Posts Tagged ‘physiology’
“To sleep: perchance to dream: ay, there’s the rub”*…
I’m not the first person to note that our understanding of ourselves and our society is heavily influenced by technological change – think of how we analogized biological and social functions to clockwork, then steam engines, then computers.
I used to think that this was just a way of understanding how we get stuff hilariously wrong – think of Taylor’s Scientific Management, how its grounding in mechanical systems inflicted such cruelty on workers whom Taylor demanded ape those mechanisms.
But just as interesting is how our technological metaphors illuminate our understanding of ourselves and our society: because there ARE ways in which clockwork, steam power and digital computers resemble bodies and social structures.
Any lens that brings either into sharper focus opens the possibility of making our lives better, sometimes much better.
Bodies and societies are important, poorly understood and deeply mysterious.
Take sleep. Sleep is very weird.
Once a day, we fall unconscious. We are largely paralyzed, insensate, vulnerable, and we spend hours and hours having incredibly bizarre hallucinations, most of which we can’t remember upon waking. That is (objectively) super weird.
But sleep is nearly universal in the animal kingdom, and dreaming is incredibly common too. A lot of different models have been proposed to explain our nightly hallucinatory comas, and while they had some explanatory power, they also had glaring deficits.
Thankfully, we’ve got a new hot technology to provide a new metaphor for dreaming: machine learning through deep neural networks.
DNNs, of course, are a machine learning technique that comes from our theories about how animal learning works at a biological, neural level.
So perhaps it’s unsurprising that DNN – based on how we think brains work – has stimulated new hypotheses on how brains work!
Erik P Hoel is a Tufts University neuroscientist. He’s a proponent of something called the Overfitted Brain Hypothesis (OBH).
To understand OBH, you first have to understand how overfitting works in machine learning: “overfitting” is what happens when a statistical model overgeneralizes.
For example, if Tinder photos of queer men are highly correlated with a certain camera angle, then a researcher might claim to have trained a “gaydar model” that “can predict sexual orientation from faces.”
That’s overfitting (and researchers who do this are assholes).
Overfitting is a big problem in ML: if all the training pics of Republicans come from rallies in Phoenix, the model might decide that suntans are correlated with Republican politics – and then make bad guesses about the politics of subjects in photos from LA or Miami.
To combat overfitting, ML researchers sometimes inject noise into the training data, as an effort to break up these spurious correlations.
And that’s what Hoel thinks are brains are doing while we sleep: injecting noisy “training data” into our conceptions of the universe so we aren’t led astray by overgeneralization.
Overfitting is a real problem for people (another word for “overfitting” is “prejudice”)…
Sleeping, dreaming, and the importance of a nightly dose of irrationality– Corey Doctorow (@doctorow) explains: “Dreaming and overfitting,” from his ever-illuminating newsletter, Pluralistic. Eminently worthy of reading in full.
(Image above: Gontzal García del Caño, CC BY-NC-SA, modified)
* Shakespeare, Hamlet
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As we nod off, we might send fully-oxygenated birthday greetings to Corneille Jean François Heymans; he was born on this date in 1892. A physiologist, he won the Nobel Prize for Physiology or Medicine in 1938 for showing how blood pressure and the oxygen content of the blood are measured by the body and transmitted to the brain via the nerves and not by the blood itself, as had previously been believed.
“Count your blessings, but count your calories too”*…
We’re skating into that time year… the onslaught of celebratory meals and Holiday parties that promise to test our waistbands. But help– or at least a nagging caution– is at hand. The app Calorific uses simple, pastel images to reveal how much of virtually any food adds up to 200 calories.
From God’s condiment…
…to rabbit food…
More at “What 200 Calories of Every Food Looks Like.”
* Erma Bombeck
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As we go down for the count, we might send well-digested birthday greetings to William Beaumont; he was born on this date in 1785. An American army surgeon, Beaumont was the first person to observe and study human digestion as it occurs in the stomach. As a young medic stationed on Mackinac Island in Michigan, Beaumont was asked to treat a shotgun wound “more than the size of the palm of a man’s hand” (as Beaumont wrote). The patient, Alexis St. Martin, survived, but was left with a permanent opening into his stomach from the outside. Over the next few years, Dr. Beaumont used this crude fistula to sample gastric secretions. He identified hydrochloric acid as the principal agent in gastric juice and recognized its digestive and bacteriostatic functions. Many of his conclusions about the regulation of secretion and motility remain valid to this day.
Living at the end of the Long Tail…
click here for video
YouTube suggests that under 30% of its videos account for over 99% of it’s traffic. (The reigning champ: Justin Bieber’s “Baby, featuring Ludacris,” with 598,457,143 views… and counting…)
But what of the rest? Readers need no longer wonder. Dadabot “randomly finds the least viewed videos on YouTube (for better or worse).” Just click on over for selections that range from the poignant through the pointless to the putrid…
[TotH to Presurfer]
As we sit, transfixed, we might wish a responsive Happy Birthday to the Russian physiologist and psychologist Ivan Pavlov; he was born on this date in 1849. Pavlov’s experiments with animals (most famously, with dogs) led him to develop the concept of the conditioned (or conditional) reflex (a specific behavioral response to a specific stimulus), and laid the foundation for Behaviorism.
(Lest readers think Thomas Pynchon’s imagination overheated, it is now known that Pavlov’s experimental “animals” included human children.)
Pavlov’s 1904 Nobel Prize portrait (source)
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