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Posts tagged with brains

Robert Sapolsky on the Limbic System (por StanfordUniversity)

  • olfactory bulb takes up 40% of a rodent brain’s projections
  • rhine encephalon — originally viewed as to do with olfaction in all species
  • gathers whatever sense-data pertains to emotions
  • Paul McLean’s triune brain (phylogenetic conservation): hypothalamuspituitarybrainstemmidbrain⊕thyroid⊕pancreas⊕heart (robotic, boring—until it goes wrong) + the limbic system (mostly a mammalian invention: birds, reptiles, fish have less complex limbic systems) ⊕ emotional complexity + cortex (gleaming analytical machine of cognitive expertise — greatly expanded in vertebrates, in mammals, in primates, in us — cortex tied to limbic system, not independent)
  • decisions made under duress
  • think about your own mortality (kicking out “CRH”)
  • so limbic influences cortex and vice versa
  • we are “a fancy species”
  • Odene’s curse — lose the capacity for automatic breathing (you die of sleep deprivation)
  • Antonio DiMasio, Descartes’ Error
  • James Pabes
  • the limbic regions compete to control the hypothalamus (they can shush each other up)
  • edge/network/synaptic distance to the hypothalamus
  • every sense has to go through ge;3 synapses to tell the limbic system anything—except olfaction can hop 1.
  • olfaction takes up only 5% of our brain
  • grey matter (nuclei) vs white matter (axon cables wrapped in myelin)
  • amygdala, hippocampus, septum, mammilary bodies, hypothalamus, thalamus, prefrontal cortex
  • frontal cortex: where am I being touched? which note are you playing? how do I do long division? which limb do I want to move? plus long-term planning, gratification postponement, emotional regulation, impulse control
  • frontal cortex is most recently evolved, relatively largest in humans, not fully mylenated until age 25;size of prefrontal cortex in primates grows as size of typical social group
  • amygdala tells you to be afraid and pings the hippocampus: “Hey, remember to be afraid of this in future”




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The Enclosures (45 min)

I had no idea that so recently people roamed about each other’s land, no fences dividing the farms and folds.


http://upload.wikimedia.org/wikipedia/commons/9/9e/Mississippian_cultures_HRoe_2010.jpg
 


File:Mott Mounds Coles Creek culture HRoe 2011.jpg

http://upload.wikimedia.org/wikipedia/commons/b/b3/Eaker_Site.jpgMoundville site
Mound and pit


Uxmal Mexico Map

File:View from Pyramide de la luna.jpg


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http://www.mexicovacationtravels.com/wp-content/uploads/2010/04/Mayan-Ruins-Tulum-Mexico-pictures.jpg

http://ambergriscaye.com/pages/mayan/art/cerros22sm.jpg
http://ambergriscaye.com/pages/mayan/art/lamanai.gif


http://ambergriscaye.com/pages/mayan/art/xunantunich22sm.jpg
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http://static5.businessinsider.com/image/4dc1578ccadcbbd57f130000/image.jpghttp://ambergriscaye.com/pages/mayan/art/cuello22sm.jpg

http://ambergriscaye.com/pages/mayan/art/lamanai22sm.jpg

The modern structure of towns, like so many things, is an outcome of economic structure.

  • When shepherds no longer roamed freely through the hills
  • and it became efficient for homes to be built in a rotary array around some kind of centre,
  • then pubs (public houses = free houses) became the meeting place

This is one of the most influential things I’ve heard, period. Think about how much longer you have to walk and how much lonelier life became once you don’t cut across another person’s land.

  

My pessimistic image of the culture that I live in is

  • city people all in their separate flats, with their separate computers, or separate televisions, on separate couches, alone in the space they’ve paid for with the career they fought to dominate
  • going out to a restaurant, pub, or coffee shop to experience the unexpected bumpings into people
  • so everything costs money. It costs money to have friends, costs money to hang out, costs money to flirt, costs money to meet people, costs a lot of money to meet rich people, costs money to put yourself in a place where people will happen to encounter you—unless you do it over the internet—and then people wonder why nobody makes friends after college
  • suburban people the same, except also having their own pools instead of sharing a community pool
  • having their own medium-sized lawns — big enough to keep the neighbours from peeping in the window, or seeing you on the porch and say hello — instead of sharing a large park cutting all the medium lawns down to small lawns (not that they individually choose this — the decision is made by real estate developers)
  • country people even more isolated because land tracts are so huge
  • and nobody, but nobody, knows their neighbours.

William GedneyYoung girl standing on a porch leaning against a support beamKentucky, 1964[via the Duke University Libraries]
rocksteady
http://www.everyculture.com/images/ctc_02_img0346.jpg

Coney Island, 1984



More old New York


brooklyn

Danny Lyon/ NARA
Apartment house across from Fort Green Park in Brooklyn

On Bond Street in Brooklyn

Boys in Brooklyn

Fourth Annual Veuve Clicquot Polo Classic
Fourth Annual Veuve Clicquot Polo Classic


Basketball playground in Brooklyn

http://www.tfaoi.com/am/7am/7am322.jpg









Crooklyn told you what to dream

This is no 1970’s Brooklyn or 1950’s Appalachia, with people sitting on their porches and knowing each other and generally being outside and around each other at the same time.

  • When I think about more "primitive" cultures, I imagine if I’d been part of them then my identity would be so tied up in my relationships to other people—what I was born into, tight & maintained family relations, never redefining myself or my history, never escaping childhood, but with a sense of self and belonging and continuity from youth to parenthood to old age. Imagine if you slept this close together:

    (and of course, relatives and friends would hear or even—gasp—see you having sex—but which is more normal, to hide it or display it?)

