The effect of perimetric stimulation on evoked potential distribution--a theoretical model.

A schematic cortical projection of the human visual field is combined with the concept of dipole planar generators to provide a theoretical model of the scalp distribution of evoked potentials from visual field stimuli. The computations illustrate the importance of gyral surfaces as the principal generators of recorded evoked potentials. Taking several zones of the visual field projection on the striate area as an example, the model is used to produce horizontal profiles of evoked potential amplitude. This indicates the limitation and possibilities of mapping the cortical projections in man and relating these to perimetric findings.