The self-inflicted pain countermeasure of biting the tongue and pressing the toe on a tack were incorporated into a series of peak-of-tension (POT) tests comprised of 30 separate charts. For each test, two subjects were examined, and three charts for each were produced. The same two subjects were used for each test. On the first chart, no countermeasures were used; the second chart incorporated the countermeasure of tongue biting; and the third chart involved the examinee's pressing a toe on a tack at a predetermined padding question. All examinations were conducted on a Lafayette four-channel electronic polygraph model #76475-G. Apparently the countermeasures used could be effective in a control-question test if the subject were to inflict pain at the control question. The countermeasures used are particularly difficult to detect by the examiner, since they do not require much movement by the subject. A field study is required, however, to determine whether these countermeasures could be effective in an actual polygraph examination. Charts, 35-item bibliography, and 2 abstracts.