Shepard and Chipman's second order isomorphism describes how
the brain may represent the relations in the world.
However, a common interpretation of the theory can cause difficulties.
The problem originates from the static nature
of representations. In an alternative interpretation, I propose that
we assign an active role to the internal representations and
relations. It turns out that a collection of such active units can
perform analogical tasks. The new interpretation is supported
by the existence of neural circuits that may be implementing such a function.
Within this framework, perception, cognition, and motor function
can be understood under a unifying principle of analogy