Saturday, May 28, 2016

Hella Fumes

New Jersey is home to many of the world’s perfume makers. Eric Schlosser, in his Fast Food Nation 2001, calls it the Flavor and Fragrance Corridor (referring to the strip of I-95/NJTP that runs through the middle of the state and upon which are located many buildings critical to the global flavor and fragrance industries.)

It’s no wonder that someone would come up with the bright idea to steal a buttload of perfume from one of these places. $30,000 worth, right in the trunk of his car.

So that’s what a trunk’s worth of perfume costs. But wait, let’s consider this – the ingredients themselves cost about 100 times less, which is 300 bucks. Which one is crazier: that you can get a year’s salary by filling a uhaul with stolen perfume, or that fragrance designer (under the guise of a brand name of course) can turn one dollar of oil into a one hundred dollar bottle of oil?

Then again, Salvatore Dali was known for saying that all artists are alchemists because they turn paint into gold. Those fake Vermeers sure went for tens of thousands of dollars, and well, they weren’t even “real” paintings.

May 2016,


(about the Vermeer forgeries)

Wednesday, May 25, 2016

Popcorn Pee

The bearcat, an animal from Southeast Asia, marks its territory with popcorn-smelling urine. Researchers, i.e. professional piss-sniffers, used gas chromatography-mass spectrometry to identify the compound 2-acetyl-1-pyrroline in the bearcat’s urine. This is the same compound that gives popcorn its smell. It forms when heat drives a reaction between the sugars and amino acids in the kernel. A similar thing happens when bread is toasted and when rice is cooked.

The researchers say that with the bearcat, the compound 2-AP is probably created when the animal’s urine combines with microorganisms living on its skin and fur. These microorganisms break down the urine in the same way human-armpit microorganisms turn our sweat into “body odor.”

Although popcorn is an unusual example of body odor, for sure, it is considered one of the ten primary categories of smell. It should be noted that this very recent method for classifying odors is pretty loose, meaning the categories are not rigidly defined, and by viewing this chart, one can see the slight alterations that are almost as acceptable. Researchers used  statistical analysis to condense the categories into the following list: Fragrant, Woody/resinous, Fruity (non-citrus), Chemical, Minty/peppermint, Sweet, Popcorn, Lemon, Pungent, Decayed.

Notice here the persistent difficulty in organizing smells – one category requires its own disambiguation (fruity non-citrus), and one isn’t even a smell (sweet).

The organization of smells is an arduous task, and although a handful of people have tried, none have been successful. Using statistical semantic analysis is a relatively new approach. They began with a standard catalogue of odors, taken from the Andrew Dravniek's 1985 Atlas of Odor Character Profiles (144 odors, I believe). Upon this, they do a form of statistical analysis called non-negative matrix factorization (NMF). NMF is a dimensionality-reduction technique, which makes it handy for categorizing the perceptual space of smell.  It has to do with confusing things like normalization and consensual matrices, but all we need to know here is that a huge network of smell descriptors are matched against each other to measure their similarity, both to each other, and to a baseline. Each descriptor is then given a kind of similarity score. The descriptors that are the most similar to others are then called the primary categories.

A hypothetical corpus of all possible smells is a multidimensional thing that has never been (and perhaps can never be) reduced to a small set of categories like colors or musical notes. Statistical methods such as NMF reveal that smells are not evenly spread throughout odor-space, meaning that they are not equally different from each other. Instead, they form clusters of similarity, albeit a very loose clustering. As the scientists note in their paper, “Because NMF is an iterative optimization algorithm, it may not converge to the same solution each time it is run (with random initial conditions).” -source

This method, which provides not answers but approximations, turns out to be quite appropriate. The odor lexicon is an ephemeral thing, like smell itself. It is a precognitive perception which bypasses the language centers of our brain, yielding an unpredictable set of descriptors that will change with the verbalizing person. I just wonder – in cultures where they don’t have popcorn, what would they call bearcat piss?

Notes:, April 2016

Castro JB, Ramanathan A, & Chennubhotla CS (2013). Categorical dimensions of human odor descriptor space revealed by non-negative matrix factorization. PloS one, 8 (9) PMID: 24058466.

see this chart listing of other potential primary categories

Saturday, May 21, 2016

On Thinking Like a Human

Intuition Algorithm download in progress

The computer processing analogy that we use for describing the way the mind works matches only the more rational side of human thought, and the senses most associated with them (vision and sound). Or at least that’s the way it used to be, before the AlphaGo defeat.

