I'm a little bit skeptical but i dont have any objective argument or experience in the field to justify it. I didn't want to post it, but I was surprised that almost no one in the hn comments had the same feeling.
Don't get me wrong, I would love this finding to be replicable, it would be pivotal as what other nerves could we stimulate to change perception (think pain, mental health issues, loss of senses).
Also, I wonder if this could take us closer to understand a little bit more of how the brain works. Like this could be a great way for normalizing 'inputs' and see how different brains react to it.
Very very exciting news, but I will hold on my hype until someone else can replicate this result.
>> We reliably produced distinct scents such as a campfire burn or fresh air!
These are exactly the types of smells people report when they get head CT scans (I've experienced it myself). Always thought it was ozone forming but perhaps it's more interesting than that.
It looks like independent hackers with a strong technical background and little regard for decorum.
Their methodology seems reasonable, and their results are plausible.
I’m reserved about the final part of the post where they moot about applications, but the core result seems solid. They elicited osmosphenes like one can elicit phosphènes by targeting the visual cortex.
Don't get me wrong, I would love this finding to be replicable, it would be pivotal as what other nerves could we stimulate to change perception (think pain, mental health issues, loss of senses).
There's quite a lot of research in this direction (stimulation, be it ultrasound or otherwise) to tackle exactly things you mention. Not completely sure but probably stimulators to suppress epilepsy are the most common. It has been proven in animal research stimulating the right area induces visual stimuli - IIRC this has been tested and confirmed in humans as well, i.e., make people see again. And there's more going on.
In the end: everything in the brain is electrical current. Meaning that in theory stimulating the right bits can do pretty much everything.
Chiming in as a reply to your comment since I had a similar feeling. There's no... institution!? No university or other institution listed. They list author names, which is something. But no institution, no paper, no heritage of research concepts. No citations outside of a few NIH ones not especially specific to their particular experiment. No real meaningful discussion of mechanisms. The domain itself doesn't have anything other than this page. Granted, whatever, there's no rules in this world, do what you want. But so far there's precious little in the traditional signals we typically rely on to distinguish this from misinformation.
This reminds me a bit of the escherian staircase video from 10+ years that went viral. A bunch of college students walking down the stairs, acting amazed when they found themselves back at the top. It was great acting and video editing, but it was fake and all part of, if I recall correctly, an art project.
I don't want to dismiss it outright either, seems cool as hell. But it's remarkable to me that all it takes is a blogpost to get this amount of uncritical acceptance of a demonstration.
Microorganisms, the greenhouse effect, and celestial bodies Uranus and Pluto were discovered by people without prior scientific credentials. If somebody stumbles upon an interesting observation which cannot be explained by an obvious mistake, it's worth taking and reproducing seriously.
Every raving crank tells this story to themselves about how they're the next Galileo, and that they are the exception that warrants suspending our skills for critical interrogation.
I think this is cool, plausible and warrants investigation, but not suspension of disbelief. There needs to be a better way to go about this than responding "what about Galileo!?" to any principled application of critical thinking.
Your offhand dismissal of citizen science with an anecdote about an endless stair video edit is not a well principled application of critical thinking.
One has to set prejudice to the side and examine the claim being made to apply criticl thinking.
This is a spectacular misread of my comment on practically every level. I noted the absence of numerous contextual things we typically, appropriately(!), rely on as indicators of credibility, gave an example of unsourced video illustrating what can go wrong, and emphasized that I wasn't dismissing it outright! If this is a words-mean-things conversation then those are meaningful points you haven't even pretended to address.
I agree there are some red flags here to me. One is the priority claim "As far as we know, no one seems to have done this kind of stimulation before - even in animals." The other is the definitive conclusion based on weak experimental design and documentation, "Can ultrasound make you smell things that aren’t there? Turns out, yes!"
These are big scientific claims, but the work is clearly too premature to make those conclusions, and it lacks the connection to prior work and peer review needed for making priority claims. It's really great hacker-tinkering work though, and it could turn into solid science if they take more care with it.
If this effect is real and truly novel, my cynical expectation is that someone already established in focused ultrasound will read this, apply a more rigorous approach, and get the recognition that they are hoping for through more establish channels.
I wonder where they got their equipment and research space. A charitable explanation is that they purchased it out of their own pockets, but otherwise, they really should acknowledge their support if it's from a university, federal grant, foundation award, etc. In my opinion as someone with domain experience, they don't show any novel solutions to accomplish this, it's mostly just that they have the time and resources to experiment try out, so it's especially important to acknowledge who enabled it.
One retraction, this does actually have quite rich discussion of physical mechanisms. And the point at the end about open ended signal transmission is fascinating due to limited olfactory post-processing is fascinating.
This is exceptionally cool!
It looks like this post isn’t getting much love though. I’ll see if I can get this post added to the second chance pool[1] and get it added to the front page!
All: if you seen a particularly good submission that has fallen through the cracks, please email hn@ycombinator.com so we can take a look and maybe put it in the second-chance pool (https://news.ycombinator.com/pool, explained at https://news.ycombinator.com/item?id=26998308), so it will get a random re-upment on HN's front page.
(Yes, it's permissible to request this for your own stuff, but we like it better when it's something you just ran across randomly and realized was interesting—as mmulet did in this case!)
As someone who was born without a sense of smell this is incredibly intriguing to me.
I've always wondered if there's gonna be a time in my life where I'd be able to experience *any* kind of smell through some new scientific discovery. And maybe this is it.
Could I shoot you guys a message when I make my way down to Caltech to try this out someday? :)
Out of curiosity, does lacking the sense of smell influence your sense of taste? Do some things taste wildly differently to you versus how your friends would describe them? I have a very weak sense of smell that comes and goes (sometimes I get weeks without being able to smell anything other than the strongest scents) and it definitely has an impact on my appetite and how much I enjoy certain foods. I have noticed that I'm much more sensitive to texture and mouth feel than others and I suspect it's because of this, but I also have AuDHD so I can't be sure.
I'm also a lot more sensitive about texture and mouth feel than friends and family. I know that my taste of things differs from others substantially and I cannot appreciate any nuances in food. Fine dining for example is just wasted on me.
You could for example mix a lot of cinnamon, thyme, cilantro and turmeric in my rice and I wouldn't notice any difference as I just can't taste most spices at all since they seem mostly smell based. This also makes it a lot harder for me to actually pinpoint what I like about certain dishes and dislike about others. It's just a combination of texture and the basic tastes.
I imagine someone who lost their sense of smell later in life would find the way I experience food horribly bland, but I don't! I still find great joy in food, just in a simpler way I guess.
That's why I asked about comparison with friends etc. Senses are highly subjective, hard to describe and I'm not a matter expert so I'm not hoping for a quantitative answer, but despite all this I believe there still are some learnings to be had from such discussions. HN is mainly a curiosity-driven forum - without this, we'd just complain about AI eating the world ad nauseam.
The condition is called Anosmia and can stem from different sensor and brain conditions. It would be interesting to try the technique on people with these conditions to map the different kinds of olfactory failures.
If you get in contact with the researchers, please let us know how it went.
Please include me also in contacts. I developed anosmia about 8 years ago (well before COVID). I truly wish there were some sort of 'cure' that would restore even a small amount of my sense of smell.
Since you never had any sense of smell, would this help you in developing memories about smell ? I am curious on how your brain react to smell sensation when it does not have any memory associated with it.
That's also something I think about when imagining smelling for the first time.
E.g. smelling something rancid for the first time - how strong of a negative reaction will it be compared to others who grew up with this negative association.
