Meditation as practiced today is almost always embedded in a spiritual context that, in most cases, can be traced back to an ancient Indian origin. Therefore, the literature deriving from that spiritual context also contains theories of meditation. Of course, such theories are not purely psychological because they have religious and philosophical content that Western scholars struggle with. Another problem is that they were mostly developed more than 1000 years ago and are often written in an “awkward” style and in languages such as Sanskrit and Pali that produce ambiguities when translated into contemporary Western languages. Nonetheless, the basis for most of these theories is as empirical as can be, as they can be assumed to be based on the experiences of what one nowadays would probably call “very experienced meditators” (e.g., Olendzki 2010; see also Batchelor’s Chapter 2 in this volume).
There have been some attempts to describe these theories for Western meditation researchers. For instance, Lutz et al. (2007) described in detail three kinds of practice recommended in a particular strand of Tibetan Buddhism and explicated hypotheses about what can be expected from each. In another attempt to make Eastern theories available to Western researchers, Grabovac et al. (2011) “translated” theoretical aspects contained in a Burmese version of Theravada Buddhism into a cognitive model. A more comprehensive approach was used by Sedlmeier and Srinivas (2015). They extracted the psychological theories of cognition from two ancient Indian thought systems: (early) Buddhism; and Sankhya-Yoga. These theories not only deal with meditation but are cognitive theories that embed meditation in a broader theoretical context. Interestingly, these theories also contain hypotheses that go beyond current Western mainstream psychology, especially concerning questions of consciousness (e.g., the assumption of “pure consciousness” that is non-intentional) and the mind-brain relationship (mind works independently of the brain).
We recommend not disregarding these Eastern explanations that stem from empirically grounded insights gathered over millennia. Instead, an attempt should be made to derive from them and to make these hypotheses (e.g., that mind is not merely an epiphenomenon of the brain but instead uses it as a tool) as precise as possible (see Sedlmeier 2014 for more examples of such hypotheses).