Orthodox science says that the brain is the organ of the mind, but esoteric science says the brain is the organ of perception of sense impressions and co-ordination of efferent impulses. It is the telephone exchange of the nervous system. It is only one of the points where mind touches body, the others being the ductless glands of the endocrine system, the pineal, pituitary, thyroid, adrenals, thymus and gonads; to which may be added the Solar Plexus and Sacral Plexus.
Carl Sagan described the three tiers of the human brain as the reptilian (the most ancient and deepest layer), the limbic (the middle tier that directs motor sensory and normal life functions), and the neocortex (the uncharted territory of the upper realms). He also used the symbolic dragon to portray the dormant, sleeping, reptilian part of the brain that is both ancient and undisturbed. When the sleeping dragon rises, his fire (kundalini) surges throughout the various layers and in alchemical measures awakens and integrates the triune brain.
Once you've understand that everything is energy and your brain is nothing more than a decoder then you have a good chance to understand what you really are. Call it soul or spirit - you decide at what frequency your soul operates. Know you and know what your eyes can't see.