Anesthesia is Like Coma, Not Sleep
Does anesthesia put you to sleep? A long review of what really happens in anesthesia, published recently in the New England Journal of Medicine, points out something cognitive scientists have known for a long time - our layman's terms provide little explanation of how extraordinarily varied human consciousness actually is. Rather than experiencing just different levels of consciousness, we normally undergo many different states.
One is coma - unresponsiveness to outside stimuli, plus a brain that can't accomplish much beyond the amazingly complicated process of keeping you alive. It turns out that anesthesia is a lot closer to coma than some people thought. More bizarrely,sleeping pills like ambien (zolpidem) seem to produce states that ape parts of coma.
So here (with apologies to cognitive scientists and philosophers) is a consumer's guide to the more common states of consciousness you may see in your daily life.
Common States of Consciousness
1. Stage 1 sleep demonstrates that states of consciousness not only fluidly run into each other, but often are not recognized.
Many people have microsleeps of 3-30 seconds at a time, especially when driving late at night. Often they are not experienced as microsleeps, not even as blips of changed consciousness - with sometimes fatal results. Akerstedt's studies of Swedish train conductors showed they routinely fell asleep at night - standing up - with their eyes open. (Fortunately for us, professional truck drivers appear pretty good at knowing when microsleeps are going to hit them.)
A Henry Ford Hospital study by Rosenthal et al. put people into stage 1 sleep for 10 minutes. When it was over, fully half thought they were awake the whole time.
They were not. Some were snoring away..
They just thought they were awake - and argued vigorously with the researchers, even when shown videotapes of what they did those ten minutes.
It may be better to see the brain the way Marvin Mirsky theorized long ago - as a bunch of "kludges", engineering systems jerry built to do one thing like vision, that through evolution got involved in 15 or more activities of which they are necessary but insufficient parts. It's kind of like thinking of a plywood two by four as potentially part of a table, the base of a floor, a weapon, an anti-GERD bed headboard elevator, a plane for writing, a carved signboard, a room divider, a toy, plus who knows what else.
To get to stage 1 sleep you need dozens of different kludges to seamlessly work together. It's more like putting nine separate orchestras in different sections of the Houston Astrodome, some in the boxes, others on the field, a few players in the washrooms, and getting them to simultaneously play the same notes in the same rhythm.
If that doesn't happen you might jerk up like students in high schools and universities do throughout the morning, or like commuters on train cars, or - maybe even you (hopefully not while reading this sentence.)