I’m Awake! The battle in your brain to avoid nodding off
For those of use prone to burn the candle at both ends, there’s a moment that is all to familiar when you unintentionally fall asleep before snapping awake again, sometimes repeatedly. If you’ve had to stay up after pulling an all-nighter, or say, are a parent of a small child, you’ve probably experienced this “micro-sleep” moments, where you intend to stay awake but your eyes seem to have their own agenda, fighting you for control of your consciousness.
It turns out, it’s actually a much more involved neurological tug-of-war than was previously understood. Test subjects were kept awake for 22 hours, then told to keep their eyes open in a dark fMRI for 6 minutes. As their eyes dropped shut, a spasm of activity was seen in their brain. Activity in the thalamus decreased, indicating a shift away from external stimulus. Conversely, other parts of the brain snapped into action, ranging from emotional and memory centers to the “error monitoring” cingulate cortex. Even areas associated with attention and concentration activated, indicating that at least part of the brain really was trying hard to keep things going.
Mish-mashed dreams from micro-sleep
The experience of all this can be quite jarring. Aside from the moment of reorienting oneself once your eyes open again, micro-sleepers often experience what’s known as hypnagogic states. In this context, the hypnagogic states are like brief, confused edits of normal dreams. You might occasionally recover with the more complex narratives of a dream from REM sleep, but micro-sleepers usually just report a flurry of imagery, possibly from the spike in activity as their brain tries to stay awake. From my own experience, I know I’ve caught myself making bizarre rewrites of my kids’ Thomas the Tank Engine books when sleepily reading to them at 6:15 am. Fortunately, my two-year-old hasn’t complained beyond the occasional quizzical look when Percy suddenly enters into an argument with my third grade teacher about car repair, as long as I snap out of my haze in a timely manner.
At this point, there’s not much more you can do with the moments of neurological conflict other than realize that your brain is working hard to help you through a situation that you would be better off avoiding in the first place. A lack of sleep is stressful at best, and possibly even dangerous. So on that note, I need to get to bed. My son will be up before I know it.
Source: What’s Happening in Your Brain When You Can’t Stay Awake by Christian Jarrett, Science of Us