Effect of visual feedback and application of skin potential response to detection of deception

Abstract

In view of a possible theoretical formulation that the factor which produces the physiological response is not lying or guilt per se but rather something relative to the consequences of being detected, the information, which subjects perceive as to their detectability of deception when confronted with a device and test process, may be expected to play a major role in determining the results of detection.Thus, a motivational set plus continuous or immediate feedback from the activity of the autonomically influenced peripheral effector provides appropriate information concerning the lie detection situation, convincing the subjects that they will not be able to successfully deceive. Since the feedback the autonomic response via visual display was suggested to enable the subjects to modify their responses according to their motivation, it was preliminaly demonstrated that voluntary control of the skin potential response (SPR) with watching a visual display could not effectively prevent detection in the experimental situation where subjects were required to mask all his responses rather than responding voluntarily to wrong items. Then, a total of 30 college students participated in a detection of deception experiment designed to determine the effect of visual feedback from subjects own responses on the rates of detection, together with the feedback effect of psuedoresponses artificially induced. One of five cards was selected by each subject, and the SPR to the selected card was compared with the responses for (nonselected) cards in each of the 3 groups, consisting of 10 subjects. Subjects were motivated to deceive and withhold this response by means of the previous instructions which told the subjects that individuals with a great emotional control and superior intelligence were able to deceive successfully. One experimental (Feedback) group was provided with continuous visual feedback of their own SPR. The other experimental (feedback with psuedoresponse) group also received continuous feedback but was given a psuedo-response artificially induced for the first critical item. A control (Non-feedback) group received no feedback.The SPR used in all three groups were consistently found to discriminate deceptions better than by chance. As predicted, the results obtained from subjects who received feedback with psuedo-response were significantly superior in efficiency in discriminating deception to those of feedback group, and the lowest detection rates were found with non-feedback group. The feedback procedures were also found to yield some evidence to heighten the subject's autonomic reactions, and accordingly, the SPR's under the feedback procedures were free to some degree from an adaptation effect despite the successive presentation of items.In addition, the SPR produced more frequently diphasic wave-forms accompanied with large positive deflections to the critical items as opposed to the noncritical items. The findings conform to the “consequences theory of detection of deception” and suggest that the feedback procedure from the subjects' own record is a useful activation technique with which to drive the detection of deception.Furthermore, the use of the SPR may be recommended as a valuable indicator in detection of deception.