EFFICACY OF REPEATED PSYCHOPHYSIOLOGICAL DETECTION OF DECEPTION TESTING

Physiological measures were recorded during repeated psychophysiologic al detection of deception (PDD) tests to determine if reaction levels change with test repetition. Two groups of 22 healthy male subjects co mpleted six peak of tension PDD tests on each of two test days. A mini mum between test day interval of six days was maintained. The treatmen t group was programmed to respond deceptively to one of seven test que stions while the control group was programmed to respond truthfully to all questions. The respiration and galvanic skin resistance (GSR) lin e lengths, GSR peak response amplitude and latency, and cardiovascular inter-beat-interval (LEI) were calculated for each response. Analyses indicated that, except for GSR peak response latency, differential ph ysiological reactivity during a PDD test did not change significantly over repeated tests or days; there was a decrease in average respirati on line lengths at the initial test(s) of each day; and differential c hanges in average respiration line length, GSR peak latency. and cardi ovascular IBI responses corresponded to deception. Power analyses were calculated to assist in result interpretation. It is suggested that P DD decision accuracy, concerning:: subject veracity, should not decrea se during repeated testing.