Signals, not screens: a way to think about XR
If we treat extended reality as a screen strapped to the face, we miss the point. The interesting surface is the human in the loop.
It’s tempting to evaluate a headset the way we evaluate a monitor: resolution, field of view, refresh rate. Those matter. But they describe the display, not the experience — and the experience happens in a body.
The human is the other half of the system
Every immersive moment is a loop: the system renders, the person perceives, their body responds, and that response should — ideally — feed back into what the system renders next. When we ignore the return path, we get experiences that look stunning in a spec sheet and make people queasy in practice.
Physiological computing is just taking that return path seriously. Cybersickness, presence, fatigue, delight — these leave traces in heart rate, in the eyes, in the skin. Read them, and the system can adapt.
Why this is hard
Signals are noisy, individual, and context-dependent. A spike in heart rate might be excitement or nausea; the same content affects two people differently. That’s exactly why it’s a research problem and not a checkbox — and why the work is far from done.