This study explored the hypothesis that in some cases intuitive knowledge arises from perceptions that are not mediated through the ordinary senses. The possibility of detecting such nonlocal observation was investigated in a pilot test based on the effects of observation on a quantum system. Participants were asked to imagine that they could intuitively perceive a low-intensity laser beam in a distant Michelson interferometer. If such observation were possible, it would theoretically perturb the photons’ quantum wave functions and change the pattern of light produced by the interferometer. The optical apparatus was located inside a light-tight, double-steel walled, shielded chamber. Participants sat quietly outside the chamber with eyes closed. The light patterns were recorded by a cooled digital camera once per second, and average illumination levels of these images were compared in counterbalanced mental blocking versus nonblocking conditions. By design, perturbation would produce a lower overall level of illumination, which was predicted to occur during the blocking condition. Based on a series of planned experimental sessions, the outcome was in accordance with the prediction (z 2.82; P .002). This result was primarily due to nine sessions involving experienced meditators (combined z 4.28; P 9.4 106 ); the other nine sessions with nonmeditators were not significant (combined z 0.29; P .61). The same experimental protocol run immediately after 15 of these test sessions, but with no one present, revealed no hardware or protocol artifacts that might have accounted for these results (combined control z 1.50; P .93). Conventional explanations for these results were considered and judged to be implausible. This pilot study suggests the presence of a nonlocal perturbation effect that is consistent with traditional concepts of intuition as a direct means of gaining knowledge about the world, and with the predicted effects of observation on a quantum system.