Would I ever even be able to map most of the smells others have memorized to their origin?
I really hope I get to find out someday.
Smells really get embedded into your conscience from early days. I remember as a kid really loving the "Smell-O-Vision" movie they had set up at La Cité des Sciences et de l’Industrie in Paris. As you watched they had little aerosol cans labeled with different scents ("baking bread" etc) that a mechanism would squirt towards the viewer.
I found this History of Smell-O-Vision paper too today:
I'd maybe make a hypothesis that a large portion of the space is "bad" smelling stuff: smoke or garbage. When people had covid-induced parosmia, it almost always seemed to be bad smelling stuff.
Still have it, intermittently. A sort of nameless-but-familiar "chemical" smell that comes and goes, along with any sense of taste. That is, I have bad days with no taste, just a chemical smell. Other days I have a pretty good sense of smell, generally with a good sense of taste.
Intriguingly some of the really unpleasant smells never get through to me - I could probably work at a sewage works now. Worryingly I have next to no ability to smell burning, though I do now get the smell of natural gas (or the additive used to make it smell).
There has been promising work on olfactory training, which you can do very inexpensively at home. If you can, I would consider seeing any ENT first to rule out polyps, etc.
This is something I'm still testing, so take it with a bucket of salt, but I've found that exposing myself to very strong samples of things that I was unable to smell made something click again and I started to smell them again. Seems like something in there needs to be retrained to odors.
That's the basic method of retraining. I've got a bunch of essential oils in tiny jars and I regularly take a 20 second sniff of each whilst thinking strongly about the smell in context. For example, when I smell the lavender oil I recall the garden at my grandma's house which obviously was full of lavender. It's definitely helping, but there are still a lot of gaps.
I'm convinced that over the decades we'll continue to be a little surprised but just how much of our body-machinery is doing jobs of self-calibration, regulation, and safety-interlocks.
That was exactly my thought when reading the article and my personal experience with Covid. For a couple weeks, I perceived a persistent smell of something burning.
A smell of burning was how I suspected I had COVID the last time around. I was around some machines, I had to have someone else sniff around and let me know that nothing was actually burning.
Same here, and it's still there. I can't smell or taste a random set of stuff, like cinnamon, poop/farts. What annoys me most is that female genitalia just taste like nothing, literally...
In addition to this, I sometimes smell scents that do not exist.
Super interesting! That would make sense, because a lot of the nose is presumably dedicated to smelling evolutionarily-relevant smells, most of which are "smells bad, avoid this". The method is very crude right now, but maybe with more fine-grained targetting we could better tune the smell profile.
And even good / bad is sometimes subjective and brain can adjust to it depend on whatever you like the taste for instance. Tell you this as a big fan of durian. Since there a lot of chemicals responsible for smell brain override reaction to fruit once you love the taste.
I wonder if we search for the worst smell, via optimization, is does this make it a big, not very steep optimum? Or maybe all unknown smells are a little bad, but the worst smell is some familiar badness.
Reminiscent of a finding reported at a neurology conference in the 1960s that served as the epigraph to J.H. Prynne’s collection of poems Wound Response:
“Of particular interest in the present context are the observations made on patients whose middle ear had been opened in such a way that a cotton electrode soaked in normal saline solution could be placed near the cochlea. A total of 20 surgically operated ears were studied. Eleven patients heard pure tones whose pitch corresponded to the frequency of the sinusoidal voltage applied to the electrode… One patient reported gustatory sensations.”
Certainly! We didn't get a chance to test it on more people before we had to take it apart, but we thought the result was too cool to share. Would love to see other folks run with the idea!
It’s just a blog post. No academic is going to read it as more than a very promising early result.
The issue is that lay people read every paper or post as if it were a final proclamation. They’re not. Even a peer reviewed paper on the cover of Science or Nature is still not “proof” of anything, science doesn’t produce positive confirmation. It produces evidence that taken together suggest one prior is more likely than another.
Bayes Rule is very intuitive. We update the prior by the likelihood of the evidence under a given prior divided by the likelihood of the evidence. That’s all it is.
Unfortunately, there is a very strong motive to flag plant. Academia is a water full of sharks.
Oh god, do we really want to have the smells of sex when watching porn?
On the other hand, I see an opportunity even without tech: porn star perfume collabs: Spray some Gukki Bloom and press play on that video to smell what the star was wearing on the day.
But I guess high-end perfume brands don't want to be associated with actors of the flesh.
You're getting downvoted, likely for prudish reasons, but in all seriousness it doesn't seem unlikely that you're right.
The porn industry has historically been very quick to adopt new technologies, it's easy to see how this could benefit that industry, so it's a logical enough conclusion to draw. They'll very likely be the first commercial application of this, once viable.
The scene from Torrente comes to mind where the protagonist gives a set of anal beads to a gay guy who then identifies it as ar*e smell, hence it was used. Or smth like that :D.
reminds me of the book "ready player one" in which world-builders would insert terrible smells to troll the minority of VR players with a smell-o-vision device
Woah I didn't know about that theory, that's really interesting! If I understand correctly, it's that the ligand needs to both fit "physically" and also have the right vibrational mode to have high binding affinity / trigger the receptor? Sounds like the relevant frequencies would be in IR range, or roughly 10-100 terahertz. We're at 300 kHz, so 9 orders of magnitude lower, so we're likely not activating the receptors directly with that mechanism. But, maybe the acoustic radiation force from the ultrasound gives existing molecules in the air enough energy to increase the coupling? And nobody seems to really know how ultrasound neurostimulation really works, so who knows—maybe something similar even happens with neurotransmitters in cortex...
Well, if it’s waves, perhaps principles of consonance and dissonance might apply.
Robert Hooke thought so…
“Now as we find that musical strings will be moved by Unisons and Eighths, and other harmonious chords, though not in the same degree; so do I suppose that the particles of matter will be moved principally by such motions as are Unisons, as I may call them, or of equal Velocity with their motions, and by other har∣monious motions in a less degree.
I do further suppose, A subtil matter that incom∣passeth and pervades all other bodies, which is the Menstruum in which they swim which maintains and continues all such bodies in their motion, and which is the medium that conveys all Homogenious or Har∣monical motions from body to body.
Further I suppose, that all such particles of matter as are of a like nature, when not separated by others of a differing nature will remain together, and strengthen the common Vibration of them all against the differing Vibrations of the ambient bodies.
According to this Notion I suppose the whole Universe and all the particles thereof to be in a con∣tinued motion, and every one to take its share of space or room in the same, according to the bulk of its body, or according to the particular power it hath to receive, and continue this or that peculiar motion.
Two or more of these particles joyned immediately together, and coalescing into one become of another nature, and receptive of another degree of motion and Vibration, and make a compounded particle differing in nature from each of the other par∣ticles.
All bulky and sensible bodies whatsoever I suppose to be made up or composed of such particles which have their peculiar and appropriate motions which are kept together by the differing or dissonant Vibrations of the ambient bodies or fluid“
You write that "The olfactory bulb can vary in size by up to 3x, depending on "age and olfactory experience", so perhaps (we're making this up) with more usage your olfactory bulb might actually get bigger" which certainly does not seem out of the question. What we can assume with even greater likelihood is that the sense of smell works better when regularly stimulated. Even if your method did not have any commercial applications in entertainment it could likely (at least if this method scales beyond 4 distinct sensations) have therapeutic potential for people who suffer from blocked noses, chronic sinusitis, allergies or other conditions that block their sense of smell for physical reasons. It might even be used by Sommeliers to retain the capacity for their tradecraft while unable to use their actual nose while suffering from a cold. As we know that there is a strong association between smell and memory there are many other useful therapeutic and educational applications that come to mind if this technology can be made safe for broader consumer use. Right now, regardless of protocols used, you are somewhere on the spectrum between shining nascent lasers at your eyes to determine whether they work and emit light output (which doesn't scale with an increase in power) and the nobel prize worthy quadrant of Jonas Salk and Barry Marshall. While I do hope you succeed and I'd hate for you to be overly cautious I also hope your (olfactory) neurons survive!
