The first time I fainted, I was seven. I passed out while racing my fellow second-graders across the playground. One minute, I was leading the pack in the race; the next thing I knew, I was lying in the nurse’s office with adult faces hovering all around me. My parents explained to me that I’d lost consciousness - it was like falling asleep for a minute, they told me.
It frustrated me to no end- even as a seven year old - that I didn’t know where that time had gone. Why couldn’t I remember those moments where I collapsed onto the grass and got scooped up by a petrified teacher? I ended up fainting a handful of times over the next few years (luckily doctors chalked it up to nothing more than dehydration and a genetic propensity to faint), and each time I was reminded of that frustration of not being able to grasp what was going on in my brain during those lost minutes.
As a seven-year-old, I didn’t have the chance to call up scientists and ask them to explain the brain to me, so when I started working on a feature article on consciousness for the latest issue of Stanford Medicine magazine, I was thrilled that maybe I’d get that chance to finally answer those questions that had been lingering in my head for decades. What makes the brain go from awake and aware to such a blank state, and then back again?
But it’s not that simple, I learned: There’s no single switch that flips the brain from conscious to unconscious. In fact, consciousness isn’t an on-off switch at all; it’s a whole spectrum of states. Anesthesiologist Bruce MacIver, PhD, pointed me toward this handy chart that shows different levels of consciousness. Each state of consciousness has its own unique place on two scales: physical arousal and mental awareness. As I looked at it, I realized that my experience with altered consciousness wasn’t just limited to my childhood fainting episodes - we all go in and out of multiple states of consciousness on a daily basis, and not only when we fall asleep and wake up.
“If you’re an elite athlete and you get in that so-called ‘zone,’ that’s an altered state of consciousness,” anesthesiologist Divya Chander, MD, PhD, explained to me. I’m no elite athlete, but after talking to Chander, I suddenly started paying attention to those not infrequent times when I “zone out” while driving or exercising. And when I woke up to a noise in my house on a recent night, I immediately noticed my heightened senses - that alertness is an altered state of consciousness too.
“What I’m always hoping is that hearing about this kind of work makes people ask more questions about what it means when they themselves enter different states,” Chander said to me when we talked. Her message was not lost on me; I’ve become an active observer of my shifts in attention and awareness.
My Stanford Medicine story delves much deeper than these observations of daily life, to look at how and why anesthesiologists are probing what it means to be conscious - and how their research could lead to better anesthetic drugs. But I hope that in addition to conveying the science, it also helps readers realize that subtle changes in consciousness happen in your brain all the time.
As for the questions I had as a seven-year-old, they’re not fully answered, but I’ve only gotten more intrigued to know how the brain mediates consciousness, and more excited to follow where this research goes in the future.
Sarah C.P. Williams is an award-winning science writer based in Hawaii, covering biology, chemistry, translational research, medicine, ecology, technology and anything else that catches her eye.
Previously: Stanford Medicine magazine opens up the world of surgery, Your secret mind: A Stanford psychiatrist discusses tapping the motivational unconscious and Researchers gain new insights into state of anesthesia
lllustration by Jon Han