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Adults with history of recreational cannabis use have altered speech production

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Re: Adults with history of recreational cannabis use have altered speech production

#61
post #59

Earlier quoted context omitted.

The sample size was also 31 users, 40 controls. This really isn't a meaningful result.

I don't really participate in scientific literature or journals, but I see a lot of notes in HN around papers that appear to be overblowing the significance of their findings. Is there a way for researchers to publish 'interesting observations' as just that, something that they measured that may or may not be noteworthy but felt worth sharing with the broader community?

The traditional solution to this problem is to insert a paragraph in the conclusion saying something along the lines of "this merits further study". However, that particular phrase has been overused in journal articles, to the point that it doesn't mean anything anymore.

Re: Adults with history of recreational cannabis use have altered speech production

#62
>Differences between groups may reflect longer term changes to the underlying neural control of speech.

A simpler hypothesis: Cannabis smoke is hot and messes with your throat. No need to invoke mysterious neural changes. See also: links between hot beverage consumption and throat cancer.

Re: Adults with history of recreational cannabis use have altered speech production

#64

Earlier quoted context omitted.

That is the reason they gave publicly, not the reason they don't like the study. The study used participants without a history of other drug use. And having the effect appear with only 31 randomly sampled users means the effect is easy to detect. This is a normal number of participants for this sort of study. You see this sort of motivated reaction to a study every time there is one that triggers a population.

" You see this sort of motivated reaction to a study every time there is one that triggers a population. " This is true, but in both directions. Because unlike you said, they actually only tested 31 cannabis users against a controll group of 40. And found that maybe subtle differences exist. "Speech samples were collected from a carefully described cohort of 31 adults with a history of cannabis use (but not use of il…

> they actually only tested 31 cannabis users against a controll group of 40

This is exactly like I said. In fact nothing you say contradicts anything I've said, so I'm not sure what point you're trying to make.

Adding more participants would measure the same subtle difference with increasing precision, but it's unclear what the point of that would be.*

The next logical step is to look further into voice effects, since the voice effect (along with the similar motor effects) are just easily measurable proxies for other changes going on in the brain.

Generally, if one's criticism of a study uses only concepts you learn about in the first day of intro to statistics (e.g. "correlation does not imply causation" or "there are only N participants"), then chances are pretty low that one has discovered a serious flaw that was missed by the authors and reviewers.

*We can get into a wider discussion about power here, but that tends to be pretty subtle and nothing at all about the power of the study merits it being called absurd.

Re: Adults with history of recreational cannabis use have altered speech production

#65
post #62

>Differences between groups may reflect longer term changes to the underlying neural control of speech. A simpler hypothesis: Cannabis smoke is hot and messes with your throat. No need to invoke mysterious neural changes. See also: links between hot beverage consumption and throat cancer.

I've been a recreational Cannabis smoker for almost 20 years, since I was 14, and smoking it 100% has a noticeable effect on my speech. People, also stoners mind you, will make fun of me for it because of the level of effects it has on me. For instance, they would say I'm actually a model for why people shouldn't smoke pot (again these are users). Anyway, these effects go away with abstinence, but generally take up to a month to really go away (not that I've had many breaks that long in the last 20 years). Yes, weed effects my speech, but also other activities that involve hand-eye coordination or heavy thinking, such as sports, video games, programming, learning mathematics, etc. It's not a huge stretch of the imagination (and a theory supported by research) that short term neurochemical changes will result in longer term structural, i.e. syntactical, changes in the brain. There is a lot understood about this type of mechanism (I did a PhD in computational neuroscience, so I've seen and understood the research in this area).

Re: Adults with history of recreational cannabis use have altered speech production

#66
post #4

The title seems like a stretch since they then go on to say, "Audio samples were analysed objectively using acoustic analysis for measures of timing, vocal control, and quality. Subtle differences in speech timing, vocal effort, and voice quality may exist between cannabis and control groups, however data remain equivocal." "After controlling for lifetime alcohol and tobacco use and applying a false discovery rate, o…

> You'd get the same intensity out of a group of tired people too

That would be interesting too, since AFAIK weed helps with sleep and gets you more deep sleep, but at the cost of REM sleep. There's a lot of theories tossed around as to what that can do to people, but I found it hard to find something solid in that area.

Re: Adults with history of recreational cannabis use have altered speech production

#67
post #22
post #6

Could it have anything to do with subcultural differences among cannabis users and not deleterious physical effects of consumption?

Just seeing the headline, my first thought was, "NEWS FLASH: recreational cannabis users 30% more likely to say 'dude'!"

Next up: "How bats shape our voice. We analyzed voice recordings of 100 baseball and 100 cricket players"

Re: Adults with history of recreational cannabis use have altered speech production

#68
post #31

Not convinced a sample size of 31 is enough, but imagine the implications of a ML model that can detect if you’ve used cannabis recently. Seems like a privacy nightmare.

Well, the first thing I thought upon reading the headline is someone somewhere is going to build an AI based on this and there will be false positives and it'll suck.

Re: Adults with history of recreational cannabis use have altered speech production

#69

Earlier quoted context omitted.

" You see this sort of motivated reaction to a study every time there is one that triggers a population. " This is true, but in both directions. Because unlike you said, they actually only tested 31 cannabis users against a controll group of 40. And found that maybe subtle differences exist. "Speech samples were collected from a carefully described cohort of 31 adults with a history of cannabis use (but not use of il…

> they actually only tested 31 cannabis users against a controll group of 40 This is exactly like I said. In fact nothing you say contradicts anything I've said, so I'm not sure what point you're trying to make. Adding more participants would measure the same subtle difference with increasing precision, but it's unclear what the point of that would be.* The next logical step is to look further into voice effects, sin…

"nothing at all about the power of the study merits it being called absurd. "

Well, I have not read the paper in detail, because I do not want to buy it. So I would not claim it to be absurd in its whole. But what I can read is that the title of it makes a factual statement, while in the text you find the word "maybe". So "absurd" might be fitting for that.

And 31 is a really, really low number, for the goal:

"The aim of this study was to investigate speech in individuals with a history of recreational cannabis use compared to non-drug-using healthy controls. "

Like others have said, there is a strong influence of subculture speech patterns.

Have 10 rastafarie influenced people in the group and sure you will notice difference in the speech pattern. And difference does not necessarily mean "worse". I would have to read the paper to judge what they exactly meassured. And of course, how much the "recreational use" of the person involved was. Because intuitivly: sure, a person smoking 10+ joints a day speaks different, if at all, compared to the normal person.

Re: Adults with history of recreational cannabis use have altered speech production

#70
The real question is are the audio samples publicly available?

> only spectral tilt (vocal effort and intensity)

I can sort of picture what 'vocal effort' & 'intensity' mean but they are assumptions. Really would be nice to have some examples.

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