I had the same thought - I guess it's similar to that idea that if you had someone else's eyes, you might not perceive specific colours to be the same?
But actually it sort of makes sense since (from what I understand) is stimulating an external interface (the receptors), so you're mimicing what the effect a smell would have on you rather than the electrical signal created by the response to a stimulus?
Sorry it's unclear in the post, they weren't exactly the same! The numbers reported were on Lev, and we swept them around that range for me (Albert). But we didn't take down the exact values, so unfortunately I don't know how similar the maps were. iirc they were pretty different.
Interesting that burning was one of the smells. AFAIK that often comes up in neurological problems like strokes and epilepsy, so is it a particularly coarse sensation (like exciting all the different specialised neuerons at once)?. I imagine there's going to be a long challenge of targeting this to elicit more refined scents.
Me wonders if this can be applied to other parts of the brain, perhaps recalling long buried memories? In my case, "a 12‑lexeme mnemonic constellation that operates as a cognitive entropy incantation, each syllabic particle mapping onto a quantized shard of an authorization singularity’s randomness reservoir. This ordered cascade of linguistic quanta serves as a deterministic bootstrap constant, re‑materializing access to a distributed transactional continuum avatar via recursive derivation algorithms. In practice, it’s a compact neuro‑linguistic checksum spell, a bridge where human cortex patterns resonate with machine‑level information‑integrity archetypes, conjuring identity from chaos like a linguistic particle accelerator, aka ₿" ;)
"Which it be, ye scallywag, but nay—mark me well—’tis no tavern’s tall tale. Nay, ’tis truth carved in bone and blood, a story black as the Devil’s beard, yet truthful enough to make Death himself chuckle in his coffin."
(╯︵╰,)
/ \
₿
Haha, luckily not! It's a very speculative link, so we didn't want to talk about "AI" too much in the main post. But we originally got interested in this concept because we are interested in other forms of input to the brain (other than the classic reading, listening, watching, etc). The nose is interesting because it seems to have many independent basis vectors and very sharp discrimination ability, so it might be a sensor into which you can pack many inputs. LLMs are just a proof-by-example that ~1k input dimensions is enough to really encode semantic meaning.
I'd personally be very sceptical that the human brain could derive much meaning from smell beyond "smells bad don't eat" or "reminds me of something", but I guess I would have said the same about creating smells via ultrasound so what do I know.
Woah, that would be wild! It seems like most neonatal ultrasound reaches peak internal pressures of few-hundred kPa to 2 MPa. We ranged from 150-250 kPa. So, a little lower than the lower end of prenatal diagnostic imaging.
So, the pressures are high enough to be stimulating them! But most diagnostic imaging happens at 1-20 MHz, while most neurostimulation seems to occur at few-hundred kHz (we were at 300 kHz, on the mid-high end). So I don't think it's likely that babies are being sent smells?
That's a really interesting concept! The wiki page right now ends in "example of a combination of smells that neutralise each other", which makes me wonder if the "olfactory white" combinations are actually tuned to neutralize? I suspect what we're hitting is a bunch of receptors, and the brain is interpretting it as a common strong and evolutionarily important smell (which I assume has stronger pathways by default).
I was an organic chemist, and as such worked I've worked in various "wet" laboratories. All of them had store rooms and cabinets with hundreds or thousands of bottles filled with horribly smelling goop. Besides the occasional terpenoid (naturally occurring things smelling like menthol, cloves or cinnamon) nearly everything there was liquid death.
These smells have everything: Harsh solvent-like stuff like strong alcohol or glue, rotten fish amines, off-sweet halocarbons, things like burnt plastics, excrement, or stuff that defies description as to their lingeringly terrible sensation of olfactory wrongness (selenium compounds).
There is actually a thing called "cadaverine", that should tell you enough.
Still, every sufficiently large storage space I rememebet had this identical, not unpleasant, thickly sweet, but not easily defined smell.
So to conclude, I think it's a brain glitch when we input everything, all the smells, at the same time.
I could have sworn that sickly sweet smell was the smell of various phosphine reagents? Just my vague recollection of my time in lab from 15 years ago.
Phosphines, for me, were either odorless (for heavy ligand like things like triphenylphosphine) or absolutely rancid fishy mixed with a burnt chemical note. thankfully I never inhaled too many of the light organophosphines, they aren't too healthy...
Finally a solution to long term nuclear warning messages! [1] All we have to do is merely create an ultrasound emitter that works over a distance of meters and lasts several thousand years. Then assail our post apocalyptic adventurers with a stench so vivid it elicits ancient racial memories of global thermonuclear war.
Given that people can remember smell for years, this might be very useful for learning aid. Hook it up to an IDE and let people literally smell bad code as garbage.
Totally! We think this is because the brain is hard-wired evolutionarily to interpret smells by danger level first. So maybe there's just more "bad smell" receptors, or maybe the brain treats unknown smells as "uh oh, danger". Lots of cool stuff to test!
I'm intrigued by the neuromodulation possibilities of this method, but I don't really understand how far can that ideally go. Since the authors are here, can you go a bit deeper in this? Thanks!
This would be very cool within a game setting. Just imagine feeling the sensation of fresh air as you go through a door. Even if it were small effects it could add a huge leap in realism and immersion. Smell is a very powerful sense.
I cant wait for the day when the perfume and food shops in the mall use this for truly targeted advertisement. Cue rise of ultrasound-proof hats and lawsuits by people who report feeling sick due to such ads.
The adult videos industry must be already closely looking at this, and I wouldn't be surprised if they don't finance related research soon in the future, it will be VHS vs betamax all over again.
Yes, to simulate pheromones and related stimulus, that too, but I'm sorry if you already don't know this but a faint smell of urine would be a big deal to a non-trivial amount of men for immersion, without going into too much detail "squirting" fans and all the ecosystem around such kind of fetishes.
The natural progression of this technology is probably miniaturized transducer arrays on a chip, which would enable non-invasive write access to the entire brain.
This kind of tech should be developed as open-source projects, even for the firmware and hardware. A sufficiently advanced version of this, if widely deployed as proprietary blackboxes like smartphones are, would allow one consciousness to take over multiple bodies without their original owners knowing.
If they’re using enough ultrasound energy to create a physical reaction inside the subjects head strong enough to smell like a burning camp fire, I can’t imagine they’d survive long enough to report it. Maybe I’m misunderstanding your implication?
maybe the ionized oxygen sensation, the ozone, the garbage and smoke are like a thin film of garbage and smoke particles in the nasal cavity experiencing mechanical stimulation. the mr guidance seems like a good idea, but the actual mount and targeting sounds crude, what are the odds it's just in the nasal cavity warming up and activating the gross stuff that lives in there?
i wonder if some kind of inhalable anesthetic would be a good control. ie, if the normal sensory pathways are blocked and the lifu stim of the olfactory bulb still creates the percept, then maybe it would be evidence that it is working as it appears...
My prediction is that in the not-to-distant future, we’re all going to live indefinitely in simulations that optimized for human experience. To do this, AIs will “highjack” our nervous systems and feed generated worlds to use to experience. This kind of thing makes it seem like it’s pretty realistic.
