Is this a similar effect to people developing tolerance to low oxygen/low air pressure conditions? Or maybe actually exactly the same effect (i.e., increased red blood cells in people who are in low oxygen environments for long periods of time?)
Is the CO2 in my room really high (possible, even with windows wide open; thanks, wildfires!), or does that word not actually exist in the grid? There is no neighboring "C" and "H" pair on this board.
Extremely cool. One possible way to salvage the original result is if there is a cumulative threshold effect: maybe you need to be in a low-carbon environment for a long time to see effects and if you regularly breathe fresh air your mental function is not affected. This wouldn't explain the submarine data point though
Unfortunately, some of the pro-CO2 papers claim acute effects. Like Satish's experiment used 1 hour of exposure pre-testing (https://ehp.niehs.nih.gov/doi/10.1289/ehp.1104789), and is one of the most-cited ones and has p-values out the wazoo.
I'm not sure it would be that obvious. Recent analysis of court records have shown that judges levelled more severe sentences against guilty offenders the lower their blood sugar, ie. that hungrier they got/closer to lunch, they became hangry. After their lunch their sentencing severity popped back up nearly where they were at the start of the day.
I suppose we'd have to survey lawyers if this was common knowledge, but my understanding is that it wasn't.
It's an interesting example of a claim that spread through headline repetition, when anything other than headline repetition would have instantly discredited it. The effect size found in the study was a *one hundred percent reduction* in the likelihood of being acquitted as you get closer to lunch.
Without any knowledge of lawyers, I'd say they were aware that the guy scheduled immediately before lunch isn't going to be acquitted, and isn't going to take very long - but that they would have provided the same explanation as all subsequent discussion of the paper has, that the court schedule is not determined at random, and that guy was placed before lunch because he was going to be convicted in a short, predictable amount of time.
I found something else more recent which found the effect size to be overestimated* though because of the varying length of cases, instead of time of scheduling, so it may still be debunked. That's as far as I'm reading for now, but there's a lot to it. Thanks for sharing that, I hadn't thought to question it before.
Also, it's a long way from "affects our mood" to "affects our mood in this particular way, under this particular circumstance, all other things being equal, x% of the time."
I recently (June) started monitoring AQ in my condo after reading similar studies, watching a presentation by DHH from Basecamp (MRqh8oLY7Ik) and trying to find ways to help my wife's migraines. I'm using the Awair AQM8002A.
Our overnight CO2 in our bedroom (shared with 3 children) went up as high as 1300ppm and rarely went under 900ppm any time during the day. I tried opening windows and I could push it down to 700 but as soon as I closed the window (since it's July in Houston) it shot right back up. The humidity however took much longer to recover.
We left for a month and it went down to the 400s (set the temperature to 78 instead of 71).
I just used Condensate Pan Treatment Tablets (Uric acid) two days ago and our overnight reading have gone down to high 700s (from 1300ppm). I've had a lot of trouble figuring out how such a large change in CO2 could have been caused by micro-organisms in the condensate pan... My first thought is faulty meter, which I haven't tested.
No way to know the effect on migraines as it's a long term occasional problem. My personal waking fatigue is much improved though.
Is urban dictionary a valid source of words for the game? Narc…
Could there be factors other than CO2 that correspond to ventilation? Air flow, humidity, level of VOC, sound levels, etc.
I sleep much better with a fan. A study might show that people sleep better with fans running. Headline, “Studies show high air flow helps sleep.” Later we find out it’s the white noise that’s helping.
You should go decide which environmental factors to record for each game in advance so that you don't need to play 800 new games every time someone brings up a random factor that is potentially correlated to intelligence.
Some factors that might be worth recording, in addition to co2 and humidity, in no particular order:
- How much you slept
- VOCs
- Ambient sound level
- Air flow
- Stress (as in how much other stuff you have to do soon)
- Sugar intake
- Lighting
- Screen time
- Commute length
- Obesity?
- Chewing gum
- Watching stupid entertainment shows
- Fluoride
- Meetings
- Secondhand smoke
- Whether you took Ambien/Xanax/etc
Also, random thought: If you don't want to play the word game yourself a bunch of times in order to test hypotheses about human cognition, you might want to ask (some of) us, the vast ACX readership, to do it on your behalf.
Recording for each individual game, how many games immediately prior in a session and how you scored, might not be a bad idea. I get into a zone with my certain computer game and my performance usually improves for a few games in a row, then drops and improves again. If you were playing one game a session you’d always be cold, but if you play in blocks this tendency to temporarily improve might obscure whatever the CO2 was doing to your scores in general. Given a repeated task in the presence of some high but more or less constant level, maybe the brain adapts to the situation at the time.
If you are modifying the experimental conditions anyway, and there are no budgetary constraints, I'd suggest following additions:
(1) Air oxygen meter.
(2) Get an app that beeps at regular times (or random times could work too) and asks you to record if you feel like playing or not and record the air metrics. Get automated sensor that record the metrics anyway, so it is less work. Maybe you know someone who can hook the sensors into an Arduino board / RasPi?
The previous data from the same location can also be quite useful.
> I don't think it's likely that it causes the Dutch East India Company.
I also agree with you that humidity is not the ultimate cause of the existence of the Dutch East India Company, but I also think that the phrase "Dutch East India Company" in the above comment is a malapropism.
I think they're making fun of you and BronxZooCobra for using the acronym "VOCs" without ever explaining what it means, since VOC was also the acronym for the Dutch East India Company.
Google suggests "Volatile Organic Compounds". I assume it's something along the lines of pollen count.
You might find this amusing, if you haven't heard of it before: There's an urban legend that sleeping with a fan can kill you. https://en.wikipedia.org/wiki/Fan_death
(I also sleep with a fan. It hardly ever kills me.)
Some spaniard scientist seemed pretty alarmed by the effects of infrasound on airplane crews´ blood vessels at one fascia congress and advised to shun computer fans. But that was at a conference years ago and today I guess there's not much behind it.
My anecdotal evidence is that I feel better and more alert when I ventilate the car on long drives. But in car CO2 levels be much higher than a house or apartment. I can’t think of a good way to test this.
I had wanted to measure this exact same thing - ever since I moved into my current flat I feel that I can work so much better with the windows open. And the price did stop me - I thought these monitors were around $10 when I got the idea (why do they cost so much?). So... if logistics of me being in the UK is not an issue, I'd be happy to test?
