Micropsychology deals with the basic information-handling-mechanisms that the brain uses. Those mechanisms are genetic and they do not depend on the meaning of the handled information. The basic mechanisms that encode information, store it in associative information structures, retrieve it, implement it in mental and physical activities, and create new information from existing one are the stuff of micropsychology.
Both psychology and micropsychology strive to understand the mechanisms that underlie human behavior. Psychology's approach is top-down, or by analysis: start with a behavior, and see which sub-behaviors and mental forces cause it. Micropsychology's approach is bottom-up, or synthesis: start with the very basic elements of the brain's information processing routines, and build from them the behavior.
An ultimate goal of micropsychology is to understand all the basic physiological mechanisms that underlie the brain’s information-handling, and to show how they build all mental activities.
At this time, micropsychology can only address the operational aspects of the basic physiological mechanisms, and show how they contribute to complex mental processes. Still, micropsychology already provides important insights into major behavior patterns, and identifies targets for further neurological research.