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Simple fragrance method boosts cognitive capacity: study (scitechdaily.com)
112 points by oblib on Sept 3, 2023 | hide | past | favorite | 58 comments


Weak science.

They ran a battery of 12 tests and looked for one with a statistically significant difference at the 5% level.

If there were no actual differences, how many tests would you need to run to find at least one that by chance shows significance? If you run 20, you’d expect 5% to do so, on average, which is 1. Running 12 and finding 1 is not a significant finding.

Then, suspiciously, the only statistically significant cognitive test improvement they found was on trial 5 of a verbal learning test, which showed little to no improvement on any of the other trials. That makes no sense.

Finally the brain changes had a p-value of 0.046, which is barely significant by even the weak 5% threshold, and the brain changes weren’t correlated with the test result improvements.

Perhaps interesting, but only if replicated.



Good point but anecdotally I think there is something here. Most of us have the experience at some point in our lives when an unusually-encountered smell evokes an event or earlier period in our lives. Many people report that this then links to a further array of memories. Nothing unusual about this. Proust famously described this in his extensive magnum opus 'Remembrance of Things Past' and so have many other authors to a lesser degree. So it's more than 'perhaps interesting'; there's plenty of circumstantial evidence that exposure to such chemicals might work to renew lapsed connections.


Reminds me of the 1963 Czech SciFi film ''Ikarie XB 1'' and how deep space crew members used olifactory cartridges somewhat cigarette-like, triggering memories and stimulating earthly sensations. Fast forward to 15:48 for one of those scenes lasting about 1 minute:

https://archive.org/details/ikarie-xb-1-1963

It seems to me a market will be there if UCI's fragrance method is safe and inexpensive.


Here's a paper on the effects of rosemary on long term memory [1]. And a great video explaining how aromatherapy is believed to work [2]. After I saw these, I went and bought a bottle of rosemary extract and was surprised to find out it smell exactly like VapoRub to me (even though it doesn't contain any).

1. https://www.sciencedirect.com/science/article/pii/S2314808X1...

2. https://youtu.be/zackfqlOwZ4


> The key analysis was a 2 × 2 mixed ANOVA with Time (Pre vs. Post) as the repeated (within subjects) measure and Group (Control vs. Treated) as the across-subjects measure. Given the matching of other variables including age, gender and years of education, we did not include these variables as covariates in the model. A two-sided P less than 0.05 was considered statistically significant. We used SAS9.4 for all statistical analyses.

Can anyone explain why is it reasonable to assume normality here?


I am not sure about this specific case, but I want to point out that there is a big misunderstanding with this normality assumption in t tests: it's not the distribution of the data that needs to be ~normal, but rather the distribution of the sample mean, which usually is ~normal, thanks to the central limit theorem.

https://journals.physiology.org/doi/full/10.1152/advan.00064...


Smell as a trigger for childhood memories in very old people is well known. All kinds of smells: horse poo for instance, woke up some very apathetic older people to talk about their memories of time before cars were common.


This does not seem related to this thread except that it involves smell.


It is a temporary boost of their cognitive capacity. People who are non-verbal have often slid a long way down towards dementia, and bringing it back by evoking deeper well seated childhood memory unlocks the last vestiges of capacity to talk, to sing, to dance. (it happens with music from their childhood too)

I think it relates more strongly to this thread than you, but perhaps I am wrong?


Do you have an example of someone who had dementia and was non-verbal that smelled something then was able to talk, sing and dance?


Isn't that study financed by P&G aka maker of Febreeze?


Yes, Procter & Gamble funded it. That seems to like something they might and should be interested in.

Personally, I realized at a young age I was very affected by some fragrances and perfumes. I got vicious headaches and felt sickened when exposed to some of those. It was especially bad at some stores that doused their store with fragrances, and in Churches where both men and women would slather fragrances on themselves before going there.

They didn't bother my wife and daughters at all though and I finally had to demand they stop using them in our house.

Because of that I learned to gtfo of places as soon as I walked in and smelled it. And I started buying my wife and daughters pure Rose Oil because that actually made me feel pretty good when I got a few whiffs of it, and they all loved that.

Apparently I was not even close to alone with those adverse reactions because around mid 2000s stores began to quit doing that and I very seldom detect those toxins when I go in stores now.

I never found out exactly what was that affected me, but it was sure vicious. I think it may have been some sort of "bonding agent" that made fragrances "stick" better and last longer.

Procter & Gamble sells a lot of stuff with fragrances in them. It behooves them to make sure their products are not sickening folks and, if they can, provide some real benefit.


