CONTINGENT NEGATIVE-VARIATION (CNV) IN TH E DETECTION OF DECEPTION TASK USING A SERIAL PRESENTATION OF PICTURES

The purpose of the experiment was to investigate the feasibility of us ing contingent negative variation (CNV) as an index of detection of de ception. Twelve subjects were required to complete both an innocent an d a guilty condition in that order. In the innocent condition, a serie s of six pictures, two of which depicted different landscapes and four others which depicted different female faces, was presented repeatedl y on a computer display. Subjects responded by pressing a button follo wing the landscape picture (target stimulus) that was presented last i n the sequence. In the guilty condition, the procedures were the same except that subjects were also required not to detect one of the femal e pictures in mind (critical item), which they had chosen after the co mpletion of the innocent condition. As compared with the innocent cond ition, the CNV amplitudes decreased significantly immediately before t he target stimulus in the guilty condition where subjects had to conce al the critical item. The implication of these data both for the psych ological completion of the concealed task and the practice in the fiel d were discussed.