> The scans are painless, have no known side effects on mothers or babies, and can be carried out at any stage of pregnancy.
If you read the linked article, you'd see that most of it focused on how extremely hard it was to get the ultrasound to do anything - it required an MRI and exact positioning of the ultrasound transducer. I doubt that 5 minutes of being gently prodded through the skin and fat is going to harm a child. Also, ultrasounds (and waves and radiation of all sorts) are passing into your body at all times, so it's not like they are exposing the fetus to something rare or unusual.
The NHS are less strident about this these days (I haven't checked since my sons were born - they used to dissuade 5d scans entirely), but this guide gives a flavour of the caution they invoke around private scans:
This is absolutely my question as well - curious if it's legal to do this, I'm guessing yes as it's an existing ultrasound device? But is there possibility of permanent damage?
It's objectively cool, but very curious about the safety as well.
This is the coolest part! Turns out, the powers you need are actually lower than what is used for imaging babies :) We measured our probe with a hydrophone on a computer-controlled scanner to get the pressure field, and made sure that it's below diagnostic levels (the generally accepted mechanical index limit is 1.9 and ours was 0.4 peak). We also made sure to avoid the eyes and keep thermals in check.
That's reassuring, but not entirely reassuring. Fetuses are a bit further from the emitter. You're focusing the pressure waves, but what about peripheral pressure waves disrupting the brain?
What would make it illegal to do this? Generally anything which hasn't been invented yet is legal, it's rare (but not impossible) for something to be banned before it exists.
9. Does FDA require IRB review and approval of off-label use of a legally marketed device?
...(unrelated for this conversation)...
Yes, when the off-label use of a legally marketed device is part of a research study collecting safety and effectiveness data involving human subjects, IRB review and approval is required (21 CFR 812.2(a)). For additional information on the off-label use of devices, see the FDA Information Sheet guidance, “ ‘Off-label’ and Investigational Use of Marketed Drugs, Biologics and Medical Devices.”
OK, I want to meet these guys. This writeup has several breathtaking (if you will) passages. Like:
> "We found different scents by steering the beam over ~14 mm (20 degrees at 4 cm radius). The distance between freshness and burning was ~3.5 mm."
> "The olfactory system potentially allows writing up to 400, if not 800 due to two nostrils, dimensions into the brain. That is comparable to the dimensionality of latent spaces of LLMs, which implies you could reasonably encode the meaning of a paragraph into a 400-dimensional vector. If you had a device which allows for this kind of writing, you could learn to associate the input patterns with their corresponding meanings. After that, you could directly smell the latent space."
This just makes me grin with total delight. Completely freaking fascinating.
> The olfactory system potentially allows writing up to 400, if not 800 due to two nostrils, dimensions into the brain. That is comparable to the dimensionality of latent spaces of LLMs, which implies you could reasonably encode the meaning of a paragraph into a 400-dimensional vector. If you had a device which allows for this kind of writing, you could learn to associate the input patterns with their corresponding meanings. After that, you could directly smell the latent space. A bit of ultrasound, a breath in - and you understood a paragraph.
Translation: We’re very concerned that the only projects getting funding right now have to use AI.
I'm a little bit skeptical but i dont have any objective argument or experience in the field to justify it. I didn't want to post it, but I was surprised that almost no one in the hn comments had the same feeling.
Don't get me wrong, I would love this finding to be replicable, it would be pivotal as what other nerves could we stimulate to change perception (think pain, mental health issues, loss of senses).
Also, I wonder if this could take us closer to understand a little bit more of how the brain works. Like this could be a great way for normalizing 'inputs' and see how different brains react to it.
Very very exciting news, but I will hold on my hype until someone else can replicate this result.
>> We reliably produced distinct scents such as a campfire burn or fresh air!
These are exactly the types of smells people report when they get head CT scans (I've experienced it myself). Always thought it was ozone forming but perhaps it's more interesting than that.
I believe that ozone is usually reported as smelling like pansies (the flowers).
This is TFUS [1] with a novel target.
It looks like independent hackers with a strong technical background and little regard for decorum.
Their methodology seems reasonable, and their results are plausible.
I’m reserved about the final part of the post where they moot about applications, but the core result seems solid. They elicited osmosphenes like one can elicit phosphènes by targeting the visual cortex.
1. https://en.wikipedia.org/wiki/Transcranial_focused_ultrasoun...
Don't get me wrong, I would love this finding to be replicable, it would be pivotal as what other nerves could we stimulate to change perception (think pain, mental health issues, loss of senses).
There's quite a lot of research in this direction (stimulation, be it ultrasound or otherwise) to tackle exactly things you mention. Not completely sure but probably stimulators to suppress epilepsy are the most common. It has been proven in animal research stimulating the right area induces visual stimuli - IIRC this has been tested and confirmed in humans as well, i.e., make people see again. And there's more going on.
In the end: everything in the brain is electrical current. Meaning that in theory stimulating the right bits can do pretty much everything.
Chiming in as a reply to your comment since I had a similar feeling. There's no... institution!? No university or other institution listed. They list author names, which is something. But no institution, no paper, no heritage of research concepts. No citations outside of a few NIH ones not especially specific to their particular experiment. No real meaningful discussion of mechanisms. The domain itself doesn't have anything other than this page. Granted, whatever, there's no rules in this world, do what you want. But so far there's precious little in the traditional signals we typically rely on to distinguish this from misinformation.
This reminds me a bit of the escherian staircase video from 10+ years that went viral. A bunch of college students walking down the stairs, acting amazed when they found themselves back at the top. It was great acting and video editing, but it was fake and all part of, if I recall correctly, an art project.
I don't want to dismiss it outright either, seems cool as hell. But it's remarkable to me that all it takes is a blogpost to get this amount of uncritical acceptance of a demonstration.
Microorganisms, the greenhouse effect, and celestial bodies Uranus and Pluto were discovered by people without prior scientific credentials. If somebody stumbles upon an interesting observation which cannot be explained by an obvious mistake, it's worth taking and reproducing seriously.
Every raving crank tells this story to themselves about how they're the next Galileo, and that they are the exception that warrants suspending our skills for critical interrogation.
I think this is cool, plausible and warrants investigation, but not suspension of disbelief. There needs to be a better way to go about this than responding "what about Galileo!?" to any principled application of critical thinking.
Your offhand dismissal of citizen science with an anecdote about an endless stair video edit is not a well principled application of critical thinking.
One has to set prejudice to the side and examine the claim being made to apply criticl thinking.
This is a spectacular misread of my comment on practically every level. I noted the absence of numerous contextual things we typically, appropriately(!), rely on as indicators of credibility, gave an example of unsourced video illustrating what can go wrong, and emphasized that I wasn't dismissing it outright! If this is a words-mean-things conversation then those are meaningful points you haven't even pretended to address.
I agree there are some red flags here to me. One is the priority claim "As far as we know, no one seems to have done this kind of stimulation before - even in animals." The other is the definitive conclusion based on weak experimental design and documentation, "Can ultrasound make you smell things that aren’t there? Turns out, yes!"
These are big scientific claims, but the work is clearly too premature to make those conclusions, and it lacks the connection to prior work and peer review needed for making priority claims. It's really great hacker-tinkering work though, and it could turn into solid science if they take more care with it.
If this effect is real and truly novel, my cynical expectation is that someone already established in focused ultrasound will read this, apply a more rigorous approach, and get the recognition that they are hoping for through more establish channels.
