For this reason, the ethnographer should learn to discern shifts in states of consciousness in informants and ascertain what, if any, ritual activity has been positioned so as to mediate the change of their internal state. Rituals are often symbolically rich events. Moreover, rituals frequently incorporate a variety of drivers that may account in some measure for the rituals' efficacy. Drivers are ritual elements that evoke specific neurophysiological effects. They may be fairly gross in their form, such as drumming, dancing, injestion of psychotropic drugs, sweat baths, stressful ordeals, flickering lights, chanting, fasting, special diets, etc., or they may be relatively subtle in form, such as intense concentration upon the breath, upon eidetic imagery, or upon a burning question.
Drivers are very often universal in their essential form.
The ethnographer should also be aware that while a ritual activity may be a necessary condition for an intended experience, and perhaps even include a profusion of drivers, it is unlikely to be a sufficient condition. A ritual is a totality that is itself an element in a greater play. A ritual is part of a whole, a context. There will be other ingredients required to evoke the intended experience. For example, one may repeat a meditation many times without reaching the intended goal, because perhaps one of the requisites for the intended experience may be a certain level of tranquillity.