Biofeedback is the use of a live physiological signal — heart rate, heart-rate variability, breathing — to read the state of the body. In its established sense it means measuring a body signal and reflecting it back so it can be seen and influenced. For us it is first of all a measurement tool, and in time an input.
Calibrating our modules (research). In research and development, biofeedback is how we tune a module to its purpose. We measure what happens in the body — heart-rate variability, breathing, the signs of a nervous system settling — while a module runs, and adjust the light and sound until the response matches what the module is meant to produce. The body’s data calibrates the design.
Measuring whether we met our targets (installations). In an installation, biofeedback is how we check our own claims. If the aim is to bring nervous systems toward coherence and regulation, biofeedback lets us measure whether that actually happened rather than assume it — turning “we think this works” into evidence, and feeding our account of whether an installation met its stated aims. How we define and measure those aims is covered in how we measure success.
Biofeedback as a live input — a future goal. Using a body signal to change the work in real time, with a visitor’s physiology driving the light and sound in a closed loop, is something we intend to build, not something we do yet. The complexity of doing it well is real, and we would rather name it as a direction than overstate it as a current feature.
Where the evidence lives. The research base biofeedback draws on — the literature on heart-rate-variability biofeedback and paced breathing — sits with our research arm, not in this vault.