I wonder where they got their equipment and research space. A charitable explanation is that they purchased it out of their own pockets, but otherwise, they really should acknowledge their support if it's from a university, federal grant, foundation award, etc. In my opinion as someone with domain experience, they don't show any novel solutions to accomplish this, it's mostly just that they have the time and resources to experiment try out, so it's especially important to acknowledge who enabled it.
One retraction, this does actually have quite rich discussion of physical mechanisms. And the point at the end about open ended signal transmission is fascinating due to limited olfactory post-processing is fascinating.
Ad verecundiam. One does not need to be in a institution to come up with interesting observations/ results.
To be frank the reason that make me question it the most is how repetitive the redaction is. Seems LLM-like.
However, that's not a valid reason to discard an interesting result.
[dead]
This is exceptionally cool! It looks like this post isn’t getting much love though. I’ll see if I can get this post added to the second chance pool[1] and get it added to the front page!
[1]https://news.ycombinator.com/item?id=26998308
Added! Thanks for requesting this.
All: if you seen a particularly good submission that has fallen through the cracks, please email hn@ycombinator.com so we can take a look and maybe put it in the second-chance pool (https://news.ycombinator.com/pool, explained at https://news.ycombinator.com/item?id=26998308), so it will get a random re-upment on HN's front page.
(Yes, it's permissible to request this for your own stuff, but we like it better when it's something you just ran across randomly and realized was interesting—as mmulet did in this case!)
Wow good to know, thank you guys!
As someone who was born without a sense of smell this is incredibly intriguing to me. I've always wondered if there's gonna be a time in my life where I'd be able to experience *any* kind of smell through some new scientific discovery. And maybe this is it.
Could I shoot you guys a message when I make my way down to Caltech to try this out someday? :)
Out of curiosity, does lacking the sense of smell influence your sense of taste? Do some things taste wildly differently to you versus how your friends would describe them? I have a very weak sense of smell that comes and goes (sometimes I get weeks without being able to smell anything other than the strongest scents) and it definitely has an impact on my appetite and how much I enjoy certain foods. I have noticed that I'm much more sensitive to texture and mouth feel than others and I suspect it's because of this, but I also have AuDHD so I can't be sure.
I'm also a lot more sensitive about texture and mouth feel than friends and family. I know that my taste of things differs from others substantially and I cannot appreciate any nuances in food. Fine dining for example is just wasted on me. You could for example mix a lot of cinnamon, thyme, cilantro and turmeric in my rice and I wouldn't notice any difference as I just can't taste most spices at all since they seem mostly smell based. This also makes it a lot harder for me to actually pinpoint what I like about certain dishes and dislike about others. It's just a combination of texture and the basic tastes. I imagine someone who lost their sense of smell later in life would find the way I experience food horribly bland, but I don't! I still find great joy in food, just in a simpler way I guess.
Genuine question: how would they know if it has always been a certain way?
If they _lost_ their sense of smell, they had something to compare it with.
That's why I asked about comparison with friends etc. Senses are highly subjective, hard to describe and I'm not a matter expert so I'm not hoping for a quantitative answer, but despite all this I believe there still are some learnings to be had from such discussions. HN is mainly a curiosity-driven forum - without this, we'd just complain about AI eating the world ad nauseam.
The condition is called Anosmia and can stem from different sensor and brain conditions. It would be interesting to try the technique on people with these conditions to map the different kinds of olfactory failures.
If you get in contact with the researchers, please let us know how it went.
Please include me also in contacts. I developed anosmia about 8 years ago (well before COVID). I truly wish there were some sort of 'cure' that would restore even a small amount of my sense of smell.
Since you never had any sense of smell, would this help you in developing memories about smell ? I am curious on how your brain react to smell sensation when it does not have any memory associated with it.
That's also something I think about when imagining smelling for the first time.
E.g. smelling something rancid for the first time - how strong of a negative reaction will it be compared to others who grew up with this negative association. Would I ever even be able to map most of the smells others have memorized to their origin? I really hope I get to find out someday.
Finally some progress towards smellovision.
Not joking, my mom has asked me every year since I became a "tech person" when I am going to make smellovision. This is perfect for her.
She should be careful what she wishes for.
All those blocked sewerage plumbing videos are going to have another subscription tier
You'll have to pay extra to turn it off.
Smells really get embedded into your conscience from early days. I remember as a kid really loving the "Smell-O-Vision" movie they had set up at La Cité des Sciences et de l’Industrie in Paris. As you watched they had little aerosol cans labeled with different scents ("baking bread" etc) that a mechanism would squirt towards the viewer.
I found this History of Smell-O-Vision paper too today:
https://pmc.ncbi.nlm.nih.gov/articles/PMC7691926/
Apple has been waiting for the opportunity to use their next moniker - iNose.
You can Apple Pay through the Apple Nose
Don't do it too much though, otherwise you're gonna need the Apple Noose, designed in collaboration with Coco Chanel.
Soon to be followed by Google Knows
iNose what you did there.
iNose iSmell, iBath
Kicks all these fart apps to a new dimension
https://youtu.be/1zp3b6YCXqI
The smelloscope, right ?
A Brief History of Smell-O-Vision
https://www.wired.com/2006/12/a-brief-history-2-2/
https://futurama.fandom.com/wiki/Smell-O-Scope
I am still waiting for the Smell Blaster.
Imagine the viruses and pranks.
Kickstarter incoming for a device that induces code smells in sync with review.
If we have negative code smells can we also make good code smell like cherry blossoms?
Vibe coding is so over
Imagine how big of a stink the linter would put up as you worked on your most recent codebase!
I'd maybe make a hypothesis that a large portion of the space is "bad" smelling stuff: smoke or garbage. When people had covid-induced parosmia, it almost always seemed to be bad smelling stuff.
I know someone whose sense of taste was ruined by a small stroke. He said basically everything tastes like old gym socks now. That would suck so bad.
Still have it, intermittently. A sort of nameless-but-familiar "chemical" smell that comes and goes, along with any sense of taste. That is, I have bad days with no taste, just a chemical smell. Other days I have a pretty good sense of smell, generally with a good sense of taste.
Intriguingly some of the really unpleasant smells never get through to me - I could probably work at a sewage works now. Worryingly I have next to no ability to smell burning, though I do now get the smell of natural gas (or the additive used to make it smell).
There has been promising work on olfactory training, which you can do very inexpensively at home. If you can, I would consider seeing any ENT first to rule out polyps, etc.
Thanks for the info. I'm on top of it (in the ways you described) but still appreciate it and maybe someone else will see your comment.
Good luck!
This is something I'm still testing, so take it with a bucket of salt, but I've found that exposing myself to very strong samples of things that I was unable to smell made something click again and I started to smell them again. Seems like something in there needs to be retrained to odors.
That's the basic method of retraining. I've got a bunch of essential oils in tiny jars and I regularly take a 20 second sniff of each whilst thinking strongly about the smell in context. For example, when I smell the lavender oil I recall the garden at my grandma's house which obviously was full of lavender. It's definitely helping, but there are still a lot of gaps.
I'm convinced that over the decades we'll continue to be a little surprised but just how much of our body-machinery is doing jobs of self-calibration, regulation, and safety-interlocks.
That was exactly my thought when reading the article and my personal experience with Covid. For a couple weeks, I perceived a persistent smell of something burning.
A smell of burning was how I suspected I had COVID the last time around. I was around some machines, I had to have someone else sniff around and let me know that nothing was actually burning.
Same here, and it's still there. I can't smell or taste a random set of stuff, like cinnamon, poop/farts. What annoys me most is that female genitalia just taste like nothing, literally...
