  We put forth Physiologically Driven Storytelling, a new approach to
interactive storytelling where narratives adaptively unfold based on the
reader's physiological state. We first describe a taxonomy framing how
physiological signals can be used to drive interactive systems both as input
and output. We then propose applications to interactive storytelling and
describe the implementation of a software tool to create Physiological
Interactive Fiction (PIF). The results of an online study (N=140) provided
guidelines towards augmenting the reading experience. PIF was then evaluated in
a lab study (N=14) to determine how physiological signals can be used to infer
a reader's state. Our results show that breathing, electrodermal activity, and
eye tracking can help differentiate positive from negative tones, and
monotonous from exciting events. This work demonstrates how PIF can support
storytelling in creating engaging content and experience tailored to the
reader. Moreover, it opens the space to future physiologically driven systems
within broader application areas.
