Putative perception of rotating permanent magnetic fields following ingestion of LSD

While sitting alone in complete darkness, 3 participants who had ingested psychotropic concentrations of lysergic acid diethylamide reported diffuse blobs of white, purplish, or greenish-yellow lights as two horseshoe magnets rotated at 0.5 Hz. The experiences were not reported when the magnets were stationary or removed from the apparatus. The estimated peak-to-peak variation in field strength at the distance of perception was between 50 and 500 nanoTesla. An association between these results and possible ergot-induced perceptions of "magnet light" reported during the last century by von Reichenbach (1851) is suggested.