found that the National Reconnaissance Office was possibly breaching ethical and legal boundaries by encouraging its polygraph examiners to extract personal and private information from US Department of Defense personnel during polygraph tests that purported to be limited in scope to counterintelligence matters. Allegations of abusive polygraph practices were brought forward by former NRO polygraph examiners. Alternative tests Most polygraph researchers have focused more on the exam's predictive value on a subject's guilt. However, there have been no empirical theories established to explain how a polygraph measures deception. A 2010 study indicated that functional magnetic resonance imaging (fMRI) may benefit in explaining the psychological correlations of polygraph exams. It could also explain which parts of the brain are active when subjects use artificial memories. Most brain activity occurs in both sides of the prefrontal cortex, which is linked to response inhibition. This indicates that deception may involve inhibition of truthful responses. Some researchers believe that reaction time (RT) based tests may replace polygraphs in concealed information detection. RT based tests differ from polygraphs in stimulus presentation duration, and can be conducted without physiological recording as subject response time is measured via computer. However, researchers have found limitations to these tests as subjects voluntarily control their reaction time, deception can still occur within the response deadline, and the test itself lacks physiological recording. History Earlier societies utilized elaborate methods of lie detection which mainly involved torture. For instance, in the Middle Ages, boiling water was used to detect liars, as it was believed honest men would withstand it better than liars. Early devices for lie detection include an 1895 invention of Cesare Lombroso used to measure changes in blood pressure for police cases, a 1904 device by Vittorio Benussi used to measure breathing, the Mackenzie-Lewis Polygraph first developed by James Mackenzie in 1906 and an abandoned project by American William Moulton Marston which used blood pressure to examine German prisoners of war (POWs). Marston's machine indicated a strong positive correlation between systolic blood pressure and lying. Marston wrote a second paper on the concept in 1915, when finishing his undergraduate studies. He entered Harvard Law School and graduated in 1918, re-publishing his earlier work in 1917. Marston's main inspiration for the device was his wife, Elizabeth Holloway Marston. "According to Marston’s son, it was his mother Elizabeth, Marston’s wife, who suggested to him that 'When she got mad or excited, her