This article investigates the relation between signifying processes and non-signifying material dynamism in the installation Pulse Room (2006) by Mexican Canadian artist Rafael Lozano-Hemmer. In Pulse Room the sense of pulse is ambiguous. Biorhythms are transmitted from the pulsing energy of the visitor's beating heart to the flashing of a fragile light bulb, thereby transforming each light bulb into a register of individual life. But at the same time the flashing light bulbs together produce a chaotically flickering light environment composed by various layers of repetitive rhythms, a vibrant and pulsating “room”. Hence, the visitor in Pulse Room is invited into a complex scenario that continuously oscillates between various aspects of signification (the light bulbs representing individual lives; the pulse itself as the symbolic “rhythm of life”) and instants of pure material processuality (flickering light bulbs; polyrhythmic layers). Taking our point of departure in a discussion of Gilles Deleuze's concepts of modulation and signaletic material in relation to electronic media, we examine how the complex orchestration of pulsation between signification and material modulation produces a multilayered sense of time and space that is central to the sensory experience of Pulse Room as a whole. Pulse Room is, at the very same time, a relational subject–object intimacy and an all-encompassing immersive environment modulating continuously in real space-time.Merete Carlson is Ph.D. Fellow at the Department of Scandinavian Studies and Linguistics, University of Copenhagen. Her current research focuses on corporeal issues of sensory and affective engagement in contemporary media art. Carlson's Ph.D. thesis is entitled Towards a Responsive Aesthetics: Sensation, Self-Movement, Affect [in Danish].Ulrik Schmidt is postdoctoral fellow, Ph.D., at the Department of Arts and Cultural Studies, University of Copenhagen. His main research is in cross-aesthetic issues within modern and contemporary art, film, sound and media culture. Schmidt has published in Danish and English on various topics including music, sound and design in Phil Spector, mass comedy in Buster Keaton, ubiquitous computing, digital art, and minimalism in art and music. His dissertation investigates ambient aesthetics in modern art, film, music, and architecture (The Ambient, Aarhus University Press, 2012 (forthcoming) [in Danish]).