Preferably, an embodiment of an apparatus includes at least a plurality of sensor assemblies, wherein each sensor assembly provides at least one electrically responsive surface, and an oscillation device communicating with the sensor assembly. Preferably, the sensor assembly includes at least a signal processing circuit in electrical communication with the oscillation device to selectively agitate the at least one electrically responsive surface. The preferred apparatus further included a brainwave processing system communicating with each of the plurality of sensor assemblies, and a ground reference interacting with the brainwave processing system, wherein a selected one of the plurality of sensor assemblies provides a reference signal for each of the remaining sensor assemblies, and in which each electrically responsive surface is in pressing contact with a cranium of a subject.