00:00 The episode is about lie detectors and how they were first used in the 1920s by a police officer named John Larson.

04:04 The first time a polygraph was used to solve a crime was in the case of Helen Graham, where her sudden rise in blood pressure followed by a confession led to her being caught.

07:57 Lie detectors measure physiological changes, such as changes in respiratory rate and sweating, in order to detect fear and determine if a person is guilty or not.

11:33 Lie detectors have not changed much in the past 100 years and still rely on measuring physiological changes such as breathing, heart rate, blood pressure, and skin conductivity to determine if a person is lying, but these measurements are subjective and considered by many to be "voodoo science."

15:29 Polygraph examiners can open up shops and practice without any accreditation or licensing, but there are programs, like the Exiton Academy, that offer training and require completion of a 10-week course and submission of 25 real-life polygraph examinations for review in order to become a licensed forensic psychophysiologist.

19:18 The polygraph test analyzes data to determine if a person is deceptive or not, comparing their responses to control questions and questions related to the investigation.

23:03 Polygraph tests are only admissible in court in New Mexico, and even then, their validity is questionable due to subjectivity and the potential for false positives and false negatives. The federal government is the largest consumer of polygraph exams, but the use of MRI technology as a lie detector is gaining traction, although it is still in the early stages and raises moral and ethical concerns. Another potential lie detection method is penile plesimography, which measures changes in contraction and girth.

26:47 Penile plesimography is used to detect arousal and has been used in a study to determine if homophobic individuals become aroused when exposed to homosexual pornography.