In addition to this, I sometimes smell scents that do not exist.
Super interesting! That would make sense, because a lot of the nose is presumably dedicated to smelling evolutionarily-relevant smells, most of which are "smells bad, avoid this". The method is very crude right now, but maybe with more fine-grained targetting we could better tune the smell profile.
Good / bad / unclassified.
It makes sense for unclassified to smell worse than good, and it'd probably be the biggest category by a long stretch.
(Pure speculation.)
And even good / bad is sometimes subjective and brain can adjust to it depend on whatever you like the taste for instance. Tell you this as a big fan of durian. Since there a lot of chemicals responsible for smell brain override reaction to fruit once you love the taste.
I wonder if we search for the worst smell, via optimization, is does this make it a big, not very steep optimum? Or maybe all unknown smells are a little bad, but the worst smell is some familiar badness.
Reminiscent of a finding reported at a neurology conference in the 1960s that served as the epigraph to J.H. Prynne’s collection of poems Wound Response:
“Of particular interest in the present context are the observations made on patients whose middle ear had been opened in such a way that a cotton electrode soaked in normal saline solution could be placed near the cochlea. A total of 20 surgically operated ears were studied. Eleven patients heard pure tones whose pitch corresponded to the frequency of the sinusoidal voltage applied to the electrode… One patient reported gustatory sensations.”
Can't wait to use the term gustatory sensation to describe a meal, might save that one for Christmas dinner!
> Different focal spots corresponded to different smells, which we’ve replicated first-try on two people and validated with a blind trial.
So, N=2 and the people in question are co-authors. I'm not in this business, but isn't this too... early to publish?
Certainly! We didn't get a chance to test it on more people before we had to take it apart, but we thought the result was too cool to share. Would love to see other folks run with the idea!
It’s just a blog post. No academic is going to read it as more than a very promising early result.
The issue is that lay people read every paper or post as if it were a final proclamation. They’re not. Even a peer reviewed paper on the cover of Science or Nature is still not “proof” of anything, science doesn’t produce positive confirmation. It produces evidence that taken together suggest one prior is more likely than another.
Bayes Rule is very intuitive. We update the prior by the likelihood of the evidence under a given prior divided by the likelihood of the evidence. That’s all it is.
Unfortunately, there is a very strong motive to flag plant. Academia is a water full of sharks.
I predict a future where once again porn is the cutting edge with a cutting edge technology.
porn + vr + smell
Oh god, do we really want to have the smells of sex when watching porn?
On the other hand, I see an opportunity even without tech: porn star perfume collabs: Spray some Gukki Bloom and press play on that video to smell what the star was wearing on the day.
But I guess high-end perfume brands don't want to be associated with actors of the flesh.
No, you want the smell of your ideal partner.
You're getting downvoted, likely for prudish reasons, but in all seriousness it doesn't seem unlikely that you're right.
The porn industry has historically been very quick to adopt new technologies, it's easy to see how this could benefit that industry, so it's a logical enough conclusion to draw. They'll very likely be the first commercial application of this, once viable.
I assume the reasons are more visceral than prudish. I don't think I would want to know what a porno set would smell like.
This is coming from a place of physical discontent, not moral discontent.
It doesnt have to smell like the porno set. They could choose any smell that stimulates arousal.
For some reason this sent my train of thought towards the "people who think their shit doesn't stink" expression.
Is it still shitposting if it actually smells nice?
My brain went the down the same path. For some reason I imagined posting a YouTube clip of me farting, along with a nice scent of rose petals.
I don't think I'm ready for this technology
Movies don't sound like their sets during filming either.
The scene from Torrente comes to mind where the protagonist gives a set of anal beads to a gay guy who then identifies it as ar*e smell, hence it was used. Or smth like that :D.
I wouldn’t put too much stock in fake Internet points.
Prediction: Pi-hole gets a double entendre and becomes more useful than ever.
reminds me of the book "ready player one" in which world-builders would insert terrible smells to troll the minority of VR players with a smell-o-vision device
But will the smell be in 3D?
Just light a candle.
[flagged]
You made this account to reply to my joke comment? Haha weird
Reminds me of the vibration theory of olfaction.
https://en.wikipedia.org/wiki/Vibration_theory_of_olfaction
Woah I didn't know about that theory, that's really interesting! If I understand correctly, it's that the ligand needs to both fit "physically" and also have the right vibrational mode to have high binding affinity / trigger the receptor? Sounds like the relevant frequencies would be in IR range, or roughly 10-100 terahertz. We're at 300 kHz, so 9 orders of magnitude lower, so we're likely not activating the receptors directly with that mechanism. But, maybe the acoustic radiation force from the ultrasound gives existing molecules in the air enough energy to increase the coupling? And nobody seems to really know how ultrasound neurostimulation really works, so who knows—maybe something similar even happens with neurotransmitters in cortex...
Does everything come down to waves or to bits?
Well, if it’s waves, perhaps principles of consonance and dissonance might apply.
Robert Hooke thought so…
“Now as we find that musical strings will be moved by Unisons and Eighths, and other harmonious chords, though not in the same degree; so do I suppose that the particles of matter will be moved principally by such motions as are Unisons, as I may call them, or of equal Velocity with their motions, and by other har∣monious motions in a less degree.
I do further suppose, A subtil matter that incom∣passeth and pervades all other bodies, which is the Menstruum in which they swim which maintains and continues all such bodies in their motion, and which is the medium that conveys all Homogenious or Har∣monical motions from body to body.
Further I suppose, that all such particles of matter as are of a like nature, when not separated by others of a differing nature will remain together, and strengthen the common Vibration of them all against the differing Vibrations of the ambient bodies.
According to this Notion I suppose the whole Universe and all the particles thereof to be in a con∣tinued motion, and every one to take its share of space or room in the same, according to the bulk of its body, or according to the particular power it hath to receive, and continue this or that peculiar motion.
Two or more of these particles joyned immediately together, and coalescing into one become of another nature, and receptive of another degree of motion and Vibration, and make a compounded particle differing in nature from each of the other par∣ticles.
All bulky and sensible bodies whatsoever I suppose to be made up or composed of such particles which have their peculiar and appropriate motions which are kept together by the differing or dissonant Vibrations of the ambient bodies or fluid“
Page 9: https://quod.lib.umich.edu/e/eebo/A44322.0001.001/1:3?rgn=di...
Reminds me of the vibration theory of simulated chemicals. 3 Fisted Tales of Bob. They used sound to keep gunpowder from exploding or something.
The year is 2032. My smart fridge started A/B testing scents to reduce snacking. I ate a carrot and felt promoted.
You write that "The olfactory bulb can vary in size by up to 3x, depending on "age and olfactory experience", so perhaps (we're making this up) with more usage your olfactory bulb might actually get bigger" which certainly does not seem out of the question. What we can assume with even greater likelihood is that the sense of smell works better when regularly stimulated. Even if your method did not have any commercial applications in entertainment it could likely (at least if this method scales beyond 4 distinct sensations) have therapeutic potential for people who suffer from blocked noses, chronic sinusitis, allergies or other conditions that block their sense of smell for physical reasons. It might even be used by Sommeliers to retain the capacity for their tradecraft while unable to use their actual nose while suffering from a cold. As we know that there is a strong association between smell and memory there are many other useful therapeutic and educational applications that come to mind if this technology can be made safe for broader consumer use. Right now, regardless of protocols used, you are somewhere on the spectrum between shining nascent lasers at your eyes to determine whether they work and emit light output (which doesn't scale with an increase in power) and the nobel prize worthy quadrant of Jonas Salk and Barry Marshall. While I do hope you succeed and I'd hate for you to be overly cautious I also hope your (olfactory) neurons survive!
