The P3b brain wave is not a reliable marker of conscious perception, as many experiments have failed to observe it during conscious experience. In contrast, the visual and auditory awareness negativity (VAN and AAN) have not been dissociated from consciousness, and a similar signal correlates with tactile consciousness. These awareness negativities are likely generated in sensory cortices and can be maximal contralateral to the stimulus, suggesting a generalized perceptual awareness negativity (PAN) that marks the onset of sensory consciousness.
Consciousness remains a hard problem: why does neural activity produce subjective experience, like the taste of chocolate or the feeling of a caress? Understanding this has medical and ethical implications, from assessing consciousness after brain injury to deciding whether nonhuman animals, fetuses, organoids, or advanced machines are conscious. A comprehensive theory is needed to determine which systems experience anything and to define ethical boundaries. An adversarial collaboration championing open science aims to test whether major current theories hold up.