Other ways of thinking are more intuitive, and more in line with the primitive senses (smell). These types of thinking are becoming more important, because they are more analogous to what it means to be human today, as compared to a computer, that is. It turns out that humans are not rational enough to integrate with computers, i.e. robots; the problem with self-driving cars is that they’re too rational; they follow all the rules, all the time, and humans don’t.

What we bring to the table, as humans rather than algorithms, is the ability to make intuitive decisions based on accumulated experience. I’d like to point out that this accumulation is called memory, and although it is “stored” in the brain, it requires a body to get there in the first place. This is one of the main reasons why olfactory perception can be such fertile ground for research.

Basically, humans would rather guess than go through a bunch of bad options. Sometimes we’re wrong, but when we’re right, we just saved a whole lot of processing power.

In this study, a huge group of game players was tasked with solving a very complex problem. Instead of running every possible solution, which would take forever, the players search intuitively. And the study showed that this intuition-searching happened to be similar for each of the individual game players, hinting at a possible “intuition algorithm” for the future of computing. If investigating the artificial unconscious looks like a good bet, then we might see the half-primitive half-cognitive “language of smell” gain some attention soon.

Notes:, May 016

Wednesday, May 18, 2016

Brainless Intelligence

Many-headed slime mold aka Physarum polycephalum, image via the French National Centre for Scientific Research, 2016 

Some folks made slime think. The lowly slime mold, a single-celled protist, shows evidence of learning. It remembers the particular route that avoids irritants placed in its path by tinkering scientists. Yup. Funny thing is, the organism investigated is commonly called the “many-headed slime.” This turns out to be an ironic name, for this organism, without a central nervous system, acts like it does in fact have a head, or a brain, and maybe more than that – many heads, and many brains.

This isn’t the first time slime mold has done amazing feats. It’s used to recreate roadmaps from ancient cultures, or Tokyo’s rail system, just based on topographical information. Who do these single-celled organisms think they are, acting like they have brains? This raises the following question: Where does intelligence come from? Does it need a brain?

In Hidden Scents, while talking about the evolution of the smelling organism, I suggest that the mind is first, and then comes the body. There is something thinking in the most primitive of organisms, deciding which molecules in its surrounding sea of life, and proto-life, should be taken into it, to become part of it, and which molecules should stay outside. To be alive, one of the most basic requirements is to have a boundary between the living thing and the outside. This defines the body. But how does this body, living in a sea of potential bodyparts, determine which parts to keep, and which ones to leave behind. The body comes from somewhere, doesn’t it? And isn’t a body - a living body - more than just a bunch of molecules? If so, what’s organizing those molecules? Who is running the show?

Chemosensation is the basis of this interface, and is the process by which human olfaction works. The initial decision-making algorithms to run with this chemosensation are also the base-algorithms of human thought. Rational thought is a much more complex affair, but at the base is the limbic system, and in smelling we have a model for the kind of thinking performed by a simple, multicellular organism. Or even a collection of single celled organisms, perhaps?

Our current mode for thinking about intelligence is undergoing a major reboot. In light of developments in artificial intelligence, the boundaries of human intelligence are already blurred – many of the things once considered human, rational thought are now programmed into an "artificial life form," i.e., a computer program.

But that’s ok, because current models of the brain follow the schematics of a computer in the same way the nervous system was initially thought of as a closed network of fluids and the brain a pressure-modulator. This was in the age of hydraulics, before we knew what electricity was. Now we know what a computer is, and so the brain is like a computer. Tomorrow, we may know what life is; will we then compare the brain to it?

Our ideas on thinking and intelligence necessitate a brain (whether it’s a computer or a water pump or a lifeform). It's very counter intuitive to hear that things without brains can think. Who knows, next it will be like “Things without bodies can think.” Does the temperature in a room think? Does it have a memory?

May 2016,

Laura Sanders, Wired, via Science, 2010

Mar 2015,

Sunday, May 15, 2016

Semantic Atlas Shrugs

credits: University of California Berkeley 

Research at the University of California Berkeley has consecrated a semantic atlas of the brain, and reorganized our understanding of the entire semantic system in the process.

It was previously thought that word-memory was concentrated into certain semantic groups throughout the brain. Now we know that they’re scattered everywhere. Not only that, the pattern of distribution is quite similar from person to person.

In the study, volunteers listened to a radio program while active regions of their brain (showing more blood flow) left their mark on a timestamped map. Scientists later matched the words of the radio show to the brain’s activity map to create this “semantic atlas”.

