Time behaves strangely inside an operating room. Some mornings it races—induction to incision in what feels like a heartbeat. Other days it stretches so thin that the seconds between a desaturating alarm and the next breath feel like whole lifetimes. After years in neuroanesthesia, I have grown used to this elastic sense of time. But I had never questioned why it felt this way—until a quiet evening when the work by Gunther Kleteschka unexpectedly intruded into my call shift. His paper proposed something audacious: that time may not be a single, one-way river but three separate streams flowing simultaneously. “3 + 3 dimensions,” he called it—three spatial, three temporal. I remember smiling at the idea, imagining my anesthesia workstation needing a new knob for “temporal adjustment.” But as the night progressed and I moved between the operating rooms, checking on anesthetized brains and tenacious ventilators, something about his idea lingered. Because in anesthesia, we too live in more than one time. The EEG screen on the monitor above my workstation flickered in its usual language of oscillations—slow waves blooming like heavy tides, alpha rhythms gathering in frontal leads, spindles sparking like brief shooting stars. These patterns are familiar companions, yet they each unfold on different temporal scales, as if each frequency band keeps its own private clock. Watching them that night, I realized: the human brain is never experiencing just one moment. It is layered in time. And anesthesia, in its quiet, potent way, rearranges these layers. When I administer propofol, I often sense this rearrangement before the patient does. Their breathing deepens, eyelids flutter, and the alpha waves—usually subtle—march forward to the frontal cortex like an organized parade. Slow-delta rhythms swell beneath them, drowning out the fast, nimble oscillations of wakefulness. If consciousness were a conversation across the cortex, anesthesia is not a silencing—it is a sudden shift to a different language spoken in a slower dialect. The physicist’s paper claimed nothing about biology, of course, but his metaphor of multidimensional time felt surprisingly familiar. In the operation room, consciousness doesn’t disappear along a single temporal axis. It dissolves through a collapse of coordination—a loosening of the handshake between brain regions that normally keep each other in sync. As I stood beside an unconscious patient that evening—an elderly man undergoing a craniotomy—I found myself thinking of his brain not as “switched off” but as drifting into a different temporal geometry. His cortex still generated rhythms, but they no longer spoke across distances. The thalamus still pulsed, but its clock no longer set the pace for cortical partners. Long-range networks that once stitched together experience had retreated into their own, isolated forms. We call it “loss of consciousness,” but perhaps it is also a loss of temporal unity. We anesthesiologists track this transformation through indices and numbers—BIS, entropy, spectral edge frequency—each trying to compress the brain’s vast temporal orchestra into a single score. And yet, these devices often miss the moments when consciousness slips unexpectedly between cracks. Despite their sophistication, a minute fraction of patients still recall voices, pressure, or fragments of the surgical world they were meant to be protected from. Maybe the problem is not the monitors. Maybe the problem is that we are asking one number to summarize a brain that lives in many timelines at once. If our machines listened not to a single rhythm but to the interplay between the rhythms … If they tracked not just power, but the choreography of frequencies connecting and collapsing … Perhaps we could understand anesthesia not as a linear descent but as a multidimensional restructuring of time itself. Near the end of my shift, my patient emerged. The alpha rhythms thinned, the slow waves softened, and the monitor’s patterns loosened like a tight knot slowly untying. He blinked at me—just once—and time suddenly felt ordinary again. But I carried the physicist’s idea with me long after the operation room’s light dimmed. I realized that anesthesia is a daily encounter with something profound: the reversible dismantling of the brain’s temporal harmony. We don’t merely guide patients into unconsciousness, we guide them into a different configuration of time. One where the clocks of mind slow, uncouple, and drift away from each other, only to realign when consciousness returns. In the solitude of that evening, amid the hum of anesthesia workstations and the soft rise and fall of the ventilator bellows, I understood that the practice of anesthesia is not just about managing physiology or administering drugs. It is about navigating the layered architectures of time within the human brain. And each time a patient awakens, his eyes open into a single, shared timeline, which we call reality. I feel grateful to have witnessed, if only for a moment, the multidimensional mystery of their inner clocks.
Kunal Kumar Sharma (Wed,) studied this question.