For some years now, in Quebec as in Europe, many artists have been staging theatrical trajectories where the spectator circulates in a more or less structured fashion. Whereas some of these artists privilege some restriction of physical mobility and propose a carefully mapped out course, others prefer to let the spectator rove at will in a place of shifting, undefined boundaries. This physical engagement by the spectator, in a space that he or she moves through and shares with actors (present or virtual,) leads to particular modalities of reception. The present article discusses the relationship to space, sound environment and actors (projected and present) based on examples from the productions Resonances by Carole Nadeau and Himmelweg by Geneviere L. Blais to examine the ambiguous relationship to performance developed by spectators who are cast into a stage setting where they perceive their own activity, becoming ever more acutely self-conscious. The author focuses in particular on the "white" or interstitial moments that punctuate the spectator's movement. Moments of pure self-presence, occurring whenever images disappear or voices fade, abolish the relationship to the Other and suspend attention to the performance.