While some interesting and highly original works of art have been produced during the acid high, the creative effects of LSD cannot be measured solely in terms of immediate artistic output. Even more important is the enlargement of vision, the acute awareness of vaster potentials that persists long after the drug has worn off. Janiger's subjects frequently commented on the affinity between the drug-induced state and "what they felt might be an essential matrix from which the imaginative process derives." Author William Burroughs, who experimented with hallucinogens on his own, agreed with this assessment: "Under the influence of mescaline I have had the experience of seeing a painting for the first time, and I found later that I could see the painting without using the drug. The same insights into music or the exposure to a powerful consciousness-expanding drug often conveys a permanent increase in the range of experience. Mescaline transports the user to unexplored psychic areas, and he can often find the way back without a chemical guide."