Otoliths

December 3, 2008 4:00 PM

The Orienting Stone. "A snowy white stone that gives shape to the universe: as it happens, we all carry within our skulls the vestige of such a thing, a kind of existentially reversed qibla (this one perspectival, the other metaphysical) that gives us our sense of being at the center of things, the sense that we are upright at the origin point of a three-dimensional space..." [Via]
posted by homunculus (21 comments total)

Fascinating article on something I've never heard of before, thanks!
posted by justkevin at 4:10 PM on December 3, 2008

The “otolithic organs,” as they are known, are a pair of sensors—the utricle and the saccule—nestled in the labyrinthine architecture of the inner ear. Grossly speaking, each consists of a bunch of tiny pebbles (of the white rock known as calcium carbonate) embedded in a gooey wad that sits atop a carpet of delicate hairs. The saccule is roughly vertical in our heads, and the utricle more or less horizontal. Together they orient us in the world, since they work as tiny inertial references: raise your head suddenly (or get in a jerky elevator), and the pebbles of the saccule get momentarily left behind as your skull starts upward; this bends down the hairs against which those pebbles lay, and the sensitive hairs function like switches, sending signals to your brain that you register as a feeling of ascent. The utricle does the same work for motion from side to side, and between them these tiny organs generate the neurological data that give us our normal sense of being in the world

that is SO cool.

homunculus, another gem of a post. how absolutely fascinating. thanks, as ever, for broadening my world in meaningful and unexpected ways!
posted by CitizenD at 4:14 PM on December 3, 2008

Whatever. When you're ready for the real truth...
posted by Joe Beese at 4:19 PM on December 3, 2008

Awesome. Great link.
posted by billysumday at 4:20 PM on December 3, 2008

As above, so below.
posted by Roach at 4:42 PM on December 3, 2008

Great essay. Thank you.
posted by eritain at 4:44 PM on December 3, 2008

Woah, that was great. I was all prepared to be dismissive, 'cause, hey, I took highschool Bio too. I'm glad I kept reading.

Now I want to scalp some fish.
posted by lekvar at 5:52 PM on December 3, 2008

That's fascinating. I wonder how they analyze the "growth rings" and deconvolute the various effects of temperature, salinity, etc.

Thanks for another neat post, homunculus.
posted by Quietgal at 6:07 PM on December 3, 2008

If you face the other way does it become the occidental stone?
posted by pianomover at 6:14 PM on December 3, 2008

Ah cripes, beaten to doing an eponymous post. Well, at least it's a great otolith article. I used to work in the summers at a salmon hatchery in Alaska that used thermal marking on otoliths to mark birthplace and year. Here are some photos where you can clearly see the thermal bands. They are very distinct and precise. Incredible use of a natural growth feature. I spent many a sleepless night on cannery slime lines and on pitching seiners dissecting out those earstones. My other big exposure to otoliths came when I experienced an accute bout of Benign Paroxysmal Positional Vertigo, caused by the human version of an otolith knocking around loose inside my inner ear. Really made me appreciate the smooth functioning of a properly placed otolith. I also really like the sound of the word. otolith otolith otolith otolith otolith.
posted by otolith at 6:43 PM on December 3, 2008 [5 favorites]

But about thirty years ago a curious geologist, tinkering with an otolith (it was a rock, after all), made the truly shocking discovery that those annual layers can be further resolved, microscopically, down to daily layers, layers that contain, in their chemical composition and size, information about the temperature and the salinity of the water through which the fish moved, the food that it ate, and various environmental contaminants it encountered.

Holy shit.

Flagged as fantastic. Thank you, homunculus!
posted by rtha at 8:08 PM on December 3, 2008

Nifty
posted by Smedleyman at 8:20 PM on December 3, 2008

reminded me of the eigenstate mod in egan's _quarantine_ for some reason! oh and schild's ladder :P
posted by kliuless at 8:24 PM on December 3, 2008

And here's a PDF on how to convert a standard record player into an otolith grinding apparatus. Hmmmmm, using a music producing machine to grind down one of the structures of the inner ear..... I've used one of these, worked great.
posted by otolith at 8:35 PM on December 3, 2008

WOW!

I just finished reading all about the utricle and the saccule in this great book about human infant brain development-- apparently the whole vestibular system is one of the first things to develop in the fetus' sensory apparatus, and it's pretty much completely mature by the time the baby is born. Which means my 6-week-old daughter totally knows which way is up.

But that's nothing compared to the wonder of the otolith!

Otolith! Otolith!
posted by otherthings_ at 8:36 PM on December 3, 2008

I am totally feeling the stone now.

Wait, what?
posted by The Whelk at 8:45 PM on December 3, 2008

Thanks for this post.
posted by pointilist at 9:26 PM on December 3, 2008

Hacking Salmon's Mental Compass to Save Endangered Fish
posted by homunculus at 9:48 PM on December 3, 2008

In archeology field school I was crowned the Otolith Queen for my weird eye for otoliths hidden among the oyster shells of the dig we were doing on Little Saint Simon's Island, Georgia. And in the lab it was fun to try to determine the diet of those early Georgians based on their shape. But I had no idea that otoliths are quite THAT awesome!
posted by gemmy at 10:04 PM on December 3, 2008

Did you make it to the Otolith Olympics?
posted by homunculus at 10:13 PM on December 3, 2008

otherthings_ writes "I just finished reading all about the utricle and the saccule in this great book about human infant brain development-- "

You'd like Neil Shubin's Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body. Very readable comparative anatomy/physiology for laymen.
posted by orthogonality at 11:04 PM on December 3, 2008