Send me an email at scott@slatestarcodex.com with your planned experimental protocol (doesn't have to be too official) and your address and we can talk about it.
If you're actually willing to buy the monitor for someone(s), I suspect you'll find plenty of video game streamers who would be willing to do this as a gimmick on their stream for some weeks, so then you'd just have to decide which game(s) you think are more "cognitition" focuses.
I'm a streamer. https://www.twitch.tv/nebupookins I'm open to playing a wide variety of games on stream (except I don't like to play horror games). I've also bought two CO2 monitors after reading this post (not the one you recommended, a $30 one and a $50 one) with the expectation that if they both report the same reading, they're probably both accurate, but if they report different things, then one (or both) of them are inaccurate.
I'm really curious if you have some suggestions for experimental protocol.
Are you playing any competitive online games? Overwatch, League of Legends, Starcraft? Those usually have pretty detailed statistics for player performance. I play LoL and third party apps like Porofessor show me very detailed stats per match, from "teamfight participation %" to "creeps farmed per minute". But to avoid multiple comparison adjustments, I'd just stick with measuring competitive score progression. If you gain more points when playing in the fresh room than in the stuffy room, this is good evidence for the effect.
I'm streaming too sometimes, a mix of Russian and English streams, gaming and photo editing. https://www.twitch.tv/loweren
I used to play League, but my performance in League already has insanely large variance so not sure it'd be a great metric for me. E.g. creeps per minute varied by a factor of 18.5.
A lot of recent top-level chess has been sponsored by an air quality monitoring company who used this gimmick. Eg you can see it at 1h30m here: https://youtu.be/EmVuLy08Y4k. The commentators sometimes mention it too, in order to help the sponsor.
If any streamers are reading this: I would find this gimmick pretty entertaining, and would direct some money/views toward a streamer who did this in an at-least-moderately-careful way.
How would you make it fun without unblinding the gamer about CO2 levels? Or maybe blinding is asking too much since people can usually sense low oxygen anyway.
People can't sense low O2 - that's why simple asphyxiants like nitrogen and the noble gases can kill. What we sense is high CO2 directly.
(Simple asphyxiants are dangerous because breathing them doesn't give O2 but does remove CO2 - as such, you don't sense "bad air", you just pass out from lack of oxygen and then die.)
Confused though, nitrogen and noble gases aren't converted to CO2 by the body right? Is this part of why CO is so bad? CO would be converted to CO2. Though CO binds to hemoglobin so strongly this effect is probably negligible for CO.
What's the mechanism for this exactly? How do we sense the high CO2 that makes us want to breathe out? CO2 is pretty inert. Is it through CO2 acidifying water? If I put another gas that acidifies water in the air does your body start to process it as CO2, and will you have trouble even if there is enough O2 in the air?
Lots of questions, but would like more explanation here!
I'm speaking about the case where you're breathing pure N2 (or another gas/mixture that while not toxic does not contain O2).
If you're breathing pure N2, you will indeed maintain low levels of CO2 and not be poisoned by it. However, you need a constant supply of O2 in order to live, and pure N2 by definition doesn't have any. As such, after a couple of minutes of breathing pure N2 you will pass out from lack of oxygen (and then die unless rescued).
This form of asphyxiation (no CO2 accumulation, just lack of O2) can only occur if you are breathing gas with low CO2 and also low O2 - this is highly unusual, because "bad air" breathed out by other animals will reach dangerous levels of CO2 long before the amount of O2 drops to insufficiency (40,000 ppm of CO2 is 100x current baseline/150x pre-industrial and immediately dangerous to human health, but that's only 4%; animals use something like 1-1.5x as much O2 as they produce CO2, but even a 6% drop in O2 from the 20% baseline is still 14% - more than half of it is still there). The usual cases for sudden anoxia are sudden decompression of a plane, huffing helium balloons, SCUBA accidents or improper storage of cryogenically-liquified gases - to put it mildly, not the conditions natural selection designed us for.
I'm not 100% sure of the way by which we sense high CO2. I do know that strongly-acidic gases like HCl, NO2 or SO3 are very dangerous to breathe, although this has more to do with direct acid damage to the lungs than with homeostatic errors.
Cool! What's the mechanism by which CO2 is dangerous? If I breathe in something is just like air except with the CO2 in place of the nitrogen, so the oxygen content is still good, what happens exactly? Acidification, some of reaction A + B <-> CO2 + X where the equilibrium is off, something else? Why would I die? Isn't CO2 a relatively inert gas?
It is one of the cases where evolution cuts corners that no good engineer would: it tests something easy (CO₂ → acidity was my guess too) that is strongly correlated *in nature* with the thing it needs to test (O₂).
I learned recently (although I would need confirmation) another example: water. We feel thirsty when we need water, and we get minerals at the same time. We do not have a feeling for the lack of these minerals. Therefore, drinking distilled water will sate our feeling of thirst, but will not supply our body all it needs.
CO is bad because it binds to the heme group in hemeglobin better than O2, so it will displace O2. That is, your red blood cells will absorb CO before they absorb O2. It also induces a conformational change in hemoglobin that inhibits oxygen unloading, so even the O2 that is left isn't delivered efficiently to tissues. CO2 doesn't bind to hemoglobin at all, it's quite a different looking molecule.
Yes, the main sensors controlling breathing in the brainstem sense H+, which increases with CO2 levels because dissolved CO2 largely forms carbonic acid by interaction with water. There are additional sensors that directly detect O2 levels also.
Acidifying blood per se is not thought to trigger increased breathing, because the detectors are actually sensitive to H+ in the cerebrospinal fluid, so something has to cross the blood-brain barrier (which H+ cannot) and *then* cause a decrease in pH. CO2 does that.
Very cool. So, is there any other gas that makes a weak acid and achieves the same effect? I'm thinking about SO2 (which is nontoxic right) for instance. SO2 also gives you the acidification thing? You don't have the A+B <-> X + SO2 thing though.
Haemoglobin does bind CO2, via the N-terminal amino group (which can be carbaminated). It's a minority of the blood's transport capability, and it certainly doesn't involve the haem site, but it's not correct to say Hb doesn't bind CO2.
Don't need to worry about which are more "cognition" focused. Cover a wide array of genres and stream types and see if any have a marked effect. If the effect is indeed specific to a certain kind of decision making, this could tease out what it is.
