  We present a quantum-like (QL) model in that contexts (complexes of e.g.
mental, social, biological, economic or even political conditions) are
represented by complex probability amplitudes. This approach gives the
possibility to apply the mathematical quantum formalism to probabilities
induced in any domain of science. In our model quantum randomness appears not
as irreducible randomness (as it is commonly accepted in conventional quantum
mechanics, e.g., by von Neumann and Dirac), but as a consequence of obtaining
incomplete information about a system. We pay main attention to the QL
description of processing of incomplete information. Our QL model can be useful
in cognitive, social and political sciences as well as economics and artificial
intelligence. In this paper we consider in a more detail one special
application -- QL modeling of brain's functioning. The brain is modeled as a
QL-computer.
