This paper reviews the aspects of cognitive science that relate best to using electrical and magnetic recording to understand the function of brain systems. It outlines a framework for relating cognitive activities of daily life (typing, reading) to underlying neural systems. The framework uses five levels of analysis: task, elementary operations, components facilitation and inhibition, neural systems, and cellular level. Evidence is outlined which supports the idea that component facilitations and inhibitions in performance can be systematically linked to the activity of neural populations. The evidence is in the area of spatial attention and uses results of normal and brain injured subjects as well as data from surface electroencephalography and recording of single cells during selective attention tasks. (Author)