[HN Gopher] Seeing how odor is processed in the brain
___________________________________________________________________
Seeing how odor is processed in the brain
Author : NickRandom
Score : 32 points
Date : 2022-06-05 09:02 UTC (1 days ago)
(HTM) web link (www.u-tokyo.ac.jp)
(TXT) w3m dump (www.u-tokyo.ac.jp)
| superb-owl wrote:
| > A team at the University of Tokyo created a special device that
| can deliver 10 diverse odors in a way that is accurate and timely
|
| I've always wondered how far off we are from being able to "3D
| print" tastes and smells. I had a machine learning professor tell
| me that chemoreception is the only sense that can't be decomposed
| into "eigensmells" or "eigentastes" - not sure if that still
| holds true today.
|
| They don't talk about the mechanics of this machine, but my guess
| is it just emits ten unique chemical compounds, rather than doing
| any kind of mixing.
| version_five wrote:
| I read an article about making perfumes (it was mostly about
| industrial scents like laundry detergent) that profiled someone
| who does that, and said the same thing as you re scents can't
| be decomposed. I'll try and think of where I saw it.
|
| Edit: https://harpers.org/archive/2021/12/the-odor-of-things-
| solvi...
| shagie wrote:
| > I've always wondered how far off we are from being able to
| "3D print" tastes and smells. I had a machine learning
| professor tell me that chemoreception is the only sense that
| can't be decomposed into "eigensmells" or "eigentastes" - not
| sure if that still holds true today.
|
| This gets into an interesting and controversial (in that
| scientists will argue about it) domain.
|
| Smell may be detecting the quantum vibrations of electrons.
|
| 2011: Flies sniff out heavy hydrogen -
| https://www.nature.com/articles/news.2011.39
|
| 2013: 'Quantum smell' idea gains ground -
| https://www.bbc.com/news/science-environment-21150046
|
| 2019: Human smell perception is governed by quantum spin-
| residual information -
| https://aip.scitation.org/doi/10.1063/1.5121155
|
| https://en.wikipedia.org/wiki/Vibration_theory_of_olfaction
|
| And for the other take on it:
|
| 2015: What's that smell? A controversial theory of olfaction
| deemed implausible - https://theconversation.com/whats-that-
| smell-a-controversial...
|
| Tangentially to the fly test: 2021: Heavy water tastes sweeter
| - https://www.pnas.org/post/journal-club/heavy-water-tastes-
| sw...
|
| > And in a taste test with noses plugged, over half did,
| suggesting that taste receptors on the tongue were indeed
| picking up the subtle flavor.
| rauhallinen wrote:
| There's some work on using ML methods to map from the
| structure of a molecule to an odor. Interesting to see where
| it goes, current results aren't that mind blowing:
|
| 1. B. Sanchez-Lengeling, J. N. Wei, B. K. Lee, R. C. Gerkin,
| A. Aspuru-Guzik, A. B. Wiltschko, Machine Learning for Scent:
| Learning Generalizable Perceptual Representations of Small
| Molecules. arXiv [stat.ML] (2019), (available at
| http://arxiv.org/abs/1910.10685).
|
| 2. J. Kowalewski, B. Huynh, A. Ray, A System-Wide
| Understanding of the Human Olfactory Percept Chemical Space.
| Chem. Senses. 46 (2021), doi:10.1093/chemse/bjab007.
|
| 3. L. Shang, C. Liu, F. Tang, B. Chen, L. Liu, K. Hayashi,
| Odorant molecular feature mining by diverse deep neural
| networks for prediction of odor perception categories.
| bioRxiv (2022), , doi:10.1101/2022.04.20.488977.
| revolvingocelot wrote:
| I suspect that might be harder than it sounds. See this
| (circa 2014) Aussie chemistry teacher's crowdsourced
| organic compound perceived-smell infographic -- it seems
| pretty random.
|
| [0]
| https://jameskennedymonash.wordpress.com/2014/01/04/table-
| of...
| shagie wrote:
| My favorite part of the vibration theory... from the
| Wikipedia article:
|
| > Carvone presented a perplexing situation to vibration
| theory. Carvone has two isomers, which have identical
| vibrations, yet one smells like mint and the other like
| caraway (for which the compound is named).
|
| > An experiment by Turin filmed by the 1995 BBC Horizon
| documentary "A Code in the Nose" consisted of mixing the
| mint isomer with butanone, on the theory that the shape
| of the G-protein-coupled receptor prevented the carbonyl
| group in the mint isomer from being detected by the
| "biological spectroscope". The experiment succeeded with
| the trained perfumers used as subjects, who perceived
| that a mixture of 60% butanone and 40% mint carvone
| smelled like caraway.
| mattlondon wrote:
| Aside: what is the "speed of smell"? I assumed it would slowly
| diffuse across the room, but when one of my kids has a dirty
| nappy/diaper it is like a lightning bolt in my nostrils from the
| other side of the room.
| liquidise wrote:
| This is a great question i'd love the answer to as well.
|
| My intuition tells me the speed particles passively would move
| through the air would be limited roughly by the speed of sound?
| That feels like a hard upper bound, though?
| 7373737373 wrote:
| I've wondered something similar, in particular about what
| happens when I open the window of a closed room. How fast do
| the gas compositions reach equilibrium again?
|
| Haven't found an answer yet even for very simple assumptions,
| e.g. 1m3 cube room, 0.01m2 window.
| version_five wrote:
| It's governed by diffusion. There is an equation ( Einstein eq.
| I think) that says something about the average distance
| diffused being proportional to sqrt(time) and a diffusion
| coefficient which depends on what is diffusing and in what
| medium. the units of the diffusion coefficient are in m^2/sec
| because of the square root dependence but it's sort of an
| analog to the speed.
|
| Delta x = Sqrt(6 _D_ t) in 3d
|
| It's based on brownian motion leading to a gaussian
| distribution of distances travelled
| zasdffaa wrote:
| In still air surely so, where people are I guess there's a
| lot of convection.
| [deleted]
___________________________________________________________________
(page generated 2022-06-06 23:02 UTC)