We think that neural activity creates subjective experience (“phenomenal consciousness”) but lack a satisfying, quantitative understanding of how that actually happens. Near the heart of this mystery is the binding problem, which I understand as having two main sub-questions: The human brain is composed of billions of neurons over more than a thousand cubic centimeters, and neural activity relating to consciousness unfolds in time over tens of milliseconds, which we nevertheless experience as an integrated phenomenal “moment.” How does this spatiotemporally extended neural activity get “bound” together into a unified experience? Our moments are structured into modes — vision, audition, somatosensation, proprioception, etc — that appear to be somewhat independent though which we experience jointly, and we always experience all of our own modes together and never, say, my vision and your hearing. How does this happen? Put differently, how is the “border drawn” around a brain?