The concept of altered states of consciousness and its problematic nature

The study of altered states of consciousness as a group of similar phenomena began about 60 years ago, and is now a significant part of contemporary studies of consciousness. Since the definition of consciousness remains a problem for modern science, this article raises the question of how to understand altered states of consciousness (ASC) without solving the problem of consciousness itself. This understanding becomes possible via the problematization of the philosophical concept of ASC: do we use it to describe one phenomenon, a group of similar, or rather different phenomena? In other words, the question is whether the concept of altered states of consciousness is just an «umbrella concept» or all these states have something in common. Answers to these questions could be found through searching for key characteristics that are common to all conditions related to altered states of consciousness. To solve this problem, we provide two possible solutions: 1) to find and examine the parameter characterizing ASC in terms of their novelty and uniqueness; 2) to find characteristics common to different ASC in their descriptions taken from various theories. The first solution involves using the data on the orienting reflex, while the second way leads us to distinguishing at least three parameters: 1) emotional evaluation, 2) activation, and 3) the content and structure of speech. These solutions could be verified empirically, and future research is expected to broaden our knowledge about altered states of consciousness.