I'm absolutely with you. Perfumes, new cars, things with artificial smells can really get me.


New car smell is actually all harmful outgassing from plastic so not without reason.


This is a frequent midbrow complaint, but it doesn't matter who funds studies as long as they're correctly constructed.

Especially because otherwise you won't get the studies because nobody else cares.


> This is a frequent midbrow complaint…

I’ve never really thought of attention to conflict of interest in terms of high, low and midbrow culture. Whether the study is well-executed or not, I want to know what the funding mechanisms are because there is a history of commercial funders inserting themselves in various aspects of study design and reporting. I won’t discount a study solely on the basis of the outcomes’ favourability to the funder, but it’s an evaluative data point.


"A product based on their study and designed for people to use at home is expected to come onto the market this fall."

Obvious Question: Does Procter & Gamble have any involvement with this product?


They sponsored it


They'd be stupid not to!


Aromatherapy: Making Dollars out of Scents

"Aromatherapy has most of the attributes needed to thrive in the quack marketplace. As far as I know, however, its advocates are not pressing for inclusion under national health insurance. "

https://www.srmhp.org/archives/aromatherapy.html

....


methods that boost cognitive capacity that definitely work that no one is surprised by:

sleeping 8 hours a night (if you aren't someone who requires less)

eating healthy food usually involving lots of plants

aerobic exercise

meditation

removing distractions from your life

reading and learning new things

There is plenty of availability of all of these things that diligent efforts on them can pay enormous dividends and it's difficult to overdo. There isn't a need to do other things to achieve this goal unless you're sacrificing part of your likely needs...



i always knew my scratch & sniff sticker collection would one day come in handy.


I really wish I could just take these sort of results at face value the way I used to. But the replication crisis was real. It happened. No doubt its still happening. How could we ever read something like this and not just dismiss it out of hand?

226% boost in cognitive capacity? From a scent, delivered to a population which is old enough to be experiencing subtantial age-related smelling loss?

Is it just me? If so what am I missing?


Garbage science, funded by Proctor & Gamble so they can sell snake oil to worried older people. Absolutely disgusting. These "scientists" should be ashamed of themselves.


Yep! From the paper:

> Conflict of interest > > ML and MY have received travel expenses and compensation following presentations at P&G.


Doesn't matter. This is a copout for not reading the paper properly.


I doubt that because I have personally felt the physical effects of fragrances, both good and bad, and they can be very noticeable.

A 3x improvement maybe not really be all that surprising. Smell is a pretty strong sense when you're young but it doe's fade when you get older, especially after the age of 60. It may be rewiring/re-energizing neural connections that are getting rusty (so to speak).

Should be pretty easy to test on one's self but you might have to be 60+ years old to get those results.


If "fragrances" could improve older folks' cognition by 200%, it would be better than any of the $20,000/year drugs recently approved to treat Alzheimer's.


Alzheimer's is listed in the "Topics" related to that article on that web page.

An obvious next step would be a controlled test to see what happens with those folks.

Seems to me it'd be worth a shot if you were close to someone dealing with that. I can't see how it could hurt.


It's not just you. The result sounds ridiculously strong, impossibly strong.


Scent has a long history in the evolution of our memories. Remembering the smell of rotten food saved billions of lives over thousands of years.

So if there is some neurotrophic result from any increase due to scents, then whatever it is, may be good.


On the other hand, the Swedes....

https://en.wikipedia.org/wiki/Surströmming


> Remembering the smell of rotten food saved billions of lives over thousands of years.

Probably, yet somehow so many cultures still developed fermentation.


Kind of a big difference in smell. Can you really not tell the difference?


That's going to depend on what is fermented and how. E.g. malt vinegar tends to make me wonder when I showered last, and the smell of the air in newly opened yogurt has been a little off-putting ever since I had kids.


Wow, those are totally different smells to me for malt vinegar


This is kinda the point... of Sommelliers, those with exceptional olfactory +1s

I personally have a really poor sense of smell.

I can drink horrible wine, and it wont bother me... my girlfriend on the other hand was Cellar Somm at the most famous restaurant in California, and has a nose for wines that are in the out-of-reach for most people.

There is a wine maker, Mark Jessup - the winemaker for the infamous Opus One... his current winery is fantastic, his statement was that the price limit one should do for "really good drinkable wines" is ~$150 MAX. Diminishing returns after, unless you have other ties to the price of the bottle.. but a ~$90-~$150 bottle is going to give you the best dollar for decanting. (https://www.jgregorywines.com/about_us)

Else, drink what you like...

