What We Don't Know Yet

Do they happen during cardiac arrest, during early recovery, or during a brief lucid window near death? This matters enormously for mechanistic explanations. Some EEG evidence suggests burst activity near death; other evidence suggests perceptions are reconstructed during recovery. The question is not settled.

AWARE documented one corroborated case across hundreds of arrests. How many verified hidden-target identifications, under what methodological conditions, would the scientific community require before accepting anomalous perception as real? This is a question about the sociology of science as much as the evidence itself.

Filter theory, nonlocal consciousness, and transmission models all assert that the brain constrains rather than generates consciousness. But none has produced a specific, testable mechanism that makes novel predictions. What would distinguish these models from each other, and from materialism, experimentally?

Documenting a child's claims in writing, independently, before any family contact with the previous personality's family is the cleanest possible design. It exists in some cases but is rare. A systematic prospective case-collection program — recruiting pediatricians to flag and document early reports — has never been formally established.

Stevenson documented 200+ cases of birthmarks or birth defects corresponding to wounds. If the correspondence is real, what mechanism could connect information about a prior wound to the developmental biology of a different fetus in a different body? No proposed mechanism exists. This is the hardest physical fact in the literature.

Most strong reincarnation cases come from South Asia, Southeast Asia, the Middle East, and indigenous cultures with reincarnation beliefs. This could mean reporting and investigation rates differ by culture — or that cultural expectation shapes which memories surface, how they're interpreted, or how they're communicated. The case distribution itself is not yet well explained.

IIT, Global Workspace Theory, Higher-Order Theories, Predictive Processing, and Orch OR all make different and sometimes contradictory predictions about where consciousness is and how it arises. A 2023 adversarial collaboration produced results somewhat more consistent with GWT, but neither theory was confirmed or disconfirmed. The measurement problem — how to detect consciousness in a system — remains unsolved.

Terminal lucidity — unexpected, sometimes dramatic cognitive clarity in patients with severe brain damage or dementia shortly before death — is documented but poorly understood. It appears to contradict the assumption that cognition is a direct function of intact neural structure. No physiological explanation has been proposed that is specific enough to test.

The question of why physical processes are accompanied by subjective experience at all remains open after 30 years of intensive philosophical work. Some argue it will eventually dissolve as neuroscience matures; others argue it reveals a fundamental incompleteness in physicalism. The answer has direct implications for whether survival of consciousness is even conceptually possible.