Just think about our most ordinary activities, such as alternating sleep and wakefulness, when we are more tired, the state of daydreaming, or those activities we do in automatic mode. Still, we can also have peak experiences, for example, as a result of making love or some cathartic experience. So, some degrees exist between fully attentive conscious awareness and the most profound meditative state, or trance.
THE HARD PROBLEM
What is "consciousness"? To formulate what consciousness is, we must first turn to those philosophical studies of consciousness, which also question the knowability of consciousness, and the decision of which is called a "difficult problem". A fundamental question is whether something can exist that can only be seen by itself, from the inside, through the subjective observer.
We all experience our feelings from the inside; our experiences are organized in a unique pattern, the network of our thoughts and the imprints of our perception in a complex order (or disorder:)) form the internal system that connects us to the outside world. Can this completely subjective system be approached objectively? Several schools of thought are trying to find an answer to the question, and all of them are somewhat right. It is also possible that consciousness in itself cannot be known objectively. That is why the changes in the state of consciousness are so important, during which some similarity or identity can be found in the changes of consciousness that are different at the level of the subject, from which it is possible to infer its functioning.
THE PHYSIQUE
The other direction of consciousness research, starting from the direction of physical reality, the body, and the brain, examines the traceable signs of changes in consciousness with various medical devices. EEG, MRI, and PET all measure some physical quantity, either the essential electrical activity or a change generated by some physical influence. These tools are generally used to map sleep and meditative states, which are more difficult to separate but still altered states of consciousness.
What is the basis on which these states can be distinguished? They differ in different modalities of perception and self-perception, i.e. we perceive space and time, visual and auditory stimuli, our own body, and our identity differently, and we leave different bandwidths for the presence of the outside world, which also changes our attention capacity. Based on these, we can separate sleep from being awake, dreaming consciousness, or lucid dreaming. These parameters change in hypnosis or trance and in different stages of meditation.
STATES OF MIND
Why is it important to know these? Ken Wilber writes in his book The Integral View (Ursus Libris, 2008) that "the three natural states of consciousness - waking, dream and deep formless sleep - can be a small treasure chest of spiritual wisdom - if we know how to use them correctly." trans. Bence Gánti) According to Wilber, these states of consciousness can contain the entire spectrum of spiritual enlightenment. If we look at its everyday, practical usefulness, of course, it is not the fact of enlightenment itself that can help us but the path leading to it, which can illuminate the dark spots behind our problems that have been going on for years. So, knowing the states of our consciousness can be very useful in acquiring knowledge with which we can "consciously" migrate from one to another.
How can a state of consciousness become healing? "Trance is a natural, everyday experience. Allow yourself to see what you don't allow yourself to notice." (M.H.Ericson) So the process in which we make efforts to modify the conscious mind (and here I do not mean taking pills, liquids and smokes), i.e. we do not only benefit from the changes that occur spontaneously (the Freudian dream work of the dream, the contents suppressed in the unconscious meaning the process of its processing here), can already have healing power in itself, since we are actively doing something with ourselves, for ourselves. The bonus is that by moving away from the awake state and paying attention to our inner self, we can tune in to our deepest wisdom, get answers to our questions, find the root of our physical or mental ailments, uncover their cause, and create the most effective remedy available at the moment. Somehow, in this process, we can change, whether it is self-made meditation or therapist-led hypnotherapy.