Personally, I feel like there *might* be an effect for tasks that depend heavily on what people call "emotional intelligence" (scare quotes), but not for anything else (unless you want to talk about long-term carbon dioxide overexposure or something, which is a different topic).
Yeah I'm wondering about coming up with new ideas vs repetitive things. Again this is because a lot of people come up with new ideas while outside walking, and my suspicion is that the mechanism for this is probably not CO2 but it's a reason the CO2 hypothesis sounded plausible to me. I also feel I can focus better when the window is open, but it could just be a placebo effect or it could be that the sound from outside is some sort of white noise, or that having some change in the background stimulates new ideas (maybe it's extra hard to work and come up with new ideas while staring at a white wall) or something else I don't know.
I think there is a lot of interesting stuff in this space that is chronically under-explored, and which needs more empirical data so we can all figure out how to work more efficiently. This seems like a pretty underfunded direction of research...
It would also be interesting to see if there is a "natural" way to split various human activities, and whether differential effects on how well we can do them from various outside influences can be used to classify them. So is there some way in which tasks A,B are more alike to each other than C,D, in that A,B both become harder under circumstance X but not C,D? It would also be interesting to look at the corresponding brain activity while doing all of these but this would be hard unless you had some kind of mobile pocket MRI machine.
Again I think there are a lot of interesting questions here. We should try to understand them better because the upside could be potentially ginormous.
Nice self-replication! And I'm pretty convinced by your successive ruling-out of explanations as to why the effect is real but you failed to detect it (e.g., controlling for temperature).
Sorry if you mentioned this and I missed it, but is there any chance that time (like "index" of the trial/game) was a factor? Like, maybe you got better at the game over each successive play, but CO2 levels were also positively correlated with time? In which case you might mask a "real" effect of CO2 if performance is driven by Time (+) and CO2 (–). As you say, to salvage the effect you'd need for these effects to be of roughly the same size, which is a stretch. But might be worth checking.
Another possibility would be that you're already so good at the game that you're essentially at ceiling, so there's just not enough variation in your performance to explain, even though you observe plenty of variation in CO2 levels.
I don't love this explanation because to take it seriously, you'd need an account where the influence of CO2 is dependent on prior ability in the task. Basically an interaction between Expertise and CO2 on Performance, such that High Expertise is somehow "immune" and Low Expertise is more susceptible to CO2 levels. I guess this is in principle possible, especially if the task is easy enough for people with high verbal reasoning/fluency. But: 1) it doesn't seem that intuitive to me; 2) if it is true it's a pretty big caveat for the initial results, and implies they must've sampled from Low Expertise population to have detected an effect (assuming they didn't regress out Expertise); and 3) now we're just adding epicycles.
If you mean getting better over successive games over the course of months, this is definitely happening, but CO2 isn't changing consistently (other than I guess in the global warming way, which is much slower). If you mean getting better over successive games in the course of a sitting, I have the data that would let me test for that but I haven't done it - just eyeballing it it doesn't look that way, nor does CO2 go up very much over the course of my sittings (I usually play only 3 or 4 games max in a sitting, which takes about 15 minutes, which isn't enough time for room CO2 to increase much)
I'm definitely not at the ceiling - my "score" (which I calculate artificially as score divided by average score for the board) has varied between 54% (my worst game) and 143% (my best) over the past month. The world record for most boards is often around 2x my own score.
Yeah I meant the former ("getting better over the course of months")––I just thought maybe if time was correlated with wildfire season or something, you might detect higher CO2 levels. But that makes sense! Seems like a solid non-replication.
“ Several parallel scenarios are available, allowing retesting individuals without bias due to experience and learning effects.”
This is a quote from the paper that Scott cited. I wondered the same thing as you; whether a lot of prior knowledge of the test affects performance enough to overcome any problems with CO2 levels
The lesswrong post linked about chess is nearly a good measure but is made much noisier by the confounding factor of "how good is the random anonymous person I happen to be playing today?". Happily chess furnishes a much better measure of day-to-day fluctuations in cognition, which would be to solve chess problems: positions (either taken from real games or artificially composed) in which there is a single, objectively correct answer to the question "What is the winning move here"? This also seems more like "decision-making" than finding as many words as you can in a word-search puzzle in a set period of time.
Does chess have a recognized solution to this? I don't know exactly how Elo ratings work, but it seems to involve adjusting for your opponents' skill (eg you get lots of points for beating someone better than you, and you lose very few points for losing to them). Would "average Elo points gained/lost per match" be a fair measure of how well you're doing that day? Do chess websites make that easy to track?
Oh sure, they can calculate and track this automatically, but a whole game of chess consists of so many decisions that you could feasibly lose to one person on one day because you made 40 great moves and then one dumb move (median cognitive strength: good!), and then beat someone else of exactly the same elo strength the next day by making 40 mediocre moves and then one more move that didn't lose (median cognitive strength: average!). The advantage of solving a single problem (ie choosing a single move by calculating a huge branching tree of variations) is that there is no time limit (it can take half an hour or more if you like) and it's a single decision, so it is arguably a better measure of your peak concentrated cognitive power at that time. (There remains inevitably some subjectivity in how to grade the difficulty of problems though.)
Elo is good for this. Given two players' ratings, you can calculate the probability that one will beat the other. So rather than tracking win/loss or +/- points, you can track if you did better than expected or worse than expected and by how much.
Chess.com also provides an accuracy rating (how closely your moves matched the engine's recommendation). This could work too. The only problem is that if your opponent is much worse than you, it's generally really easy to get high accuracy because the best moves are obvious. But with a decent match-making system I wouldn't expect that to be much of a problem.
I disagree with the other person's puzzle suggestion; some puzzles are just harder than others, and unlike with opponents, there isn't really an objective way to account for that.
I forgot to add -- I've played around with chesscom's API and using it to track the rating info would be easy, but unfortunately you have to pay for accuracy info. You could conceivably track stuff like "number of blunders, mistakes, and inaccuracies per move" by hand for free though.
If anyone does decide to use chess as a marker for cognition, I would recommend ignoring win/loss entirely and focusing entirely on moves. Use stockfish or something to compare scores before and after each move. Proportion of good moves or some other move based transform will be more robust to blunders (by you or your opponent) than game win/loss.
Any chance you can test the correlation against different CO2 sensor noise/bias models? I believe you that low readings happen when you'd expect and high readings happen when you'd expect, but I can imagine observing that even if (CO2 reading) = m*(True CO2 level) + b or even something higher-order.
