Ariel Berlinger¹, Ariel Goldstein², Baruch eitam³; ¹University of haifa, ²The Hebrew University, ³University of Haifa, University of British Columbia

Much of the debate over sparse vs. rich accounts of consciousness hinges on whether report failures reflect limitations of conscious experience itself or of post-perceptual access mechanisms. Failures to report may reflect limits of experience, limits of access, or both. We adapt an experimental paradigm that pushes the sparse position by demonstrating systematic report failures for clearly visible, meaningful stimuli, under no capacity constraints (minimal set-size and memory load) while accounting for mind wandering and surprise. In two online experiments (n=60 and n=47), participants viewed flower-in-a-pot stimuli for 1,000ms. They reported one object's color (flower or pot) until a surprise probe tested knowledge of the irrelevant object’s color. In the second experiment, the stimuli rotated and appeared at different locations, minimizing the effects of focal spatial attention and mind wandering. As expected, the relevant color was reported near-perfectly (Exp1: 99%; Exp2: 96%), indicating engagement and comprehension. Following repeated reporting of the task-relevant object’s color, around mid-experiment, an unexpected probe was presented to quantify the effect of surprise. Surprise reduced the subsequent success in reporting the relevant object’s color (Exp1: 67%, CI [55,79]; Exp2: 55% CI[41,70]). Critically, when unexpectedly probed for the irrelevant object’s color, performance was substantially lower, reaching chance level (Exp1: 20% CI[10,30]; Exp2: 23% CI[11,36]; chance=25% 4-alternative-forced-choice). Reporting of the relevant color’s object following the probe of the irrelevant object’s colour, showed only the effect of surprise (Exp1: 67% CI[55,79]; Exp2: 74% CI[62, 87]). In consequent trials, after both colors were deemed relevant, performance rebounded (Exp1: 85% CI[76, 94]; Exp2: 73% CI[64,82]). We term this pattern Irrelevance-Induced Agnosia; task irrelevance alone can drive striking report failures for salient stimulus features beyond the effect of surprise, spatial attention, attentional disengagement, and arguably, conscious perception itself. These results constrain the use of report as a proxy for conscious perception.

Acknowledgements: This research was supported by The Israel Science Foundation (ISF) grant number 1714/23 and The Bi-national Science Foundation (BSF) grant number 2022/321.