Abstract
Heart rate (HR) responses were analyzed in twenty field polygraph records for the guilty person paradigm using the paired control question technique (CQT) to detect deception, including 60 relevant and control questions. All outcomes as to whether the subjects were deceptive or truthful were verified since the 10 deceptive subjects were convicted of their charge (D-context) and the remaining 10 truthful subjects were acquitted of their charge (T-context). The ratio of HR during the question period (Q-p) and during the answer period (A-p) to the prestimulus HR (the five beats before question onset) cinstituted the index of HR change to each question.
Tonic HR increased in D-context as compared to T-context. The phasic HR accelerated significantly during Q-p to the relevant and control questions in D-context and during Q-p to the relevant question in T-context, while no significant change of HR was demonstrated during A-p to the relevant and control questions in both contexts. These results indicate that tonic HR responses can have an important role in discriminaing deception and truthfulness in a field situation. However, phasic HR change has no apparent relation to the relevant question in field CQT. These findings suggest that HR change derived from attentive processes of subject's set may be important in the detection of deception for a field population.
