Yesterday, I had a coronectomy: the top halves of my bottom wisdom teeth were surgically removed. It was my first time being sedated, and I didn’t know what to expect. While I was unconscious during the surgery, the hour after surgery turned out to be a fascinating experience, because I was completely lucid but had almost zero short-term memory.

My girlfriend, who had kindly agreed to accompany me to the surgery, was with me during that hour. And so — apparently against the advice of the nurses — I spent that whole hour talking to her and asking her questions.

The biggest reason I find my experience fascinating is that it has mostly answered a question that I’ve had about myself for quite a long time: how deterministic am I?

In computer science, we say that an algorithm is deterministic if it’s not random: if it always behaves the same way when it’s in the same state. In this case, my “state” was my environment (lying drugged on a bed with my IV in and my girlfriend sitting next to me) plus the contents of my memory. Normally, I don’t ask the same question over and over again because the contents of my memory change when I ask the question the first time: after I get an answer, the answer is in my memory, so I don’t need to ask the question again. But for that hour, the information I processed came in one ear and out the other in a matter of minutes. And so it was a natural test of whether my memory is the only thing keeping me from saying the same things on loop forever, or whether I’m more random/spontaneous than that.^[1]

And as it turns out, I’m pretty deterministic! According to my girlfriend, I spent a lot of that hour cycling between the same few questions on loop: “How did the surgery go?” (it went well), “Did they just do a coronectomy or did they take out my whole teeth?” (just a coronectomy), “Is my IV still in?” (yes), “how long was the surgery?” (an hour and a half), “what time is it?”, and “how long have you been here?”. (The length of that cycle is also interesting, because it gives an estimate of how long I was able to retain memories for — apparently about two minutes.)

(Toward the end of that hour, I remember asking, “I know I’ve already asked this twice, but did they just do a coronectomy?” (The answer: “actually you’ve asked that much more than twice, and yes, it was just a coronectomy."))

Those weren’t my only questions, though. About five minutes into that hour, I apparently asked my girlfriend for two 2-digit numbers to multiply, to check how cognitively impaired I was. She gave me 27*69, and said that I had no trouble doing the multiplication in the obvious way (27*7*10 – 27), except that I kept having to ask her to remind me what the numbers were.

Interestingly, I asked her for two 2-digit numbers again toward the end of that hour, having no memory that I had already done this. She told me that she had already given me two numbers, and asked whether I wanted the same numbers again. I said yes (so I could compare my performance). The second time, I was able to do the multiplication pretty quickly without needing to ask for the numbers to be repeated.

Also, about 20 minutes into the hour, I asked my girlfriend to give me the letters to that day’s New York Times Spelling Bee, which is a puzzle where you’re given seven letters and try to form words using the letters. (The letters were W, A, M, O, R, T, and Y.) I found the pangram — the word that uses every letter at least once^[2] — in about 30 seconds, which is about average for me, except that yesterday I was holding the letters in my head instead of looking at them on a screen. I also got most of the way to the “genius” rank — a little better than I normally do — and my girlfriend got us the rest of the way there.

A couple hours later, when I was home, I could remember two of the Spelling Bee letters — W and O.^[3] I asked my girlfriend to give me the letters again, and this time it took me longer to get the pangram: about two minutes.

Overall, this suggests that I was not cognitively impaired at all during that hour (except of course for the my memory). I find this really interesting, because I would have expected that whatever mechanism knocked me out and severely impaired my memory would also give me like a 50-point IQ drop. But apparently not!

The surgery went pretty well, but there was a strangely-textured fluid by my bottom-right wisdom tooth. If it turns out to be a scary sort of fluid^[4] (I’ll find out on Tuesday), then I may need a second operation. On the one hand, that would suck. But on the other hand, now that I have a better sense of my post-operative condition, I can plan some more experiments!

