By the same token, the
Gestaltists emphasized the
relations of elements as the
basis of other kinds of
perceptual phenomena. As we
shall see, the Gestaltists argued
that the preservation of such
relations in the face of certain
absolute changes in stimulation
could account for constancy as
well as for various illusions.

    Underlying these
psychological principles were
thought to be brain processes
unlike those in which impulses
travel only along neuron
pathways. Rather, the brain was
thought of as a solid electrical
conductor in which currents
spread through the tissue along
paths of least resistance. Thus,
when asked why the world looks
the way it does, the Gestaltist
gives an answer that is quite
different from that of the
Helmholtzian. To the Gestaltist,
our perceptions are the result of
spontaneous interactions in the
brain to which sensory
stimulation gives rise; to the
Helmholtzian, they are the
result of the unconscious
interpretations we make of
sensations, based on past
experience.