Polygraph machines sense changes in glucocorticoid (hormone) levels, which initiate chemical reactions such as changes in respiration, heart rate and skin conductance (a moisture buildup under skin). Thus, a polygraph measures physiological changes when under the stress of questioning. That questioning is intended to determine whether a person is lying or being truthful. EyeDetect measures
Each test consists of an introduction, a practice test, and then five sessions of 48 true or false statements. Questions related to two issues are asked, as well as neutral questions. The same questions are repeated in a randomized order during the five sessions, and these sessions are separated by four sessions of alpha arithmetic-based
Simply stated, polygraph tests that cover multiple issues (not related to a specific incident) may show substantially reduced accuracy and efficiency. The risk of error ¬increases to the extent that the test includes a number of separate issues that can be independently answered truthfully or deceptively. Such tests are problematic when the individual is truthful
While reading a computer-based series of questions, EyeDetect measures an examinee’s response accuracy, response time, pupil diameter, reading behavior and blink rates. The results are consistent with the cognitive workload hypothesis.Observations include:Guilty individuals — when compared to innocent individuals and while responding to simple test statements — make more errors, take longer to respond, make