One religious practice sometimes found in Heathenry is "seiðr", which has been described as "a particular shamanic trance ritual complex", although the appropriateness of using "shamanism" to describe "seiðr" is debatable. Contemporary "seiðr" developed during the 1990s out of the wider Neo-Shamanic movement, with some practitioners studying the use of trance-states in other faiths, such as Umbanda, first. A prominent form is high-seat or oracular "seiðr", which is based on the account of Guðriðr in "Eiríks saga". While such practices differ between groups, oracular "seiðr" typically involves a "seiðr"-worker sitting on a high seat while songs and chants are performed to invoke gods and wights. Drumming is then performed to induce an altered state of consciousness in the practitioner, who goes on a meditative journey in which they visualise travelling through the world tree to the realm of Hel. The assembled audience then provide questions for the "seiðr"-worker, with the latter offering replies based on information obtained in their trance-state. Some "seiðr"-practitioners make use of entheogenic substances as part of this practice; others explicitly oppose the use of any mind-altering drugs.