  For two decades, the formalism of quantum mechanics has been successfully
used to describe human decision processes, situations of heuristic reasoning,
and the contextuality of concepts and their combinations. The phenomenon of
'categorical perception' has put us on track to find a possible deeper cause of
the presence of this quantum structure in human cognition. Thus, we show that
in an archetype of human perception consisting of the reconciliation of a
bottom up stimulus with a top down cognitive expectation pattern, there arises
the typical warping of categorical perception, where groups of stimuli clump
together to form quanta, which move away from each other and lead to a
discretization of a dimension. The individual concepts, which are these quanta,
can be modeled by a quantum prototype theory with the square of the absolute
value of a corresponding Schr\"odinger wave function as the fuzzy prototype
structure, and the superposition of two such wave functions accounts for the
interference pattern that occurs when these concepts are combined. Using a
simple quantum measurement model, we analyze this archetype of human
perception, provide an overview of the experimental evidence base for
categorical perception with the phenomenon of warping leading to quantization,
and illustrate our analyses with two examples worked out in detail.