Although the semantic atlas is now known to spread across the whole cerebral cortex, the researchers revealed groupings into the following areas: mental, emotional, social, communal, professional, violent, temporal, abstract, locational, numeric, tactile, and visual.

The same word can show up many times in the atlas. Words with abstract meanings and words related to the body populate many regions of the atlas.

Taken from the BBC article:
“For example, the word "top" was represented in a part of the brain that responds to words about clothing and appearance, and also in a region that deals with numbers and measurements.”

see a more detailed map of the semantic atlas here at Nature:

Sunday, May 8, 2016

Recognizing Science Communication

Actor, director, writer, and science communicator Alan Alda in his MASH days

Science can be confusing. It’s great to see science communication being recognized as a public welfare.

From the Alan Alda Center for Communicating Science:
The National Academy of Sciences is presenting its 2016 Public Welfare Medal to actor, director, writer, and science communicator Alan Alda in recognition of his "extraordinary application of the skills honed as an actor to communicating science on television and stage, and by teaching scientists innovative techniques that allow them to tell their stories to the public." The medal is the Academy's most prestigious award, established in 1914 and presented annually to honor extraordinary use of science for the public good.”

Saturday, May 7, 2016

Phantom Smells

Pan’s Labyrinth – partially related image

I’ve been venturing into an interesting offshoot of everyday smell phenomena – the world of the Industrial Hygienist. Here we’re talking about phantom smells and indoor air quality, or what is sometimes called more broadly, indoor environmental quality (IAQ/IEQ).

I came across a post by an industrial hygienist proselytizing the use of one’s nose over more ‘scientific’ instruments of measurement to solve odor problems.

The problem is, when an industrial hygienist is hired to solve an odor issue, they are expected to give hard numbers based on measurements of the temperature, humidity, and composition of the air. Numbers lend credibility, putting a façade of certainty on your claims. But sometimes the numbers don’t get to the root of the problem. Smells are so evasive, so ephemeral, that they require more penetrating investigative work than the kind of data a hygrometer-wielding robot can produce. (However, don’t discount the photoionization detector, he says, as it detects very small amounts of odor compounds and can point you in the direction of a specific pointsource – like an old lunchbag.)

In the article, What’s That Smell, we get a few explanations for the origin of “that smell” that’s been haunting your office. As usual, the comments section yields some good odor-vocab to help us unravel the most impossible lexical behemoths.

I’ll copy some highlights from Mr. Jack Springston’s article here:
Rotten eggs and sewer-smells – pretty much sewer gas; it’s usually blocked from pumping upwards through your plumbing, until the trap dries out do to disuse or whatever; turn the faucet on to fill it back up, but make sure it’s not a natural gas leak!
Dirty sock – bacterial growth on air conditioning coils
Vomit/butyric acid – certain ceiling tiles can make this smell when they get wet; who knew?
Good old mold  – besides making the obvious visual inspection for water damage, check the air vents, as sometimes the mold growth is right there on the vents themselves; ironic.
All-purpose phantom odors – check the air vent system; sometimes the building’s innards are connected in surprising ways, and they might take a smell from one place and send it through a maze of ducts to the intake vent in your room.

     Jack Springston, Industrial Hygiene Program Manager at TRC Environmental, an engineering, environmental consulting and construction management firm.
     This article was originally published in the November 2015 issue of Healthy Indoors Magazine

Suspense is in the Air and It’s Called Isoprene

Researchers investigated the air in movie theaters to learn how to predict the level of excitement in the show being watched. The revealing chemical patterns exhaled in this “crowd breath” are most clearly noted during suspenseful scenes in movies, and are consistent across multiple viewing audiences. The scientists say the rise in both CO2 and isoprene are a result of the accelerated breathing induced by a suspenseful movie scene.

May 2016,

Jonathan Williams et al. Cinema audiences reproducibly vary the chemical composition of air during films, by broadcasting scene specific emissions on breath, Scientific Reports (2016). DOI: 10.1038/srep25464

Wednesday, May 4, 2016

The Persistence of Microbiomes

This is sand under a microscope 

So much is being discovered about the microbiome that it’s hard to keep track. Personally, I’m not sure whether to call these new understandings common sense, or counterintuitive.

It turns out that despite our being exposed to a relentless onslaught of other people’s microbiomes, and the microbial maelstrom that is our daily environment, our own personal microbiome remains very stable.

Some places on our bodies, like moist places of the armpits, feet or groin areas, showed high microbial diversity and were the least stable over time. Although, scientists suggest this may be a result of personal hygiene practices.

May 2016,

February 2, 2016