In Western psychological parlance it would be called sensory deprivation: sitting alone for days in a light- and sound-free space with only the essentials for living. In traditional Tibetan culture, and increasingly in American Buddhist communities, this common practice is called a Dark Retreat. Psychologist and longtime Tibetan Buddhist practitioner Martin Lowenthal is uniquely qualified to reshape this traditional Tibetan practice to fit the Western lifestyle. His own journal of a monthlong Dark Retreat is included.