Psychedelic experience sources of some psychedelic drugs such as ayahuasca and mescaline-containing cacti are sometimes referred to as "plant teachers". Similarly, in a follow-up to the psilocybin and mysticism study at Johns Hopkins, researchers observed that psilocybin: "occasions personally and spiritually significant mystical experiences that predict long-term changes in behaviors, attitudes and values". Psychedelic experience includes the full range of mystical or religious experiential phenomena. Two scientific studies have concluded that psilocybin (a typical psychedelic compound that occurs naturally in psilocybin mushrooms) reliably triggers mystical-type experiences. The more recent study at Johns Hopkins University identified mystical experiences by means of several questionnaires
Dissociative accompanied by actual loss of consciousness." Both Pender (1970) and Johnstone et al. (1959) reported that patients under anaesthesia due to either ketamine or phencyclidine were prone to purposeless movements and had hallucinations (or "dreams") during and after anaesthesia. Some patients found the hallucinations euphoric while others found them disturbing. At sub-anesthetic doses, dissociatives alter many of the same cognitive and perceptual processes affected by other hallucinogenic drugs such as mescaline, LSD, and psilocybin; hence they are also considered hallucinogenic, and psychedelic. Perhaps the most significant subjective differences between dissociatives and the classical hallucinogens (such as LSD and mescaline) are