My friend Drake suggested an experiment that I’d be really excited to try: my girlfriend (or whoever’s with me) could repeatedly ask me to generate a random number between 1 and 100. Yesterday showed that I’m pretty deterministic; but am I so deterministic that I would say the same number every time I was asked? My guess is no, but also that I wouldn’t be great at generating random numbers. It turns out that if you ask ChatGPT for a number between 1 and 100, it’ll say 42 10% of the time, 47 and 57 about 7% of the time, and some numbers (like 30, or anything below 15) pretty much never. Would I be better or worse than ChatGPT at producing uniformly random numbers? Who knows!

I could also be repeatedly asked a question that I don’t have a cached answer to (like “What’s your favorite geological formation?”) and see if I produce the same answer every time.

More ambitiously, I could be given a streaming problem to solve. Streaming algorithms are algorithms for computers that have extremely limited memory. For example, in the count-distinct problem, you’re given a long list of numbers and are asked to count the number of distinct entries in the list. If you can remember every number that has appeared so far in the list, then this problem is easy. If you can’t remember the numbers, then you can’t reliably count the exact number of distinct entries, but there are clever schemes for getting close to the right answer! I think this is cool because it lets you overcome a deficiency (lack of memory) with cleverness. I don’t know how fun it would be to try this particular problem, but there’s probably some streaming algorithm that would be fun to implement!

Drake (who suggested the random number experiment) also told me about a truly wild experiment that he conducted while getting his wisdom teeth removed:

Several years ago, I was thinking about worthwhile precautions to take against strange scenarios and wanted a way to defend against erasure of my short-term memory, e.g. by the CIA or alien abductions. I’d heard the factoid that every time you think through a memory you end up overwriting it, which suggested a loophole: build up a long-term memory ahead of time, with a designated piece of the memory to fill in as necessary. Then, when you want to send a message through the barrier of your future amnesia, you think through the old memory with your target message inserted, thereby writing directly into your brain’s long-term storage and bypassing the cache that would otherwise get erased. I kept up a habit of occasionally thinking through a false ‘memory’ of coming downstairs on Christmas morning and opening up a large present, but ending the scene before I saw what was in the box.

I had the opportunity to try this out while getting my wisdom teeth removed, when I was put under the influence of a relaxation and memory-inhibiting drug. When I left the operating room, I consulted my memory and found that the box contained a Martian landscape with a drill boring into the bottom right corner. Judging by the other bits of context that felt associated with the scene, I think my drug-addled brain was trying to use the Martian landscape as a metaphor for lacking proprioception in my mouth and being uncertain of its internal topology, while the drill was a metaphor for a drill. I don’t remember anything else between 30 seconds after they put the IV in to when I walked out of the operating room.

But Drake notes:

While I’m confident that the memory really was a result of thoughts I had under the influence of amnesiac drugs, I’m only around 50% sure that this strategy worked via the intended mechanism, and it’s plausible that I just thought about this scene hard enough during the surgery to overcome the effects of the drug (and anyone focusing on a particular image for a couple minutes with the intent of remembering it in that scenario would have succeeded).

To test whether Drake’s circumvention of his short-term memory loss worked via the intended mechanism, I could ask my girlfriend in advance to prompt me once — and only once — to complete the long-term memory scene that I had been practicing. Then I could see if I have a memory of the scene after I fully regain my memory.

I would love to hear suggestions for other things I could try. If you have any, let me know in a comment!

1. ^{^}

   Of course, my actions are fully determined by my entire brain state. But it seems plausible that low-level effects that change unpredictably (like which particular neurons happen to be firing) would affect my words and actions, and also plausible that these low-level changes wouldn’t affect my words and actions.

2. ^{^}

   The pangram was MOTORWAY. (This was in fact the only pangram.)

3. ^{^}

   My theory is that we had been playing Spelling Bee for enough time that the letters somewhat made it into my long-term memory.

4. ^{^}

   The surgeon said he was “100% sure” it wasn’t cancer. But it could be a benign tumor that would need to be dealt with anyway.