If X is correlated with a linear transformation of Y, then X is correlated with Y to precisely the same degree. If it's not a linear transformation, then the observed correlation could end up being larger or smaller, but to completely erase a correlation that is in fact strong would likely involve a weird transformation.
I did something similar playing Go against the computer when I worked long overnight shifts in an intellectually focus demanding job. Every few hours I'd play a few quick 9x9 games against the computer and decide based on my resulting rating how well I was mentally handling whatever level of fatigue I was in.
Scott: instead of doing univariate p-tests, why not fit a linear model where you add an extra term that depends on days since you started playing to model your skill increasing over time? I’m happy to fit the model for you if you feel comfortable sharing/uploading the data somewhere.
Done! See http://slatestarcodex.com/Stuff/CO2data.xlsx . You'll want to use "ME AS %" as the dependent variable, that's my score as a percent of the average score for each board. I didn't start recording some thing until later so those columns will be blank until I start. Let me know if you have any other questions.
Hi Scott: short answer - there's absolutely no statistical effect that I can see from any of the variables you specified.
Long answer: here is a COLAB that anyone can run with all your data so they can check my steps, I threw this together pretty quick: https://colab.research.google.com/drive/1R8KBD_3Wvh_0KmI3YMcdzkMve6JXeXJ6?usp=sharing - if you are interested in the summary, it's the final cell at the bottom. As you can see, the total R^2 is pathetic (0.13) and none of the covariates are statistically significant.
Oh, and the final model is: 'normalized_score ~ total_days + minute_of_day_sine + C(day_of_week) + CO2 + temp' - with the C(day_of_week) syntax specifying that I used a dummy encoding to capture any effects from day of week.
Really interesting to see this. I started a company to commercialize a CO2 capture material back in 2014. At the time, a lot of people I talked with were excited about this study, but I was always really suspicious of the effect size.
I was planning to kick of some self-experiments on cognition in a few weeks using chess puzzles, working memory, and math tests. I ordered a CO2 monitor and will add that in to the mix.
Anyone have any other interventions or supplements they think would be interesting to test?
The sleep study just finished and I’ll be unblinding the data and analyzing this weekend. That’s what got me thinking about what my next study would be.
I think that CO2 has a big impact on my productivity, because I seem to get distracted much easier and am less willing to do real work when I spend a longer time in a less ventilated room. (In fact, I am likely to play a game like WordTwist in that scenario :D) But I never measured this with a monitor, so I would be interested how well my notion of distracted-ness really correlates with CO2 levels. I just can't think of a good, unbiased, way of measuring it...
No, that game is just very responsive to practice. I started out getting about a third of average, and after playing it a few thousand times (I only measured carbon dioxide for 800, but played it much more), I'm slightly above average most of the time. Most of the people whose plays are going into that average have been playing it hundreds or thousands of times, and learned all the stupid meaningless words that it accepts as real (some of the most profitable words are short extremely obscure ones using common letters, like telt, lari, esne, and tael). You also need to learn the generation algorithm (about half the time, it inserts s a very long word usually ending in -ness or -tion, so you often want to search for those endings and then try to work back from there). With a little bit of addiction and wasting your potential as a human being, you can become as good as anyone else!
I put significant probability on the hypothesis that cognition responds to fast changes in CO2 concentration, but not to absolute CO2 concentration; ie, if you go from outside to a stuffy room, you'll be mildly impaired for some duration, and if you go from a stuffy room to outside you'll maybe get a boost for some duration (or perhaps an opposite-direction effect which is also some sort of impairment), but if you wait awhile in either environment you'll return to baseline. This is what you'd expect given a homeostatic mechanism that isn't instant. This would reconcile the original results (where people go straight into a high-CO2 room, and do worse) and your results (where you let the CO2 concentration rise at a slow, natural rate).
This makes sense. Blood co2 levels are not primarily driven by air co2, and the health effects of low ventilation that building codes are concerned about use co2 as a proxy for accumulation of volatile organic compounds and other gases, not co2 itself. At least climate change isn’t making us co2 stupid!
I will consider testing it, mostly because the game is fun. But also does anyone have any other circumstances to test this with that could affect intelligence? “Before vs after strenuous exercise”, “while fasting vs while not”, “before vs after big meal”
Oooh what about high vs low air pollution days? Although id expect that to fail too, the negative effects of partial combustion. product pollution is probably longer term. Many possibilities
Would you expect office workers to also do that?
> body instantly abandons all normal priorities and concentrates only on detoxin this
Wow. How is that orchestrated in the body? How does the human body get rid of the toxin?
Is this a similar effect to people developing tolerance to low oxygen/low air pressure conditions? Or maybe actually exactly the same effect (i.e., increased red blood cells in people who are in low oxygen environments for long periods of time?)
How can you "metabolise CO2 better to avoid acid buildup"? The human body doesn't have any non-acidic way to transport it.
As a rule, if the blood bicarbonate buffer shifts towards H+ (excess CO2) your medulla just cranks up your breathing so you blow off more CO2.
I am less impressed with your study than I am with you finding intrapsychically.
I didn't - at the end of the game it tells you all the words you missed.
Is the CO2 in my room really high (possible, even with windows wide open; thanks, wildfires!), or does that word not actually exist in the grid? There is no neighboring "C" and "H" pair on this board.
There's a c on the far right column, and an h to the top left of it, I thought diagonals didn't count at first so I was confused
Extremely cool. One possible way to salvage the original result is if there is a cumulative threshold effect: maybe you need to be in a low-carbon environment for a long time to see effects and if you regularly breathe fresh air your mental function is not affected. This wouldn't explain the submarine data point though
Unfortunately, some of the pro-CO2 papers claim acute effects. Like Satish's experiment used 1 hour of exposure pre-testing (https://ehp.niehs.nih.gov/doi/10.1289/ehp.1104789), and is one of the most-cited ones and has p-values out the wazoo.
The whole concept is silly, IMO. If something we did regularly was messing with our cognition it would be obvious.
I'm not sure it would be that obvious. Recent analysis of court records have shown that judges levelled more severe sentences against guilty offenders the lower their blood sugar, ie. that hungrier they got/closer to lunch, they became hangry. After their lunch their sentencing severity popped back up nearly where they were at the start of the day.
