Low-cost evoked potentials detection for brain computer-interfaces

Evoked potentials are one of the brain's electrical activity types. They appear on the human scalp as a result of a registration of an external stimulus (e.g. an appearance or a change of a sound, a flash of light or an image). Generally, they are used in medical diagnosis, but they also may be used in brain-computer interfaces. In this chapter a laboratory set for the acquisition and analysis of evoked potentials is described. The main part of this set is a photostimulator consisting of sixteen LEDs and the ATmega 328 microcontroller. The software created by the authors allows for: connection between EEG device, stimulator and computer, input stimulus control, output signal filtering and its classification. The presented set may support a process of brain-computer interface design.