention robustly dissociates objective performance and subjective visibility reports

Background: Findings of subjective inflation, in which subjective reports of unattended, peripheral stimuli are stronger than the accuracy of sensory processing would suggest, have motivated higher-order theories of consciousness. However, empirical tests of subjective inflation have been surprisingly limited. Generally they have used a single pair of near-threshold stimulus strengths–weaker for attended and stronger for unattended–to equate objective performance, leaving it unclear whether inflation arises from decision biases and whether inflation extends beyond threshold perception. Goal: In a preregistered adversarial collaboration, we rigorously tested whether attention dissociates subjective reports and objective performance across a range of stimulus strengths and types. Methods: In three experiments, human observers (n=30/experiment) performed a spatial attentional cueing task. On each trial, observers viewed up to four peripheral targets, which varied independently across 7 stimulus strengths. A central precue (60% valid, 20% neutral, 20% invalid) directed attention to one or all target locations. A response cue instructed observers to simultaneously make 1) an objective orientation report and 2) a subjective visibility report. Targets were texture-defined figure-ground ovals (Experiments 1 and 2) or contrast-defined gratings (Experiment 3), presented at threshold (Experiments 1 and 3) or suprathreshold (Experiment 2) stimulus strengths. To assess subjective inflation, we developed an area-under-the-curve approach to quantitatively relate objective and subjective reports across stimulus strengths for matched levels of orientation discriminability. Results: We found strong and consistent subjective inflation under inattention across all experiments. Across a range of threshold and suprathreshold stimulus strengths, and different stimulus types, subjective visibility was reported as higher for unattended vs. attended stimuli when orientation discriminability was equated. Conclusion: Inattention robustly inflates subjective visibility reports, and inflation is not confined to threshold vision. Whether sensory signals are sufficient for explaining subjective visibility reports when they come apart from objective performance may help arbitrate between competing theories of consciousness.