The act of detecting a stimulus contaminates measures of conscious experience with unrelated cognitive factors

A central challenge in consciousness research is determining whether observers truly experience a stimulus. However, present/absent detection judgments are often biased by contextual factors, making it difficult to isolate conscious perception from non-perceptual influences. Traditional psychophysical methods cannot disentangle these components. To address this, we conducted in-person experiments (N=505) in which participants detected and reproduced dim stimuli under three contextual manipulations: attentional cues, asymmetrical base rates, and payoff schemes. Using a Hurdle-Gaussian model, we separated perceptual from non-perceptual effects. We found that statistical priors (base rate) and reward structures (payoff) induced non-perceptual shifts in reproduction behavior, whereas attentional cues led to shifts that reflect changes in conscious experience. Critically, when reproduction tasks were embedded within a detection context, reports of conscious experience were contaminated by non-perceptual effects. This highlights the need for caution in using and interpreting results relying on detection judgments in consciousness research.