Leoš Janáček's fascination with the trappings of experimental psychology has boosted his image as a kind of realist, for whom empirical engagement with psychological experience was a prerequisite for aesthetic value. Yet careful contextualization of the sources he drew upon in later years suggests that such discourses—above all, the work of Wilhelm Wundt—work ironically against the constitution of the expressive subjectivity we are used to inferring in his work. An emblematic case in point is Janáček's use of an experimental research instrument known as the “chronoscope,” which psychologists had traditionally used for studying reaction times, a formative concern for the discipline since its emergence in the 1870s. While remarkable for its utility in accurately measuring extremely short durations, the chronoscope also highlighted the temporal limits of perception. It appealed to the composer's obsession with minute details of sensation, but it can also be seen to raise questions about the integrity or continuity of the very image of subjectivity it was meant to ascertain. The conjunction of the chronoscope's dramatization of short timespans and Janáček's related concern for the calibrated gesture together suggest a mode of interpretation through which the expressive impulse in his music may be sensed as incipient, in a state of deferral, rather than as the immediate manifestation of an integral lyrical self.