The past is not complete but can be changed; present actions can change both the future and the past.

For Question 1: approximately 600 participants would first encode a videotaped event and provide an initial memory report, with records immediately and securely archived across institutions. After 24 hours, an independent system would randomly provide positive, negative, or neutral feedback. Memory, confidence, and source judgments would be assessed on days 2 and 7, with automated administration and blinded testers and analysts. Changes in subsequent reports can test only memory reconstruction. To test retroactive influence, conduct a separate experiment with approximately 10^5 trials in which intervention targets are randomly assigned only after existing outcomes have been securely archived, testing pre-registered associations between earlier outcomes and later randomized interventions. The project would take 6–12 months. Even an established association would not demonstrate that the same historical record had been rewritten.

Post-Event Feedback and Memory Updating: A Pre-registered Study With Independently Archived Baseline Records

If present interventions actually alter objective events that have already occurred, this would overturn the causal assumption that established facts about past macroscopic events are unaffected by subsequent interventions.

Elizabeth F. Loftus，University of California, Irvine，误导信息与记忆研究; Ken B. Wharton，逆因果理论; Zoltan Kekecs，预注册异常认知重复研究

If “changing the past” means changing objective events, the claim is indeed stronger than memory reconstruction and distinguishable in principle. If it means only changing the meaning of the past or current memories, it adds no new predictions.

“contradicted” applies to the literal version in which objective macroscopic history can be rewritten, which conflicts with the conventional causal framework of physics. If all records and memories are also claimed to be rewritten without a trace, the claim loses testability. Positive feedback does not automatically constitute the recovery of accurate memories.