Theories of NDE include spiritual theories which presume that consciousness has an independent existence with a belief in after life. Blackmore described that sometimes mind can acquire a mental model of reality assumed upon imagery and memory instead of sensory impressions. A mental state that may be intrinsically quite different from a veridical perception might come to be mistaken for so, and hence gets the status of a hallucination. However, 'mathematical models' of 'parallel universe' in quantum physics mimic 'experiences' of these patients