Microcomputer-based scalp topography mapping of event-related potentials

A microcomputer-based technique to evaluate the scalp topography of event-related potentials is described. This technique uses only four electrode locations and produces a 24 × 24 element color matrix of the topography of scalp electrical activity across time. The program also displays the coordinates, latency, and value of the maximum point within the matrix. The program is implemented on an Apple II+/IIe computer and is adaptable to other computers with graphic capabilities.