[Truth curves on soot blackened paper--apparatus-supported lie detection in Graz in the 1920s]

In the 1920s, experiments with apparatus-supported lie detection and registration of expression were conducted at the Criminological Institute of the University of Graz in order to establish a sound methodological basis for testimony research. For this purpose, the criminologist Ernst Seelig used a method of lie detection developed by the psychologist Vittorio Benussi, which focuses on the analysis of breathing. Benussi had stated that the expiration after telling a lie was faster than after telling the truth, but Seelig could not verify this rule in forensic practice. Consequently, this method of lie detection was of no practical use for criminology. Seelig also carried out experiments with the method of registration of expression developed by the psychiatrist Otto Lowenstein. He registered the examinee's thoracic and abdominal breathing and the movements of the extremities with the help of a kymograph. By interpretation of the curves recorded on soot blackened paper, conclusions concerning the mental elements of an offence as well as the existence of certain dispositions and of amnesia should have been made possible. Seelig was convinced of the efficiency of this method. These experiments can be regarded as early attempts at finding not only simple facts but also answers to quasi-metaphysical questions concerning the "true nature" of man with the help of methods based on natural science and modern technology. Thus they are precursors of present-day neuroscience and neuro-imaging.