“Putative Perception of Rotating Permanent Magnetic Fields following Ingestion of LSD”, 1998-10-01 ():
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 nano-Tesla.
An association between these results and possible ergot-induced perceptions of “magnet light” reported during the last century by von 1851 is suggested.