Neural Cartography

This first article doesn't sound like the cartography I came here for, but it's in the title so...

Researchers present insight into the neural cartography of smell

Oct 2022, phys.org

https://medicalxpress.com/news/2022-09-insight-neural-cartography.html

Honestly I'm unclear as to what this means; the endoplasmic reticulum has some mediating influence on the neural computations that turn olfactory receptor stimulus into the olfactory perception of a specific odorant?

"It is mind-blowing," said Dr. Lomvardas, also a professor of neuroscience and of biochemistry and molecular biophysics at Columbia's Vagelos College of Physicians and Surgeons. "This system found a way to create a genetically encoded, hard-wired means of transforming randomly-chosen receptor identity to a very precise target in the olfactory bulb."

Perhaps, olfactory neurons are not alone in the way endoplasmic reticulum stress organizes their wiring with downstream neurons. "If it turns out that all neurons do this, this discovery could help us understand much more about the brain," said Shayya.

via Mind, Brain and Behavior Zuckerman Institute at Columbia University:  Hani J. Shayya et al, ER stress transforms random olfactory receptor choice into axon targeting precision, Cell (2022). DOI: 10.1016/j.cell.2022.08.025

https://dx.doi.org/10.1016/j.cell.2022.08.025

Image credit: AI Art - Number Two Number One - 2022

Here's another article that makes reference to "maps" but isn't actually about navigation...

Mapping the path from smell to perception

Nov 2022, phys.org

https://medicalxpress.com/news/2022-10-path-perception.html

"The last frontier of sensory neuroscience"

Because previous studies of the olfactory cortex failed to find any logical organization among neurons there, many neuroscientists suspected information about odors was relayed randomly through the brain. But those studies examined connectivity patterns of just a few dozen neurons.

DNA-based brain-mapping technologies charting the way sensory information is routed between olfactory-processing parts of the brain including the olfactory bulb, which receives sensory information from the nose, the primary smell-processing hub called the piriform cortex, and several other brain regions that receive inputs from the olfactory bulb.

via Cold Spring Harbor Laboratory: Yushu Chen et al, High-throughput sequencing of single neuron projections reveals spatial organization in the olfactory cortex, Cell (2022). DOI: 10.1016/j.cell.2022.09.038

https://dx.doi.org/10.1016/j.cell.2022.09.038

And finally, a little something about how we use olfaction to navigate...

Flies smell the motion of odors and use it to navigate, study finds

Nov 2022, phys.org

https://phys.org/news/2022-11-flies-motion-odors.html

Flies can sense the direction of moving odor packets themselves, not just the wind.

Cool study design: They genetically modified fly antennae to detect light, then created fictive odor packets out of light and watched how the flies responded to these signals in both windless and windy environments.

via QBio Institute at Yale: Nirag Kadakia et al, Odour motion sensing enhances navigation of complex plumes, Nature (2022). DOI: 10.1038/s41586-022-05423-4

https://dx.doi.org/10.1038/s41586-022-05423-4

Temporal Patterns in Olfactory Perception

Temporality in olfactory perception is understudied. But as our ability to measure spike activity over small timescales improves, so will our understanding of olfaction, and human behavior in general.

On Time

Facebook knows what's up; they're making Time Cards for computers and networks so they can perform better, and integrate information better. They understand the mismatch between the size of today's clocks vs the speed of information. 

Today's clocks go down to the picosecond (trillionth of a second), and some things are being measured at the femtoscond (quadrillionth of a second). There's even some zepto-sensitive devices out there. The smaller the time-slice, the better your pattern recognition. Even back as far as Barabási's Bursts (2010) we knew that high resolution temporal patterns could be really informative of network behavior. More people in your study is also helpful, but networks like Facebook are running out of people* (but bots are infinite!), so they have to find another way of mining user data, hence an interest in temporal activity. 

If you think the fine-grained timing of patterns isn't that big a deal, why don't you ask the New York Stock Exchange, which is actually not located on Wall Street, but a few miles away in Carteret, New Jersey, because high frequency trading algorithms compete with each other at such high speeds (the speed of light) that they need the extra light-seconds provided by placing their servers a few miles closer to the international trunk connecting the Internet to the United States (it's called a latency advantage; and that trunk actually lands in Manasquan, a town on the Jersey Shore; still, closer to Carteret than New York).

The point here is that light travels fast, and if we want to understand it, then we will need to look at smaller and smaller slivers of the clock, and add this to the growing body of knowledge about how.

On Olfactory Timing

Think about it -- the brain is a network of billions of blinking neurons. Consciousness, or any neural activity, is an intelligent organization of these blinking neurons into meaningful patterns. But when you have billions of lights blinking on and off at the same time, you need to start slicing up the "time," so it's not all happening "at once." 