I suppose we'd have to survey lawyers if this was common knowledge, but my understanding is that it wasn't.
The hungry judges story has been debunked. See "Overlooked factors in the analysis of parole decisions". https://doi.org/10.1073/pnas.1110910108
It's an interesting example of a claim that spread through headline repetition, when anything other than headline repetition would have instantly discredited it. The effect size found in the study was a *one hundred percent reduction* in the likelihood of being acquitted as you get closer to lunch.
Without any knowledge of lawyers, I'd say they were aware that the guy scheduled immediately before lunch isn't going to be acquitted, and isn't going to take very long - but that they would have provided the same explanation as all subsequent discussion of the paper has, that the court schedule is not determined at random, and that guy was placed before lunch because he was going to be convicted in a short, predictable amount of time.
Looks like the authors defended it: https://www.pnas.org/content/108/42/E834?utm_source=TrendMD&utm_medium=cpc&utm_campaign=Proc_Natl_Acad_Sci_U_S_A_TrendMD_0
I found something else more recent which found the effect size to be overestimated* though because of the varying length of cases, instead of time of scheduling, so it may still be debunked. That's as far as I'm reading for now, but there's a lot to it. Thanks for sharing that, I hadn't thought to question it before.
But it is obvious: ‘we all know’ that hunger affects our mood. Just like all teachers know that kids are more rowdy just before lunch.
(Remember that “we all know” does not mean it is true.)
Also, it's a long way from "affects our mood" to "affects our mood in this particular way, under this particular circumstance, all other things being equal, x% of the time."
"Go get some fresh air to clear your head" is common advice, so there's definitely something obvious enough to be noticed by regular people.
Definitely worth investigating.
Sure - but like the 'hungry judges' story, the purported effect is just too big.
I recently (June) started monitoring AQ in my condo after reading similar studies, watching a presentation by DHH from Basecamp (MRqh8oLY7Ik) and trying to find ways to help my wife's migraines. I'm using the Awair AQM8002A.
Our overnight CO2 in our bedroom (shared with 3 children) went up as high as 1300ppm and rarely went under 900ppm any time during the day. I tried opening windows and I could push it down to 700 but as soon as I closed the window (since it's July in Houston) it shot right back up. The humidity however took much longer to recover.
We left for a month and it went down to the 400s (set the temperature to 78 instead of 71).
I just used Condensate Pan Treatment Tablets (Uric acid) two days ago and our overnight reading have gone down to high 700s (from 1300ppm). I've had a lot of trouble figuring out how such a large change in CO2 could have been caused by micro-organisms in the condensate pan... My first thought is faulty meter, which I haven't tested.
No way to know the effect on migraines as it's a long term occasional problem. My personal waking fatigue is much improved though.
How did kids 2 and 3 come about with you all sharing a room?
Asking the real questions
Inquiring minds want to know!
I'm still trying to figure out how we managed not to have any more.
A friend’s mom had 9 kids and her favorite line was, “I really gotta find out what’s causing it.”
https://youtu.be/fUspLVStPbk
"We have five children because We Do Not Want Six". - a now-disgraced comedian
"Why do I have fourteen cats? Because I had sixteen cats and two of them died." - Paula Poundstone
apparently some of the cheapo meters actually use VOCs as a proxy for CO2 levels
yeah this is quite common. OP should double-check that it's a real co2 detector (I think the good ones usually use IR)
Yup, mine's a good one. Well calibrated compared to industrial CO2 meters.
Is urban dictionary a valid source of words for the game? Narc…
Could there be factors other than CO2 that correspond to ventilation? Air flow, humidity, level of VOC, sound levels, etc.
I sleep much better with a fan. A study might show that people sleep better with fans running. Headline, “Studies show high air flow helps sleep.” Later we find out it’s the white noise that’s helping.
My CO2 meter tells me humidity, but I didn't think to record it. Guess I've got to play another 800 games now. Good thing I'm addicted.
You should go decide which environmental factors to record for each game in advance so that you don't need to play 800 new games every time someone brings up a random factor that is potentially correlated to intelligence.
Some factors that might be worth recording, in addition to co2 and humidity, in no particular order:
- How much you slept
- VOCs
- Ambient sound level
- Air flow
- Stress (as in how much other stuff you have to do soon)
- Sugar intake
- Lighting
- Screen time
- Commute length
- Obesity?
- Chewing gum
- Watching stupid entertainment shows
- Fluoride
- Meetings
- Secondhand smoke
- Whether you took Ambien/Xanax/etc
Also, random thought: If you don't want to play the word game yourself a bunch of times in order to test hypotheses about human cognition, you might want to ask (some of) us, the vast ACX readership, to do it on your behalf.
Recording for each individual game, how many games immediately prior in a session and how you scored, might not be a bad idea. I get into a zone with my certain computer game and my performance usually improves for a few games in a row, then drops and improves again. If you were playing one game a session you’d always be cold, but if you play in blocks this tendency to temporarily improve might obscure whatever the CO2 was doing to your scores in general. Given a repeated task in the presence of some high but more or less constant level, maybe the brain adapts to the situation at the time.
Also, given that there were other people in the room sometimes, the presence/absence of conversations and/or singing.
This is a great list of metrics, but I'm not sure how I'd measure some of them (e.g. air flow).
If you are modifying the experimental conditions anyway, and there are no budgetary constraints, I'd suggest following additions:
(1) Air oxygen meter.
(2) Get an app that beeps at regular times (or random times could work too) and asks you to record if you feel like playing or not and record the air metrics. Get automated sensor that record the metrics anyway, so it is less work. Maybe you know someone who can hook the sensors into an Arduino board / RasPi?
The previous data from the same location can also be quite useful.
Humidity could be, but I don't think it's likely that it causes the Dutch East India Company.
> I don't think it's likely that it causes the Dutch East India Company.
I also agree with you that humidity is not the ultimate cause of the existence of the Dutch East India Company, but I also think that the phrase "Dutch East India Company" in the above comment is a malapropism.
I think they're making fun of you and BronxZooCobra for using the acronym "VOCs" without ever explaining what it means, since VOC was also the acronym for the Dutch East India Company.
Google suggests "Volatile Organic Compounds". I assume it's something along the lines of pollen count.
Not pollen, more like butane, propane, off gassing from paints, fumes from pumping gas, etc.
