In the shadowy recesses of French and Spanish caves, the weathered confines of South African and North American rock shelters, and the dank innards of massive Irish stone tombs, ancient shamans and their otherworldly visions are coming back to life. This is no tale of literal resurrection, nor is it a development likely to inspire an episode of television's X-Files. Instead, the case of the revived shamans is the latest chapter in scientists' efforts to wring meaning from painted and etched images rendered by people who lived as many as 33,000 years ago. Growing numbers of researchers now theorize that the art adorning caves, rock shelters, and even burial sites frequently depicts the trance-induced, supernatural journeys of shamans. Historical accounts of many hunter-gatherer and foraging groups include descriptions of shamans who periodically conduct rituals that they believe allow them to travel to parallel worlds set out in local belief systems. In these realms, dead ancestors, deities, and various fearsome creatures await the shaman, who deals with them in ways intended to make rain, heal the sick, and meet other vital community needs. In preparation for their otherworldly commutes, shamans typically take steps to induce trances. techniques include dancing, isolation in dark places, rapid breathing, or the ingestion of hallucinogenic plants. In the first stage of a trance, the shaman perceives any of a handful of basic geometric forms. shapes are brought to mind automatically by brain processes that facilitate altered states of consciousness and form the basis of shamans' supernatural visions, according to proponents of the neuropsychological model of rock art. After coming out of the trance, shamans artistically recreate their visions, both as memory aids for later ritual travels and as portals through which they pass into the spirit world, these scientists propose. Rock art in South Africa, as well as art in a number of other parts of the world, has been, in large measure, closely associated with the trance experiences of shamans, contends archaeologist David Lewis-Williams of the University of the Witwatersrand in Johannesburg, South Africa. These paintings were powerful ritual objects, not just pictures. This view-which first attracted international attention when Lewis-Williams and Thomas A. Dowson of the University of Southampton in England presented it in the April 1988 CuRRENT ANTHROPOLOGYsparks plenty of controversy, particularly among archaeologists who doubt that anyone can decipher the original meanings of prehistoric artworks. LewisWilliams considers it a crucial theoretical advance. Support for Lewis-Williams' view now comes from influential quarters. For instance, archaeologist Jean Clottes, scientific adviser for prehistoric art at the French Ministry of Culture in Foix, has joined the South African researcher in an investigation of a dozen prehistoric caves in France and Spain. They plan to document the presence of images linked with altered states of consciousness and shamans' rituals. We'll probably get a lot of flak, especially from French prehistorians, Clottes asserts. But it looks to me like people produced many works of art in these caves as a means of traveling to a supernatural world.