My dissertation focuses on the notion of “gesture” as a somatic manifestation of psychological experience. This view of movement was elaborated by late 19th-century psychologists, who gave up the metaphysical notion of the soul in favor of neuro-physiological approaches to behavior. My study shows how the new scientific discourse penetrated into a broader cultural sphere, generating wide interest in the question how the body participates in and reflects affective and cognitive processes. I examine the modes of recording, representing and interpreting body movement as “expressive.” Based on archival materials and periodicals, I chart out avenues by which the ideas and methods of physiological psychology reached artists and writers – a task, which involves evaluating institutional practices and cultural-political trends that promoted interdisciplinary engagements. Ultimately, my study demonstrates how scientific discourse transformed techniques of film acting, prompted film industries’ inquiries into spectators’ physical reactions, and spurred literary scholars’ investigations of poets’ intonation and body movement. Yet, rather than positing the direct influence of science, I attend to a variety of ways in which writers and artists reinterpreted, defamiliarized and resisted the positivist outlook brought forward by physiological psychology. In Chapter 1, I show how Viktor Shklovskii drew on William James’s theory of the corporeal experience of emotion and Wilhelm Wundt’s ideas on the gestural origin of language to discuss Russian Futurist poetry as a “ballet for the organs of speech.” Chapter 2 analyzes Boris Eikhenbaum’s essays on poetic declamation by placing them in the context of the Petrograd Institute of the Living Word. In this organization, Russian Formalists worked alongside speech therapists and psychologists, using parlograph records of poetry performances. I compare their methods of registering poetic intonations to similar endeavors by American phoneticians Edward Scripture and R.H. Stetson. Chapter 3 traces the origins of Lev Kuleshov’s system of film actors’ training, arguing that his ideas emerged at the juncture of avant-garde theater, Pavlovian reflexology, and labor efficiency movement. Chapter 4 considers psycho-physiological approaches to film spectatorship, focusing on American and Soviet efforts to assess the emotional responses of filmgoers by photographing their facial reactions and registering changes in their vital signs.