An electric galvanoscope played strange tricks yesterday at the Metro-Goldwyn-Mayer studios when Dr. Karl T. Waugh, dean of psychology at the University of Southern California, measured the emotions of stars and players with the psychogalvanoscope, new device of science. … Put to practical use, he explained, the machine can be hooked up in such a way as to detect audience reactions while watching motion pictures. [cont.]
Los Angeles Times (Feb. 27, 1930)