You might find this amusing, if you haven't heard of it before: There's an urban legend that sleeping with a fan can kill you. https://en.wikipedia.org/wiki/Fan_death
(I also sleep with a fan. It hardly ever kills me.)
It can lead to career death for artists these days.
This is a great joke.
Some spaniard scientist seemed pretty alarmed by the effects of infrasound on airplane crews´ blood vessels at one fascia congress and advised to shun computer fans. But that was at a conference years ago and today I guess there's not much behind it.
My anecdotal evidence is that I feel better and more alert when I ventilate the car on long drives. But in car CO2 levels be much higher than a house or apartment. I can’t think of a good way to test this.
The carbon monoxide might be playing a role in the car situation.
I had wanted to measure this exact same thing - ever since I moved into my current flat I feel that I can work so much better with the windows open. And the price did stop me - I thought these monitors were around $10 when I got the idea (why do they cost so much?). So... if logistics of me being in the UK is not an issue, I'd be happy to test?
Send me an email at scott@slatestarcodex.com with your planned experimental protocol (doesn't have to be too official) and your address and we can talk about it.
If you're actually willing to buy the monitor for someone(s), I suspect you'll find plenty of video game streamers who would be willing to do this as a gimmick on their stream for some weeks, so then you'd just have to decide which game(s) you think are more "cognitition" focuses.
If any streamers are reading this and willing to work with me here, let me know.
I'm a streamer. https://www.twitch.tv/nebupookins I'm open to playing a wide variety of games on stream (except I don't like to play horror games). I've also bought two CO2 monitors after reading this post (not the one you recommended, a $30 one and a $50 one) with the expectation that if they both report the same reading, they're probably both accurate, but if they report different things, then one (or both) of them are inaccurate.
I'm really curious if you have some suggestions for experimental protocol.
Are you playing any competitive online games? Overwatch, League of Legends, Starcraft? Those usually have pretty detailed statistics for player performance. I play LoL and third party apps like Porofessor show me very detailed stats per match, from "teamfight participation %" to "creeps farmed per minute". But to avoid multiple comparison adjustments, I'd just stick with measuring competitive score progression. If you gain more points when playing in the fresh room than in the stuffy room, this is good evidence for the effect.
I'm streaming too sometimes, a mix of Russian and English streams, gaming and photo editing. https://www.twitch.tv/loweren
I used to play League, but my performance in League already has insanely large variance so not sure it'd be a great metric for me. E.g. creeps per minute varied by a factor of 18.5.
A lot of recent top-level chess has been sponsored by an air quality monitoring company who used this gimmick. Eg you can see it at 1h30m here: https://youtu.be/EmVuLy08Y4k. The commentators sometimes mention it too, in order to help the sponsor.
If any streamers are reading this: I would find this gimmick pretty entertaining, and would direct some money/views toward a streamer who did this in an at-least-moderately-careful way.
How would you make it fun without unblinding the gamer about CO2 levels? Or maybe blinding is asking too much since people can usually sense low oxygen anyway.
People can't sense low O2 - that's why simple asphyxiants like nitrogen and the noble gases can kill. What we sense is high CO2 directly.
(Simple asphyxiants are dangerous because breathing them doesn't give O2 but does remove CO2 - as such, you don't sense "bad air", you just pass out from lack of oxygen and then die.)
Fair point, I’d learned that and then forgot it. But yeah replace low O2 with high CO2 in my post.
Confused though, nitrogen and noble gases aren't converted to CO2 by the body right? Is this part of why CO is so bad? CO would be converted to CO2. Though CO binds to hemoglobin so strongly this effect is probably negligible for CO.
What's the mechanism for this exactly? How do we sense the high CO2 that makes us want to breathe out? CO2 is pretty inert. Is it through CO2 acidifying water? If I put another gas that acidifies water in the air does your body start to process it as CO2, and will you have trouble even if there is enough O2 in the air?
Lots of questions, but would like more explanation here!
I'm speaking about the case where you're breathing pure N2 (or another gas/mixture that while not toxic does not contain O2).
If you're breathing pure N2, you will indeed maintain low levels of CO2 and not be poisoned by it. However, you need a constant supply of O2 in order to live, and pure N2 by definition doesn't have any. As such, after a couple of minutes of breathing pure N2 you will pass out from lack of oxygen (and then die unless rescued).
This form of asphyxiation (no CO2 accumulation, just lack of O2) can only occur if you are breathing gas with low CO2 and also low O2 - this is highly unusual, because "bad air" breathed out by other animals will reach dangerous levels of CO2 long before the amount of O2 drops to insufficiency (40,000 ppm of CO2 is 100x current baseline/150x pre-industrial and immediately dangerous to human health, but that's only 4%; animals use something like 1-1.5x as much O2 as they produce CO2, but even a 6% drop in O2 from the 20% baseline is still 14% - more than half of it is still there). The usual cases for sudden anoxia are sudden decompression of a plane, huffing helium balloons, SCUBA accidents or improper storage of cryogenically-liquified gases - to put it mildly, not the conditions natural selection designed us for.
I'm not 100% sure of the way by which we sense high CO2. I do know that strongly-acidic gases like HCl, NO2 or SO3 are very dangerous to breathe, although this has more to do with direct acid damage to the lungs than with homeostatic errors.
Cool! What's the mechanism by which CO2 is dangerous? If I breathe in something is just like air except with the CO2 in place of the nitrogen, so the oxygen content is still good, what happens exactly? Acidification, some of reaction A + B <-> CO2 + X where the equilibrium is off, something else? Why would I die? Isn't CO2 a relatively inert gas?
It is one of the cases where evolution cuts corners that no good engineer would: it tests something easy (CO₂ → acidity was my guess too) that is strongly correlated *in nature* with the thing it needs to test (O₂).
I learned recently (although I would need confirmation) another example: water. We feel thirsty when we need water, and we get minerals at the same time. We do not have a feeling for the lack of these minerals. Therefore, drinking distilled water will sate our feeling of thirst, but will not supply our body all it needs.
CO is bad because it binds to the heme group in hemeglobin better than O2, so it will displace O2. That is, your red blood cells will absorb CO before they absorb O2. It also induces a conformational change in hemoglobin that inhibits oxygen unloading, so even the O2 that is left isn't delivered efficiently to tissues. CO2 doesn't bind to hemoglobin at all, it's quite a different looking molecule.
