Psychophysical Examinations with the Galvanometer and the Pneumograph in Normal and Mentally Ill Patients

Originally published in English in the "Journal of Neurology" in London in 1907, this edition has been updated into modern English for readability. In addition to the modern and readable refresh, this edition includes an illuminating afterword by the translator, offering critical reflections on the context, philosophical underpinnings, and continuing significance of Jung's ideas. In addition to providing clarity for contemporary readers of this particular work, the afterword situates the work within the broader arc of Jung's philosophy and explains this early clinical work in context. Accompanied by a timeline of Jung's life and work and other supplementary material, this edition contextualizes the theories within his personal, cultural, and historical milieu, providing an indispensable guide for both newcomers and seasoned scholars of Jungian psychology. This new translation aims to make these early scientific works of Jung's (written for academics) accessible to today's modern reader by removing the academic references and using clear, simple diction and syntax.

Jung's experimental research into the association method and the psychogalvanic reflex, his study of mediums and his links with Swiss psychiatry had many unique alliances with the American scene, particularly because of the similar historical relationship between psychology and religion. To understand Jung, therefore, one must consider the archetypal significance of America for Jung's own process of individuation, as well as the subsequent Americanization of Jungian ideas.

The galvanometer is an instrument that measures electrical conductance, while the pneumograph measures respiratory function. The study aimed to assess physiological responses in both normal and mentally ill subjects when exposed to different stimuli and situations. The results of Jung's experiments provided insights into how physiological responses, such as changes in skin conductance (measured by the galvanometer) and respiratory patterns (measured by the pneumograph), may differ between people with and without mental illness. These differences may have helped researchers and clinicians to better understand the psychophysiological aspects of mental disorders and may have contributed to the development of diagnostic and therapeutic approaches in the fields of psychology and psychiatry.

Utilizing instruments such as the galvanometer to measure electrical skin resistance and the pneumograph to track respiratory changes, Jung sought to correlate physiological responses with psychological stimuli, particularly during association experiments. This innovative work highlighted the potential of psychophysiological methods to access unconscious processes, a foundational aspect of Jung’s later theories on the psyche.

Jung's experiments revealed that emotional arousal or the activation of unconscious complexes could elicit measurable changes in physiological parameters, such as variations in skin conductivity or respiratory patterns. By comparing these reactions between healthy participants and those with mental disorders, Jung demonstrated how heightened emotional responses corresponded to unresolved psychological conflicts.