Two international experiments attempted to replicate a controversial precognition study by Daryl Bem. The experiments reversed the usual cause-effect sequence: participants responded to stimuli before a prime appeared, testing whether response times would be longer for incongruent stimuli. The preregistered confirmatory hypothesis was not supported in either experiment. Exploratory analyses in Experiment 1 found a significant effect only among English-language participants, not those using translations.
A replication of the Hall experiment tested whether a quantum event is physically real only when consciously observed. The delay between a pre-observer and a final observer viewing the same event was extended to 1 second, and the final observer's early brain responses (EEG) were measured before they became conscious of the event. Significant differences in brain responses occurred depending on whether the pre-observer looked at the quantum event, supporting the 'subjective reduction' interpretation. Alternative normal explanations were considered and rejected, and the authors conclude that further research is warranted.