…in modern psychological and medical laboratories with what is called limited environment. For example, people like Hebert McGill and Dr. Lilly at the National Institute of Health in Washington have employed various means for cutting down the input of sensory…

…interesting facts here is that the great majority of these visions were extremely unpleasant. They were so unpleasant that I've asked Dr. Lilly what they were. And he has always declined to tell me. I don't know what... They must have been very unpleasant…