I find it incredible that the same olfactory activation patterns mapped to the the SAME smells in both subjects.
I had the same thought - I guess it's similar to that idea that if you had someone else's eyes, you might not perceive specific colours to be the same?
But actually it sort of makes sense since (from what I understand) is stimulating an external interface (the receptors), so you're mimicing what the effect a smell would have on you rather than the electrical signal created by the response to a stimulus?
Sorry it's unclear in the post, they weren't exactly the same! The numbers reported were on Lev, and we swept them around that range for me (Albert). But we didn't take down the exact values, so unfortunately I don't know how similar the maps were. iirc they were pretty different.
Maybe it's the resonance frequency of the sensor molecule?
Those few smells of extremes (garbage /clean air) make me think they are saturating the sensors.
I'm thinking it could be that we are very attuned to smelling bad smells because it's for safety.
Totally agree with both points! I would love to see what happens with more fine-grained control of the ultrasound.
The real question is that if you make it smell like garbage, will flys show up? Like is this a human experience, or a universal one?
The angle and position of the transducer would make them leveragable by future VR headsets.
After we have Smell-O-Vision[0] we should work on the next big step for the internet:
<[SA]HatfulOfHollow> i'm going to become rich and famous after i invent a device that allows you to stab people in the face over the internet
[0]: https://en.wikipedia.org/wiki/Smell-O-Vision
Interesting that burning was one of the smells. AFAIK that often comes up in neurological problems like strokes and epilepsy, so is it a particularly coarse sensation (like exciting all the different specialised neuerons at once)?. I imagine there's going to be a long challenge of targeting this to elicit more refined scents.
This seems interesting.
Me wonders if this can be applied to other parts of the brain, perhaps recalling long buried memories? In my case, "a 12‑lexeme mnemonic constellation that operates as a cognitive entropy incantation, each syllabic particle mapping onto a quantized shard of an authorization singularity’s randomness reservoir. This ordered cascade of linguistic quanta serves as a deterministic bootstrap constant, re‑materializing access to a distributed transactional continuum avatar via recursive derivation algorithms. In practice, it’s a compact neuro‑linguistic checksum spell, a bridge where human cortex patterns resonate with machine‑level information‑integrity archetypes, conjuring identity from chaos like a linguistic particle accelerator, aka ₿" ;)
This seems like poetry
"Which it be, ye scallywag, but nay—mark me well—’tis no tavern’s tall tale. Nay, ’tis truth carved in bone and blood, a story black as the Devil’s beard, yet truthful enough to make Death himself chuckle in his coffin." (╯︵╰,) / \ ₿
If they achieve their goals; I don't know of any tech company I would trust with a direct write access to my brain.
I shudder to think what capability the execute bit would grant.
You literally give them write access to your brain every time you interact with social media.
Very cool, although I found the link to LLMs toward the end to be a little odd.
Definitely, it’s a “we know the only thing anyone cares about right now is AI, so, look this is kind of like AI, sort of, if you squint”
Haha, luckily not! It's a very speculative link, so we didn't want to talk about "AI" too much in the main post. But we originally got interested in this concept because we are interested in other forms of input to the brain (other than the classic reading, listening, watching, etc). The nose is interesting because it seems to have many independent basis vectors and very sharp discrimination ability, so it might be a sensor into which you can pack many inputs. LLMs are just a proof-by-example that ~1k input dimensions is enough to really encode semantic meaning.
I'd personally be very sceptical that the human brain could derive much meaning from smell beyond "smells bad don't eat" or "reminds me of something", but I guess I would have said the same about creating smells via ultrasound so what do I know.
How do the power levels here compare with say a baby ultrasound?
What are the chances baby ultrasounds are doing this unintentionally?
Woah, that would be wild! It seems like most neonatal ultrasound reaches peak internal pressures of few-hundred kPa to 2 MPa. We ranged from 150-250 kPa. So, a little lower than the lower end of prenatal diagnostic imaging.
So, the pressures are high enough to be stimulating them! But most diagnostic imaging happens at 1-20 MHz, while most neurostimulation seems to occur at few-hundred kHz (we were at 300 kHz, on the mid-high end). So I don't think it's likely that babies are being sent smells?
I wonder if this makes you smell "laurax" or "olfactory white" if it glitches and triggers every receptor site simultaneously
https://en.wikipedia.org/wiki/Olfactory_white
That's a really interesting concept! The wiki page right now ends in "example of a combination of smells that neutralise each other", which makes me wonder if the "olfactory white" combinations are actually tuned to neutralize? I suspect what we're hitting is a bunch of receptors, and the brain is interpretting it as a common strong and evolutionarily important smell (which I assume has stronger pathways by default).
I was an organic chemist, and as such worked I've worked in various "wet" laboratories. All of them had store rooms and cabinets with hundreds or thousands of bottles filled with horribly smelling goop. Besides the occasional terpenoid (naturally occurring things smelling like menthol, cloves or cinnamon) nearly everything there was liquid death.
These smells have everything: Harsh solvent-like stuff like strong alcohol or glue, rotten fish amines, off-sweet halocarbons, things like burnt plastics, excrement, or stuff that defies description as to their lingeringly terrible sensation of olfactory wrongness (selenium compounds).
There is actually a thing called "cadaverine", that should tell you enough.
Still, every sufficiently large storage space I rememebet had this identical, not unpleasant, thickly sweet, but not easily defined smell.
So to conclude, I think it's a brain glitch when we input everything, all the smells, at the same time.
I could have sworn that sickly sweet smell was the smell of various phosphine reagents? Just my vague recollection of my time in lab from 15 years ago.
Phosphines, for me, were either odorless (for heavy ligand like things like triphenylphosphine) or absolutely rancid fishy mixed with a burnt chemical note. thankfully I never inhaled too many of the light organophosphines, they aren't too healthy...
Finally a solution to long term nuclear warning messages! [1] All we have to do is merely create an ultrasound emitter that works over a distance of meters and lasts several thousand years. Then assail our post apocalyptic adventurers with a stench so vivid it elicits ancient racial memories of global thermonuclear war.
[1] https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warnin...
I was about to buy a Steam Frame, now I have to wait for the version with the smell feature ;-)
No need to wait. It has an expansion port right over the nose for smell-o-vision.
Given that people can remember smell for years, this might be very useful for learning aid. Hook it up to an IDE and let people literally smell bad code as garbage.
Burning Smell or Trash doesn't give me a lot of confidence. Like pushing your thumbs into your eyes can make 'color' appear.
Interesting that the smells they were able to trigger seem to be related to basic survival. Smoke bad. Rotting food bad. Fresh air good.
Totally! We think this is because the brain is hard-wired evolutionarily to interpret smells by danger level first. So maybe there's just more "bad smell" receptors, or maybe the brain treats unknown smells as "uh oh, danger". Lots of cool stuff to test!
That doesn't surprise me.
Our fingertips feel using low frequency sound generated by our fingerprints passing over things.
I'm intrigued by the neuromodulation possibilities of this method, but I don't really understand how far can that ideally go. Since the authors are here, can you go a bit deeper in this? Thanks!
This would be very cool within a game setting. Just imagine feeling the sensation of fresh air as you go through a door. Even if it were small effects it could add a huge leap in realism and immersion. Smell is a very powerful sense.
> At the time, all of our headsets had a knife taped to the probe
is this like some second meaning or smth?
why is there a knife on the headset?
In case the smells make you go crazy, a failsafe system I assume.