But if you look at Harlan and such (even against screaming eagle) - they are amazing, but are just in the next tier of budget (just like grinding an RPG, level up - bigger numbers, same basic relative stats.)

-

I do recommend Cadueces Maynard James of band TOOL...

Best ~$90 bottles

Always order over phone and request signed bottles by winemaker. (in general)


> a nose for wines that are in the out-of-reach for most people

A curse akin to perfect pitch. Red wine gives me a headaches and I think $10 bottles of Moscato taste wonderful.

Leaves more room in my budget for things that my palate can comprehend, which mostly derive from malted grains.


Interesting point. I guess our sense of smell coupled with memory and observation and poisoning our enemies and losing our loved ones over the eons allowed for a sophisticated pallets such as the nuances sommeliers have


> It involved men and women aged 60 to 85 without memory impairment. All were given a diffuser and seven cartridges, each containing a single and different natural oil. People in the enriched group received full-strength cartridges. Control group participants were given the oils in tiny amounts. Participants put a different cartridge into their diffuser each evening prior to going to bed, and it activated for two hours as they slept. People in the enriched group showed a 226% increase in cognitive performance compared to the control group, as measured by a word list test commonly used to evaluate memory.


I'm in the beginning of that age group so I'm gonna have to look into this.


Aside from comments claiming that the article is BS because it is funded by P&G, I can tell that aromatherapy works.

Be scientific, try it yourself.

1. Get 100% lavender oil, put a couple of drops onto your pillow before sleep. Sleep and see how rested you are.

2. Get a diffuser. Set it up drop a few drops of lavender oil in it. Let it run while you watch a movie, read news etc. Feel the relaxation and calm.

3. Drop a few drops of peppermint oil into the diffuser before you do a task that requires concentration. Feel the alertness.

I do not know about the health benefits, but essential oils work on me if I want to relax or increase my attention passively.


Someone will probably say that the (real and positive) results are due purely to the placebo effect.

I say, so what, the results are real, who cares what the mechanism of action is as long as it's harmless.


I think it's well accepted that mood / mental state can affect performance. It's also well accepted that smells can affect us emotionally. I think the burden of proof is on anybody who doesn't think smells can affect performance.

They should, ideally, have to perform this work while sitting in a smelly public bathroom.


There’s also an argument to be made that the average scientist is more anxious and in their head than the average human.

So the effect of “X thing relaxes Y person, which leads to better outcomes” is woefully understudied/underutilized, since it doesn’t work on the scientists/doctors themselves.


I think it's somewhere between real and placebo, if that makes sense. I doubt that any particular essential oils themselves actually have their own effects; rather they provide a degree of stimulation to the senses that is therapeutic.


I say HN just got gamed by low karma accounts in a coordinated way to shill essential oils.

Even the personal accounts here don't sound like 226 percent cognitive improvements mentioned in the sales piece - err I mean article.


Anecdata, I've used lavender to deal with my misophonia in the past. A few whiffs from an inhaler after a trigger noise acts like a reset button for my senses. The tension and the touch-confusion lessen pretty dramatically.


More and more people are noticing you can actually feel lavender working, and there are studies proving it.

https://pubmed.ncbi.nlm.nih.gov/17267908/ https://factor.niehs.nih.gov/2019/9/feature/3-feature-lavend...

This is a different (linked?) effect than what you were talking about but it's good evidence that some essential oils do change our bodies


I actually had a doctor recommend lavender oil capsules for treating a family member's anxiety...was rather surprised but it seems there's at least enough science behind it to persuade medical professionals.


Slate star codex recently did an article about this:

https://astralcodexten.substack.com/p/lavenders-game-silexan...


also try with a fake substance that only smell like lavender, let someone choose for you. repeat various times and when you get enough data, compare! possibly with more than 1 person.


Note that ultrasonic diffusers have some questionable health effects due to the small particles they create (other types of diffusers don’t): https://dynomight.net/humidifiers/


All true, but worth mentioning that if you used distilled water and keep the humidifier clean, all of the listed issues no longer apply. The real issue is the aerosolized minerals, not the humidifier per se.

(not trying to argue at all, just providing additional context)



And thus, the spice must flow.

When I was a child I looked forward to all the amazing medical breakthroughs that would come in my lifetime. Now all I can imagine are companies patenting them, stifling innovation and causing prices to skyrocket.

Glad this 'article' is BS.




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