THE ROLE OF GUESSING AND VERBAL RESPONSE TYPE IN PSYCHOPHYSIOLOGICAL DETECTION OF CONCEALED INFORMATION

I used a card test to study the effect of guessing on psychophysiologi cal responsivity. Results indicated that subjects who were aware of th e card they chose were more responsive to the relevant card than subje cts without knowledge of the card they were asked to guess. Psychophys iological responsivity to the guessed cards was greater than to the ne utral cards and to chance expectancy. In a verbal response type effect , the combination of the verbal response (yes or no) and the act of ly ing (no) increased differential responsivity compared with silence. I found no interaction effect between the knowledge of concealed informa tion and the type of verbal response.