Yes, the main sensors controlling breathing in the brainstem sense H+, which increases with CO2 levels because dissolved CO2 largely forms carbonic acid by interaction with water. There are additional sensors that directly detect O2 levels also.
Acidifying blood per se is not thought to trigger increased breathing, because the detectors are actually sensitive to H+ in the cerebrospinal fluid, so something has to cross the blood-brain barrier (which H+ cannot) and *then* cause a decrease in pH. CO2 does that.
Very cool. So, is there any other gas that makes a weak acid and achieves the same effect? I'm thinking about SO2 (which is nontoxic right) for instance. SO2 also gives you the acidification thing? You don't have the A+B <-> X + SO2 thing though.
Haemoglobin does bind CO2, via the N-terminal amino group (which can be carbaminated). It's a minority of the blood's transport capability, and it certainly doesn't involve the haem site, but it's not correct to say Hb doesn't bind CO2.
Don't need to worry about which are more "cognition" focused. Cover a wide array of genres and stream types and see if any have a marked effect. If the effect is indeed specific to a certain kind of decision making, this could tease out what it is.
Personally, I feel like there *might* be an effect for tasks that depend heavily on what people call "emotional intelligence" (scare quotes), but not for anything else (unless you want to talk about long-term carbon dioxide overexposure or something, which is a different topic).
Or for things that are tedious.
That could work too, but I feel like that might go away for tasks you're familiar with, so it might be impossible or hard to test.
Yeah I'm wondering about coming up with new ideas vs repetitive things. Again this is because a lot of people come up with new ideas while outside walking, and my suspicion is that the mechanism for this is probably not CO2 but it's a reason the CO2 hypothesis sounded plausible to me. I also feel I can focus better when the window is open, but it could just be a placebo effect or it could be that the sound from outside is some sort of white noise, or that having some change in the background stimulates new ideas (maybe it's extra hard to work and come up with new ideas while staring at a white wall) or something else I don't know.
I think there is a lot of interesting stuff in this space that is chronically under-explored, and which needs more empirical data so we can all figure out how to work more efficiently. This seems like a pretty underfunded direction of research...
It would also be interesting to see if there is a "natural" way to split various human activities, and whether differential effects on how well we can do them from various outside influences can be used to classify them. So is there some way in which tasks A,B are more alike to each other than C,D, in that A,B both become harder under circumstance X but not C,D? It would also be interesting to look at the corresponding brain activity while doing all of these but this would be hard unless you had some kind of mobile pocket MRI machine.
Again I think there are a lot of interesting questions here. We should try to understand them better because the upside could be potentially ginormous.
Nice self-replication! And I'm pretty convinced by your successive ruling-out of explanations as to why the effect is real but you failed to detect it (e.g., controlling for temperature).
Sorry if you mentioned this and I missed it, but is there any chance that time (like "index" of the trial/game) was a factor? Like, maybe you got better at the game over each successive play, but CO2 levels were also positively correlated with time? In which case you might mask a "real" effect of CO2 if performance is driven by Time (+) and CO2 (–). As you say, to salvage the effect you'd need for these effects to be of roughly the same size, which is a stretch. But might be worth checking.
Another possibility would be that you're already so good at the game that you're essentially at ceiling, so there's just not enough variation in your performance to explain, even though you observe plenty of variation in CO2 levels.
I don't love this explanation because to take it seriously, you'd need an account where the influence of CO2 is dependent on prior ability in the task. Basically an interaction between Expertise and CO2 on Performance, such that High Expertise is somehow "immune" and Low Expertise is more susceptible to CO2 levels. I guess this is in principle possible, especially if the task is easy enough for people with high verbal reasoning/fluency. But: 1) it doesn't seem that intuitive to me; 2) if it is true it's a pretty big caveat for the initial results, and implies they must've sampled from Low Expertise population to have detected an effect (assuming they didn't regress out Expertise); and 3) now we're just adding epicycles.
If you mean getting better over successive games over the course of months, this is definitely happening, but CO2 isn't changing consistently (other than I guess in the global warming way, which is much slower). If you mean getting better over successive games in the course of a sitting, I have the data that would let me test for that but I haven't done it - just eyeballing it it doesn't look that way, nor does CO2 go up very much over the course of my sittings (I usually play only 3 or 4 games max in a sitting, which takes about 15 minutes, which isn't enough time for room CO2 to increase much)
I'm definitely not at the ceiling - my "score" (which I calculate artificially as score divided by average score for the board) has varied between 54% (my worst game) and 143% (my best) over the past month. The world record for most boards is often around 2x my own score.
Yeah I meant the former ("getting better over the course of months")––I just thought maybe if time was correlated with wildfire season or something, you might detect higher CO2 levels. But that makes sense! Seems like a solid non-replication.
“ Several parallel scenarios are available, allowing retesting individuals without bias due to experience and learning effects.”
This is a quote from the paper that Scott cited. I wondered the same thing as you; whether a lot of prior knowledge of the test affects performance enough to overcome any problems with CO2 levels
The lesswrong post linked about chess is nearly a good measure but is made much noisier by the confounding factor of "how good is the random anonymous person I happen to be playing today?". Happily chess furnishes a much better measure of day-to-day fluctuations in cognition, which would be to solve chess problems: positions (either taken from real games or artificially composed) in which there is a single, objectively correct answer to the question "What is the winning move here"? This also seems more like "decision-making" than finding as many words as you can in a word-search puzzle in a set period of time.
Does chess have a recognized solution to this? I don't know exactly how Elo ratings work, but it seems to involve adjusting for your opponents' skill (eg you get lots of points for beating someone better than you, and you lose very few points for losing to them). Would "average Elo points gained/lost per match" be a fair measure of how well you're doing that day? Do chess websites make that easy to track?
Oh sure, they can calculate and track this automatically, but a whole game of chess consists of so many decisions that you could feasibly lose to one person on one day because you made 40 great moves and then one dumb move (median cognitive strength: good!), and then beat someone else of exactly the same elo strength the next day by making 40 mediocre moves and then one more move that didn't lose (median cognitive strength: average!). The advantage of solving a single problem (ie choosing a single move by calculating a huge branching tree of variations) is that there is no time limit (it can take half an hour or more if you like) and it's a single decision, so it is arguably a better measure of your peak concentrated cognitive power at that time. (There remains inevitably some subjectivity in how to grade the difficulty of problems though.)
In fact ELO assumes that anyone can beat anyone, just with different probabilities.
