The goal of the paper is to clarify the nature and mechanisms of funct
ioning of human consciousness. It is assumed that the main specific fe
ature, which distinguishes consciousness from other brain subsystems,
is its ability to observe the content of its own memory. It demonstrat
es that cyclic information run in distributed neural structures with f
eedbacks may serve as a fundamental physiological mechanism of an inne
r scanning (awareness) system for information coming from outside. The
area of location of consciousness in the brain is determined as a set
of neural structures involved in cyclic information run processes. It
is ascertained that the rehearsal procedure is a basis operational me
ans of discursive thinking, imagination and reflexion.