Observer Influence on Quantum Interference: Testing the von Neumann-Wigner Consciousness-Collapse Theory
Forty-seven participants selected through a worldwide three-phase recruitment for attentional expertise each received a custom optical diffraction grating apparatus and completed 10 formal half-hour sessions with alternating 30-second observe/unobserve periods. Illumination at one first-order maximum was provided as real-time feedback while a second was recorded simultaneously but never observed. Three preregistered hypotheses were not supported overall, but for one hypothesis participants with outward-focus attentional experience achieved significantly better results in reducing interference (p = 0.008). An exploratory trend analysis found progressive interference decline during observation versus the simultaneous unobserved control (p = 5.9 x 10^-14), with no such pattern during non-observation periods (p = 0.77) or in 212 control sessions run without observers.