Surprisingly, we also found higher sensitivity to sensory input following absence cues than presence cues and speculate about how an asymmetry between gathering evidence in favour of stimulus presence and absence may account for this result.

Presence cues and valid content cues independently affected participants’ confidence in having seen a grating. We replicated these effects and reproduced them in simulations using a post-hoc adapted version of the higher-order state space (HOSS) model.

This moderating role of presence cues on content cues was also observed when participants falsely perceived a grating with high confidence even when none was actually displayed.

As expected, participants’ orientation responses were biased towards the content cue. Interestingly though, this bias was scaled by the accompanying presence cue so that stronger content cue effects were found if paired with a presence than with an absence cue.

We asked participants to judge both the presence and content (orientation) of noisy grating stimuli while preceding compound cues predicted the likelihood of both overall grating appearance as well as its orientation.