Neuromagnetic measurements and associated modeling procedures must be capable of resolving multiple sources in order to localize and accurately characterize generators of visual evoked activity. Okada (1984) has estimated that a field pattern generated by two dipoles can be distinguished from that generated by a single dipole provided that the separation between the sources is greater than 1–2 cm, but there have been few attempts at modeling neurally generated field patterns with multiple, simultaneously active dipoles. The expanse of man’s occipital cortex is estimated to be 150–250 cm2 and invasive experiments with cats and monkeys suggest that this region most likely includes several discrete visual areas (e.g., Van Essen, 1985). It thus seems plausible that visual stimuli evoke activity from multiple discrete populations of neurons within visual cortical areas and that the application of appropriate modeling procedures to visually evoked neuromagnetic field data will resolve these populations.