Effect of LSD on reinforcement learning in humans (2022) • Hacker News Board

Re: Effect of LSD on reinforcement learning in humans (2022)

#31

Post by sva_ » Sun, May 07, 2023, 1:27 PM UTC

riedel wrote: post #2

No expert, but I had some immediate questions when reading this. Wasn't the dose high enough to be easily distinguishable from the placebo without any experience? Why not some other drug a palcebo? Is single blind design actually advisable in such a study? Can someone enlighten me?

Placebos in psychedelics studies are rightfully often laughed about, but if the placebo group never took LSD before, it may indeed not be obvious to them if they got the drug or not.

Re: Effect of LSD on reinforcement learning in humans (2022)

#32

Post by droopyEyelids » Sun, May 07, 2023, 1:32 PM UTC

elif wrote: post #28

It's humorous to me that they bothered injecting saline into the control group here. I'm pretty sure anyone on earth would know whether or not they were on 75 micrograms of LSD, and the act of wondering whether you are or not is enough to induce panic. Pretty sure both groups would produce higher quality data in an unblinded study.

This isnt necessarily true. There is some study out there where subjects were either given saline, or a moderate dose of LSD, and it was only like 60% of subjects were able to tell which was which.

Re: Effect of LSD on reinforcement learning in humans (2022)

#33

Post by andrewinardeer » Sun, May 07, 2023, 1:35 PM UTC

kweingar wrote: post #6

Buhljingo wrote: post #3

Would love to see this type of experiment performed across different dosages, 25 μg -200 μg. I think the "positive" effects would take a big, sudden drop after a certain threshold

Where can I sign up to participate in a study that involves taking 200 ug of LSD? :)

CIA

Re: Effect of LSD on reinforcement learning in humans (2022)

#34

Post by diydsp » Sun, May 07, 2023, 2:01 PM UTC

sva_ wrote: post #31

riedel wrote: post #2

No expert, but I had some immediate questions when reading this. Wasn't the dose high enough to be easily distinguishable from the placebo without any experience? Why not some other drug a palcebo? Is single blind design actually advisable in such a study? Can someone enlighten me?

Placebos in psychedelics studies are rightfully often laughed about, but if the placebo group never took LSD before, it may indeed not be obvious to them if they got the drug or not.

Also people vary on response to all pharmas. Some are simply "hardheads." [0] And this can vary with concomitant medications. So it's inportant to capture these results.

[0] not the most scientific reference but the term "hardhead" is useful here: https://www.shroomery.org/forums/showflat.php/Number/1446930...

Re: Effect of LSD on reinforcement learning in humans (2022)

#35

Post by retrac » Sun, May 07, 2023, 2:01 PM UTC

sva_ wrote: post #31

riedel wrote: post #2

No expert, but I had some immediate questions when reading this. Wasn't the dose high enough to be easily distinguishable from the placebo without any experience? Why not some other drug a palcebo? Is single blind design actually advisable in such a study? Can someone enlighten me?

Placebos in psychedelics studies are rightfully often laughed about, but if the placebo group never took LSD before, it may indeed not be obvious to them if they got the drug or not.

The potency of the placebo effect with psychoactive drugs is pretty remarkable. It also illustrates an interesting effect about the cultural influence on intoxication. It's one of the more easily repeatable placebo experiments.

If you give a bunch of young adults who have never drunk alcohol some "alcohol" and then observe them, they both a) act drunk b) act drunk, according to their expectations about alcohol. (People who report that they believe alcohol makes people more social act more social, those who report that they believe it makes people withdrawn, become morose, etc.)

Another repeated finding, in both placebo and non-placebo groups, is that the alcohol takes effect before it would... take effect. People change behaviour almost immediately. I've noticed that with a drink myself; I'm feeling the drink before I possibly could have absorbed it. It also works the other way too -- a group of actually drunk people behave more sober when you've told them it was just rum-flavoured water, not actual alcohol.

Re: Effect of LSD on reinforcement learning in humans (2022)

#36

Post by tambourine_man » Sun, May 07, 2023, 2:17 PM UTC

elif wrote: post #28

It's humorous to me that they bothered injecting saline into the control group here. I'm pretty sure anyone on earth would know whether or not they were on 75 micrograms of LSD, and the act of wondering whether you are or not is enough to induce panic. Pretty sure both groups would produce higher quality data in an unblinded study.

Placebo is a powerful drug

Re: Effect of LSD on reinforcement learning in humans (2022)

#37

Post by 2devnull » Sun, May 07, 2023, 2:58 PM UTC

retrac wrote: post #35

sva_ wrote: post #31

Earlier quoted context omitted.

Placebos in psychedelics studies are rightfully often laughed about, but if the placebo group never took LSD before, it may indeed not be obvious to them if they got the drug or not.

The potency of the placebo effect with psychoactive drugs is pretty remarkable. It also illustrates an interesting effect about the cultural influence on intoxication. It's one of the more easily repeatable placebo experiments. If you give a bunch of young adults who have never drunk alcohol some "alcohol" and then observe them, they both a) act drunk b) act drunk, according to their expectations about alcohol. (Peop…

I suspect the placebo effect has limited duration for those who are experienced with psychedelics. I can imagine wrongly thinking you’ve been dosed for about 90 minutes, but after that one would surely know, at least for LSD.

Re: Effect of LSD on reinforcement learning in humans (2022)

#38

Post by stephenitis » Sun, May 07, 2023, 3:14 PM UTC

tiku wrote: post #9

I'm more scared of LSD than ever before, after hearing about that you see "scanlines" for ever after using it. Anyone got this after? https://www.insider.com/9-years-after-acid-trip-man-has-pers...

You can test your LSD. I think this is a key part missing in many horror stories. They didn't have clarity in what they were using. In Vienna they have a peg that will use a mass spectrometer and also give you a estimate on the strength of your tab. Very amazing form of harm reduction.

Re: Effect of LSD on reinforcement learning in humans (2022)

#39

Post by bentt » Sun, May 07, 2023, 3:16 PM UTC

elif wrote: post #28

It's humorous to me that they bothered injecting saline into the control group here. I'm pretty sure anyone on earth would know whether or not they were on 75 micrograms of LSD, and the act of wondering whether you are or not is enough to induce panic. Pretty sure both groups would produce higher quality data in an unblinded study.

Were the subjects told “this is LSD” or were they told “this may be LSD and it may be a placebo”?

Re: Effect of LSD on reinforcement learning in humans (2022)

#40

Post by perrylaj » Sun, May 07, 2023, 3:22 PM UTC

bentt wrote: post #39

elif wrote: post #28

It's humorous to me that they bothered injecting saline into the control group here. I'm pretty sure anyone on earth would know whether or not they were on 75 micrograms of LSD, and the act of wondering whether you are or not is enough to induce panic. Pretty sure both groups would produce higher quality data in an unblinded study.

Were the subjects told “this is LSD” or were they told “this may be LSD and it may be a placebo”?

I'm not sure how global the practice is, but at least in the US, you're briefed on the study as part of patient consent. They clearly tell you that nature of the study, including details about blinding, placebos that study participants may get instead of the active chemical, etc.