Well sure, this is how it's possible to increase one's elo by beating someone with a higher rating.
Elo is good for this. Given two players' ratings, you can calculate the probability that one will beat the other. So rather than tracking win/loss or +/- points, you can track if you did better than expected or worse than expected and by how much.
Chess.com also provides an accuracy rating (how closely your moves matched the engine's recommendation). This could work too. The only problem is that if your opponent is much worse than you, it's generally really easy to get high accuracy because the best moves are obvious. But with a decent match-making system I wouldn't expect that to be much of a problem.
I disagree with the other person's puzzle suggestion; some puzzles are just harder than others, and unlike with opponents, there isn't really an objective way to account for that.
I forgot to add -- I've played around with chesscom's API and using it to track the rating info would be easy, but unfortunately you have to pay for accuracy info. You could conceivably track stuff like "number of blunders, mistakes, and inaccuracies per move" by hand for free though.
You'd use performance rating and this would be easy to track via information from a chess website.
If anyone does decide to use chess as a marker for cognition, I would recommend ignoring win/loss entirely and focusing entirely on moves. Use stockfish or something to compare scores before and after each move. Proportion of good moves or some other move based transform will be more robust to blunders (by you or your opponent) than game win/loss.
Any chance you can test the correlation against different CO2 sensor noise/bias models? I believe you that low readings happen when you'd expect and high readings happen when you'd expect, but I can imagine observing that even if (CO2 reading) = m*(True CO2 level) + b or even something higher-order.
I don't know what this means. If you think you can do it with the raw data, I can send you the raw data.
Nah, Kenny convinced me. Thanks for replying though :)
If X is correlated with a linear transformation of Y, then X is correlated with Y to precisely the same degree. If it's not a linear transformation, then the observed correlation could end up being larger or smaller, but to completely erase a correlation that is in fact strong would likely involve a weird transformation.
I did something similar playing Go against the computer when I worked long overnight shifts in an intellectually focus demanding job. Every few hours I'd play a few quick 9x9 games against the computer and decide based on my resulting rating how well I was mentally handling whatever level of fatigue I was in.
Scott: instead of doing univariate p-tests, why not fit a linear model where you add an extra term that depends on days since you started playing to model your skill increasing over time? I’m happy to fit the model for you if you feel comfortable sharing/uploading the data somewhere.
Done! See http://slatestarcodex.com/Stuff/CO2data.xlsx . You'll want to use "ME AS %" as the dependent variable, that's my score as a percent of the average score for each board. I didn't start recording some thing until later so those columns will be blank until I start. Let me know if you have any other questions.
Excellent! Will take a stab at it this evening and post the results asap.
Hi Scott: short answer - there's absolutely no statistical effect that I can see from any of the variables you specified.
Long answer: here is a COLAB that anyone can run with all your data so they can check my steps, I threw this together pretty quick: https://colab.research.google.com/drive/1R8KBD_3Wvh_0KmI3YMcdzkMve6JXeXJ6?usp=sharing - if you are interested in the summary, it's the final cell at the bottom. As you can see, the total R^2 is pathetic (0.13) and none of the covariates are statistically significant.
Oh, and the final model is: 'normalized_score ~ total_days + minute_of_day_sine + C(day_of_week) + CO2 + temp' - with the C(day_of_week) syntax specifying that I used a dummy encoding to capture any effects from day of week.
Really interesting to see this. I started a company to commercialize a CO2 capture material back in 2014. At the time, a lot of people I talked with were excited about this study, but I was always really suspicious of the effect size.
I was planning to kick of some self-experiments on cognition in a few weeks using chess puzzles, working memory, and math tests. I ordered a CO2 monitor and will add that in to the mix.
Anyone have any other interventions or supplements they think would be interesting to test?
Thanks for the preregistration!
Np. I will post my protocol and planned analysis before I start, similar to what I did for my sleep study (https://www.quantifieddiabetes.com/2021/07/melatonin-to-stay-asleep-longer.html).
The sleep study just finished and I’ll be unblinding the data and analyzing this weekend. That’s what got me thinking about what my next study would be.
I think that CO2 has a big impact on my productivity, because I seem to get distracted much easier and am less willing to do real work when I spend a longer time in a less ventilated room. (In fact, I am likely to play a game like WordTwist in that scenario :D) But I never measured this with a monitor, so I would be interested how well my notion of distracted-ness really correlates with CO2 levels. I just can't think of a good, unbiased, way of measuring it...
Whelp, found out that I suck at word games today
No, that game is just very responsive to practice. I started out getting about a third of average, and after playing it a few thousand times (I only measured carbon dioxide for 800, but played it much more), I'm slightly above average most of the time. Most of the people whose plays are going into that average have been playing it hundreds or thousands of times, and learned all the stupid meaningless words that it accepts as real (some of the most profitable words are short extremely obscure ones using common letters, like telt, lari, esne, and tael). You also need to learn the generation algorithm (about half the time, it inserts s a very long word usually ending in -ness or -tion, so you often want to search for those endings and then try to work back from there). With a little bit of addiction and wasting your potential as a human being, you can become as good as anyone else!
o7
I put significant probability on the hypothesis that cognition responds to fast changes in CO2 concentration, but not to absolute CO2 concentration; ie, if you go from outside to a stuffy room, you'll be mildly impaired for some duration, and if you go from a stuffy room to outside you'll maybe get a boost for some duration (or perhaps an opposite-direction effect which is also some sort of impairment), but if you wait awhile in either environment you'll return to baseline. This is what you'd expect given a homeostatic mechanism that isn't instant. This would reconcile the original results (where people go straight into a high-CO2 room, and do worse) and your results (where you let the CO2 concentration rise at a slow, natural rate).
That's a good point, and maybe I'll try testing it sometime.
This makes sense. Blood co2 levels are not primarily driven by air co2, and the health effects of low ventilation that building codes are concerned about use co2 as a proxy for accumulation of volatile organic compounds and other gases, not co2 itself. At least climate change isn’t making us co2 stupid!
I will consider testing it, mostly because the game is fun. But also does anyone have any other circumstances to test this with that could affect intelligence? “Before vs after strenuous exercise”, “while fasting vs while not”, “before vs after big meal”
Oooh what about high vs low air pollution days? Although id expect that to fail too, the negative effects of partial combustion. product pollution is probably longer term. Many possibilities