In the world of olfactory perception, a new look at the temporal side of things should supplement the intense interest we're seeing in this subject (check out the books Smellosophy or Nose Dive, and stutter at the thought of a $2 million grant in olfactory artifact research).

The author of Smellosophy, Barwich, actually gets into this aspect of olfaction. For her, it's a major distinction in the way we categorize olfactory information - between the historical approach to "mapping" the receptors of the two-dimensional olfactory bulb to "measuring" the timing of receptor activity, which includes the temporal dimension.

She argues that the measurement approach can reveal a key to the coding of the olfactory network. Olfaction is not just about identifying the different molecules present and their combinatorial patterns, but about when they appear and at what concentrations, and how these concentrations change over time. After all, olfaction is about detecting change, which implies time.

She says, "Rather than molecules, your brain depicts transient information patterns" (p246)

-Smellosophy: What the Nose Tells the Mind, A.S. Barwich, 2020, Harvard University Press

http://www.smellosophy.com/

And here's a recent article on the topic:

Fast changing smells can teach mice about space

May 2021, phys.org

https://phys.org/news/2021-05-fast-mice-space.html

Mice can sense extremely fast and subtle changes in the structure of odors and use this to guide their behavior. The findings, published in Nature today, alter the current view on how odors are detected and processed in the mammalian brain.

via The Francis Crick Institute: Ackels, T., Erskine, A., Dasgupta, D. et al. Fast odour dynamics are encoded in the olfactory system and guide behaviour. Nature (2021). doi.org/10.1038/s41586-021-03514-2

Post Script:

Start with the 2014 article from Princeton (cited below) that said Facebook is losing its users like a susceptible-infected-recovered model of disease transmission, and that it would be done by 2018. Granted the article came from the unlikely Department of Mechanical and Aerospace Engineering in Princeton, and despite all the bad press, we can now fast forward to 2018 when Facebook is suspected to be more bots than people. Or is it that the people are acting more bot-like as they co-evolve with engagement algorithms in the artificial arena of natural selection. Bottom line is, social media networks, and all technologies adopted by individuals in a society, will follow a similar disease model. 

Not to mention, the bad press (possibly influenced by the same entity that took a full-page ad in the New York Times btw, and somewhere around 100K in case you were wondering) didn't age well.

But I'll let you be the judge of that:

"Facebook may be a massive drain on our attention that some people get sick of, but that doesn’t mean it actually operates like a virus." -TechCrunch, 2014

Epidemiological modeling of online social network dynamics, John Cannarell, Joshua A. Spechler. Department of Mechanical and Aerospace Engineering, Princeton University. arxiv:1401.4208v1 [cs.SI] 17 Jan 2014. https://arxiv.org/pdf/1401.4208v1.pdf

Post Post Script:

Zeptoseconds - New world record in short time measurement

Oct 2020, phys.org

https://phys.org/news/2020-10-zeptoseconds-world-short.html

Urban Scentsations

Odor investigators engaging in a smell hunt. source

Let’s take a minute to recognize this exceptional olfactory artist, Kate McLean. She works with human perception and the urban smellscape. She basically turns the city into her own little laboratory, running perception experiments on the people there, and coming back with sensory analyses that you just can’t get in an actual lab setting. She does smellwalks, smell sketches, and all kind of other activities to both help people explore and appreciate the most overlooked aspect of their urban environment. As a result of her work, we get these Smellmaps, something not taken up by Google yet…yet. Please check out her site here, and get upset that she already came to your neighborhood, or excited that she didn’t yet!

Sensory Maps

Research, analysis & design of Sensory Maps by Kate McLean

Music, Maps, and Categorgonzola

Screenshot from Genealogy and History of Popular Music Genres from Origin till Present (1870-2016)

(highlighting my own personal favorite genre-neighborhood, the drum n bass part of town)

A Dizzying Infographic Traipses Through 146 Years of Music

WIRED, June 2016

A polymathic Belgian architect named Kwinten Crauwels has created a map worthy of praise for anyone who stays up at night thinking about how to articulate vast networks of cultural products.

The Music Map is an “interactive infographic that maps the definitions, relationships, and sub-genres of the last 146 years of pop music.

 It’s formally called “Genealogy and History of Popular Music Genres from Origin till Present (1870-2016)” and it’s creator certainly echoes my own struggles to organize the language of smell:

“You can never create the ultimate genre map—there is no such thing, because it’s a sociological reality, not a scientific one,” Crauwels says. “But you can at least create a very good approximation, so people can learn more.” He’s right; Crauwels has built a chart that’s actually chart-worthy.

-quotes taken from WIRED

POST SCRIPT

On Vague Notions of Accuracy

-About the confusion matrix, a great starting point for anyone who is trying to organize things, but is ultimately doomed to failure.

Network Address, 2013