Digitally presenting physiological signals as biofeedback to users raises awareness of both body and mind. This paper describes the effectiveness of conveying a physiological signal often overlooked for communication: breathing. We present the design and development of digital breathing patterns and their evaluation along three output modalities: visual, audio, and haptic. We also present Breeze, a wearable pendant placed around the neck that measures breathing and sends biofeedback in real-time. We evaluated how the breathing patterns were interpreted in a fixed environment and gathered qualitative data on the wearable device's design. We found that participants intentionally modified their own breathing to match the biofeedback, as a technique for understanding the underlying emotion. Our results describe how the features of the breathing patterns and the feedback modalities influenced participants' perception. We include guidelines and suggested use cases, such as Breeze being used by loved ones to increase connectedness and empathy.Signals such as heart rate and electrodermal activity (EDA), which measures perspiration, can also serve as proxies for social interactions [37]. Breathing presents an advantage over such signals because it can easily be modulated. In the field of human-computer interaction (HCI), breathing and other physiological signals have been used mainly as input [35,39]. Instead, we employ these technologies to support humanhuman communication as advocated by [13].We envision a future where interfaces can "connect" people at a distance, enforcing a bond between close ones through shared wearable biofeedback. While trying to develop such an arXiv:1802.04995v1 [cs.HC]

Figure 1: A story is rendered with PIF while physiological signals are monitored and analyzed in the background to comprehend the reader's experience. The detection of specific states can be used to automatically change the story and augment reading experience as the interactive story unfolds.