There were many early attempts to build a lie detector, but in the end, scientists don't really believe they work well enough to be trusted.
- In 1885 Cesare Lombroso developed a machine used to measure changes in blood pressure for police cases.
- In 1904 a device by Vittorio Benussi was used to measure breathing.
- Sir James Mackenzie of Scone, Scotland invented an early lie detector or polygraph in the 1900s. His machine "could be used to monitor the cardiovascular responses of his patients by taking their pulse and blood pressure".
- In 1911 a device recording both blood pressure and galvanic skin response was invented by Dr. Reginald A. Larson of the University of California.
- In the 1920s William Marston made a device that used blood pressure and galvanic skin responses.
- In 1936 the Berkeley Psychograph, a blood pressure-pulse-respiration recorder was developed by C. D. Lee.
- In 1945 a device which recorded muscular activity accompanying changes in blood pressure was developed by John E. Reid.