    ^ Apparently the Holocene (little ice age) is the reason NW European culture with its individualism and small family norms—which propagated the world over thanks (I guess) to guns, germs, and steel—changed that NW European culture from a practice of public sex (in the manor—like a barn, sleeping to private.
  • Would people be kinkier? Or maybe it would depend on the initial conditions (if sex-copying is like an Ising spin then perhaps the first mover (wink wink) decides whether the culture becomes kinky or not)….
  • Can you imagine flirting, teasing, when you’re young, and then seeing the one you wanted to be with have sex with the one you competed with? I can’t fathom what would happen next. Would it be easier to move on? Harder? Would things just be so different that I can’t even conceive it? (yuk yuk)
  • …And I won’t even go into the sexual norms of Babylon or Sparta
  • I can’t say which culture I would prefer to live in, because my preferences are a function of the way I was raised. Economists usually leave aside where utility hypersurfaces come from and just treat them as good (or at least, unimpeachable—or, at the very least, immalleable).
  • But from a deep-past, anthropological perspective like this, it’s easy to see, “Yeah, maybe I just think monogamy is good because, duh, I live in a monogamous culture”. More broadly, I live in a culture of monogamy, where crushes and attraction are repressed, where physical attraction should not be confused with “real love”, where you probably have never met your spouse yet when you’re 16, where what the family thinks of him/her is less important than what you think, where equality among the sexes is valued, where young people don’t date anymore, they just party and eventually have sex with their friends (except for certain religions where that subculture exerts a dominating influence or sometimes the subculture itself has been magnetised toward the prevailing culture), where ambition is good, where people want to be footballers, where monetary compensation is negotiated in secret and kept secret, where compensation is based on measurable individual achievement rather than arguable perceptions of morality, where shame and guilt are not uncommonly attached to sex, where people opine about who should have sex with whom and why and when and where and how, where people break up because they finish school and get a job in a different city, where classically sexual relationships are supposed to happen with one person over a lifetime but serial monogamy seems to be taking over, where people puff themselves up to impress strangers or newly-met friends-of-friends, especially when they’re afraid or ashamed of themselves on the inside.
  • I mean of course there are various arguments you could make (at least I’ve heard some) as to why monogamy is good, or why love as it’s conceived by us is the right way to conceive it, or why everybody having sex in public would be weird, or gross, and people in my culture argue back and forth both directions about these things—but at least for me, I really can’t extricate myself enough from the expectations and the learned behaviours and the way things have always worked for me and my expectations of others and … so on.
  • Things I take for granted. Anyway, back to private property

One of my least favourite aspects of modern capitalist life is the segregated non-interaction of private persons with each other and each other’s property.

  • Everyone lives in their own place—or cramp in with flatmates—they can at least be a network of friends, since the formula for friendship requires proximity and random encounters. That is, if you don’t work opposite hours….
  • Everyone rides the tube to work while not speaking to each other. Or goes running alone, listening to their own iPod’s, dreaming of a career success or thinness/sexiness and people liking them-which idea was implanted by yet another commercial interest….
  • Or outside major cities, everyone drives in their own car and listens to the radio by themselves. At least drivers who talk on their mobile phones are enjoying some person-to-person interaction.
  • Rich suburban people all have their own pool. (And if a neighbour drowns in it, it’s your fault—so better put up a fence.)

Things are too entangled, too complex, for me to state a preference. Although, I guess by staying where I am, I’m tacitly putting up with and agreeing to the norms I was raised by. Maybe I am being too pessimistic, or maybe someday I will seek out something new … or try to get together with people who want to make something new….

I would link this up to some other thoughts I’ve had about charity and need. In a clear sense, somebody who accepts charity (say thanking you for giving something that’s actually rather crappy but they won’t tell you that since they want to be polite) does something back for the giver; if we had an fMRI we could measure the utility upticks in the donor and if we knew all of the neurochemistry we could say which dopamines are flowing where.

That’s undeniably true but the first time someone pointed it out to me, it clashed with my simple and straightforward view that the rich giver is the one doing the good act and the poor receiver should be grateful. But human interactions are more complicated than that, clearly. And something similar could maybe be said of the ever-escalating wealth and comfort of our age—or at least how my culture chooses to make use of that wealth.









http://www.the-latest.com/files/rex-dance.jpg

girls with dirty dresses in kentucky 1960's

When people are poor they lean on each other, and maybe in reaching the goal of standing fine alone something else is therefore symplectically lost. We should call up some of the boomerang millennials and ask how their failure to fly out of the nest really turned out—if being a loser didn’t have its upsides in terms of strengthening familial relationships. And then I’ll ask myself what it is I’m aiming for.




Brains sound like a wicked-hard space to think about.
It’s a tightly connected (but not totally connected) network (graph theory)
Each of the nodes’ 3-D location may be important as well (voxels)
The signals propagate through time (dynamical)

Brains sound like a wicked-hard space to think about.

  • It’s a tightly connected (but not totally connected) network (graph theory)
  • Each of the nodes’ 3-D location may be important as well (voxels)
  • The signals propagate through time (dynamical)

hi-res




Local characteristic times are at least 1 millisecond, and the speed of propagation of the nervous influx is between 1 and 100 meters per second, so that times of O(100 milliseconds) are easily reached.