Topographical characterization of normal visual evoked responses

A study of visual evoked responses in a normal population was carried out using a high-precision programmable stimulator and an innovative brain mapping system which presents the overall activity on a three dimensional surface representing the human head. The interpolation method used gives a more precise computation of the potential value between electrodes. Two normal distributions of visual responses are presented which were identified while trying to topographically characterize visual evoked responses in order to construct a comparative data base. The proposed classification of two normal groups was verified by means of a statistical topographic analysis with the significance probability mapping technique.