P300 is a brain wave derived from the electroencephalogram (EEG), which has recently been used as a novel information channel in the detection of deception. The traditional channels are recorded from the autonomic nervous system and include physiological activity such as respiration pattern, blood pressure, and skin conductance. In contrast, the EEG is a record of sequential, spontaneously changing voltages as a function of time, recorded from the scalp surface in humans. It reflects the spontaneous activity from the underlying cerebral cortex. If as these changing voltages occur, a discrete stimulus event (such as a light flash) occurs, the EEG breaks into a series of somewhat larger peaks and troughs, called components. This series of waves is called an event-related potential (ERP).

These early peaks and ...