Ha, nope. We needed something to stabilize the probe and the plastic knife from lunch was within reach :)
I cant wait for the day when the perfume and food shops in the mall use this for truly targeted advertisement. Cue rise of ultrasound-proof hats and lawsuits by people who report feeling sick due to such ads.
So they can already implement the smell of files restored from the Recycle Bin
Meditation and Pranayam practice also induce smells. I have experienced the smell of incense burning, fresh air etc
The adult videos industry must be already closely looking at this, and I wouldn't be surprised if they don't finance related research soon in the future, it will be VHS vs betamax all over again.
...
......
...OH you probably mean for the purposes of stimulating things OTHER THAN SMELLS
Yes, to simulate pheromones and related stimulus, that too, but I'm sorry if you already don't know this but a faint smell of urine would be a big deal to a non-trivial amount of men for immersion, without going into too much detail "squirting" fans and all the ecosystem around such kind of fetishes.
The natural progression of this technology is probably miniaturized transducer arrays on a chip, which would enable non-invasive write access to the entire brain.
This kind of tech should be developed as open-source projects, even for the firmware and hardware. A sufficiently advanced version of this, if widely deployed as proprietary blackboxes like smartphones are, would allow one consciousness to take over multiple bodies without their original owners knowing.
Can a machine detect smell? That bit is left unattainable.
that's an interesting mix of smells. i can't help but wonder if it's resulting from stimulation or the sensing of byproducts of the process itself.
If they’re using enough ultrasound energy to create a physical reaction inside the subjects head strong enough to smell like a burning camp fire, I can’t imagine they’d survive long enough to report it. Maybe I’m misunderstanding your implication?
maybe the ionized oxygen sensation, the ozone, the garbage and smoke are like a thin film of garbage and smoke particles in the nasal cavity experiencing mechanical stimulation. the mr guidance seems like a good idea, but the actual mount and targeting sounds crude, what are the odds it's just in the nasal cavity warming up and activating the gross stuff that lives in there?
i wonder if some kind of inhalable anesthetic would be a good control. ie, if the normal sensory pathways are blocked and the lifu stim of the olfactory bulb still creates the percept, then maybe it would be evidence that it is working as it appears...
Great idea for a control! Will have to try it if we set this up again..
doooooo ittttt :)
This experiment smells like weed
My prediction is that in the not-to-distant future, we’re all going to live indefinitely in simulations that optimized for human experience. To do this, AIs will “highjack” our nervous systems and feed generated worlds to use to experience. This kind of thing makes it seem like it’s pretty realistic.
I think a lot of people are already living in this future, trapped in a fantasy bubble world maintained by social media algorithms.
How do you know it hasn't already happened?
If it has already happened it’s shit and I want my money back.
This is so incredibly cool. Will a non-contact version be possible?
A scary concept... I think the hardest part would be coupling the ultrasound through the air. But there are probably solutions..
And this is why high-powered prenatal ultrasound has always concerned me (in fact the NHS advises against the commercial scans for this reason).
The NHS does nothing of the sort, in fact, they recommend them as safe and routine.
https://www.nhs.uk/pregnancy/your-pregnancy-care/ultrasound-...
> The scans are painless, have no known side effects on mothers or babies, and can be carried out at any stage of pregnancy.
If you read the linked article, you'd see that most of it focused on how extremely hard it was to get the ultrasound to do anything - it required an MRI and exact positioning of the ultrasound transducer. I doubt that 5 minutes of being gently prodded through the skin and fat is going to harm a child. Also, ultrasounds (and waves and radiation of all sorts) are passing into your body at all times, so it's not like they are exposing the fetus to something rare or unusual.
The NHS are less strident about this these days (I haven't checked since my sons were born - they used to dissuade 5d scans entirely), but this guide gives a flavour of the caution they invoke around private scans:
https://www.gov.uk/government/publications/uk-nsc-commercial...
A properly bizarre and interesting blogpost. Wow.
What kind of probe are they using?
Whomever smelt it dealt it.
...is this safe?
This is absolutely my question as well - curious if it's legal to do this, I'm guessing yes as it's an existing ultrasound device? But is there possibility of permanent damage?
It's objectively cool, but very curious about the safety as well.
This is the coolest part! Turns out, the powers you need are actually lower than what is used for imaging babies :) We measured our probe with a hydrophone on a computer-controlled scanner to get the pressure field, and made sure that it's below diagnostic levels (the generally accepted mechanical index limit is 1.9 and ours was 0.4 peak). We also made sure to avoid the eyes and keep thermals in check.
That's reassuring, but not entirely reassuring. Fetuses are a bit further from the emitter. You're focusing the pressure waves, but what about peripheral pressure waves disrupting the brain?
What would make it illegal to do this? Generally anything which hasn't been invented yet is legal, it's rare (but not impossible) for something to be banned before it exists.
My interpretation of what I've read of "off-label" medical device use... is that I don't think that's true at all. But IANAL or medical professional.
https://human.research.wvu.edu/fda-regulated-devices-used-in...
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9. Does FDA require IRB review and approval of off-label use of a legally marketed device?
...(unrelated for this conversation)...
Yes, when the off-label use of a legally marketed device is part of a research study collecting safety and effectiveness data involving human subjects, IRB review and approval is required (21 CFR 812.2(a)). For additional information on the off-label use of devices, see the FDA Information Sheet guidance, “ ‘Off-label’ and Investigational Use of Marketed Drugs, Biologics and Medical Devices.”
Listen up VR companies. We DO NOT WANT SMELL-O-VISION!
Who’s “we”? Like most tech, I can see this spreading quickly to the porn space.
From headline only, I see potential in crowd/riot control.
That anyone would direct a device towards their brain, intending the device to cause a physical impact on it, is amazing to me.
I wonder if — within the decade — “cheap porn smell” will be a recognisable thing
OK, I want to meet these guys. This writeup has several breathtaking (if you will) passages. Like:
> "We found different scents by steering the beam over ~14 mm (20 degrees at 4 cm radius). The distance between freshness and burning was ~3.5 mm."
> "The olfactory system potentially allows writing up to 400, if not 800 due to two nostrils, dimensions into the brain. That is comparable to the dimensionality of latent spaces of LLMs, which implies you could reasonably encode the meaning of a paragraph into a 400-dimensional vector. If you had a device which allows for this kind of writing, you could learn to associate the input patterns with their corresponding meanings. After that, you could directly smell the latent space."
This just makes me grin with total delight. Completely freaking fascinating.
I'm also extremely intrigued by the second quote. Definitely worth it to experiment in that area.
<3 email me or dm us on twitter! links on the post.
That is an amazing thought!
What about all the other senses?
Lev also found vestibular! Email or dm him on twitter :)
Can he stimulate happiness like TMS can?
Doing this via ultrasound might lower the barrier to treatment.
I want it the other way - I want google "search this smell" feature..
Ah reverse smell search? You'd need to upload the smell.
We are witnessing the dawn of smell-o-vision teledildonic VR tentacle porn
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Definitely not my fantasy. Just a funny image of the future.
> The olfactory system potentially allows writing up to 400, if not 800 due to two nostrils, dimensions into the brain. That is comparable to the dimensionality of latent spaces of LLMs, which implies you could reasonably encode the meaning of a paragraph into a 400-dimensional vector. If you had a device which allows for this kind of writing, you could learn to associate the input patterns with their corresponding meanings. After that, you could directly smell the latent space. A bit of ultrasound, a breath in - and you understood a paragraph.
Translation: We’re very concerned that the only projects getting funding right now have to use AI.
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