ABSTRACT
Meditation of one type or another can be found in a wide variety of cultures and traced back for at least two and a half thousand years. The wide spread of popularity of transcendental meditation has been helpful since it comprises a simple, rapid, highly standardized training procedure which readily lends itself to experimental investigation. The responses to meditation are most readily subdivided into psychological, physiological, and chemical. Phenomenological changes are of special interest since they represent the very raison d'etre for meditation. The study of the temporal characteristics of meditation involves several dimensions. One ancient division has been between three categories of meditation: concentrative, receptive, and combined. In accordance with Western research paradigms, most work has focused on the more easily and objectively measured behavioral parameters even though the aim of meditation is primarily phenomenological. Evolutionary model represents a specific application of a more general stimulus response model of the evolution of research.
