One of the important lessons of brain theory is constructivism: realit
y is a pseudo-reality because the ''intuitive forms of perception'' im
plicit in the dynamics of the brain constrain reality's properties. A
cold lizard sees the world differently than a warm lizard does. Constr
uctivism has been confined to the macroscopic realm so far. A ''micros
copic'' version is proposed. Hereby the reversible microdynamics that
underlies the irreversible macro dynamics of the brain is focused on.
For simplicity a classical kinetic universe is assumed. As in macro co
nstructivism, an ''interface'' is formed which depends both on the obs
erver-external dynamics and on the dynamics that goes on within the ob
server. Due to the microscopic nature of the present dynamics, however
, its effects on the interface are incorrigible by macroscopic means a
nd therefore also not recognizable under ordinary circumstances. The m
icrodynamics in the observer is subject to effective time reversals on
a micro time scale. This is equivalent to the existence of a rapid ''
vacillation'' of observer-external causality. The spatio-temporal prop
erties of external reality are thereby nonlinearly transformed in the
interface. The predictions made by microconstructivism (or, synonymous
ly, endophysics) include a unit-action noise and nonlocality. Two unex
pected predictions are ''double'' nonlocality and rotational-frame cov
ariance. The main prediction- existence of an ''observer-relative obje
ctive reality'' - thus appears to be falsifiable.