NCJ Number
207601
Journal
Polygraph Volume: 33 Issue: 3 Dated: 2004 Pages: 143-155
Date Published
2004
Length
13 pages
Annotation
This study examined the feasibility of adding the measurement of changes in facial skin surface temperature to the traditional measures of physiological changes in the course of a polygraph examination.
Abstract
A total of 25 U.S. Army basic trainees between the ages of 19 and 28 were given polygraph examinations that measured respiration, relative blood volume, and electrodermal activity. In addition, a Raytheon model FPA thermal imaging radiometer was used to measure skin surface temperature (SST). Prior to the examination, 12 participants were instructed to commit a mock crime in a room staged for the study. They were told to stab a plastic dummy with a screwdriver present at the scene and then steal $20 from a purse next to the dummy. They were then instructed to lie to the polygraph examiner about what they had done. The remaining 13 participants were unaware that others were committing the crime and were classified as the nondeceptive group. The polygraph examiner did not know who belonged to which group (deceptive or nondeceptive). The frequencies of accurate determinations using traditional polygraph measures, SST measures, and a combination of Polygraph and SST measures were compared by using binary logistic regression. The highest accuracy was achieved by using a combination of polygraph and SST measures. These findings are discussed in relation to orienting response theory, which proposes that decreases in cephalic blood volume reflect a defensive response that protects the organism from harm; whereas, novel or unexpected stimuli produce increases in forehead blood volume that reflect an orienting response that improves perceptual ability. 2 tables, 2 figures, and 29 references