The science of imagination - Andrey Vyshedskiy

Prevodilac: Kristina Ivsic Lektor: Ivana Krivokuca

Imagine, for a second, a duck teaching a French class,

Zamislite, na sekund, patku koja drži čas francuskog,

a ping-pong match in orbit around a black hole,

ping-pong partiju u orbiti oko crne rupe,

delfina kako balansira ananas.

a dolphin balancing a pineapple.

You probably haven't actually seen any of these things,

Verovatno nikada niste zapravo videli nijednu od ovih stvari,

but you could imagine them instantly.

ali ste mogli odmah da ih zamislite.

How does your brain produce an image of something you've never seen?

Kako naš mozak može da proizvede sliku nečega što nikada nismo videli?

That may not seem hard,

To možda ne izgleda teško,

but that's only because we're so used to doing it.

ali samo zato što smo navikli da to radimo.

It turns out that this is actually a complex problem

Ispostavlja se da je ovo u stvari kompleksan problem

that requires sophisticated coordination inside your brain.

koji zahteva sofisticiranu koordinaciju unutar našeg mozga.

That's because to create these new, weird images,

Jer da bismo stvorili te nove, čudne slike,

your brain takes familiar pieces and assembles them in new ways,

mozak uzima poznate delove koje spaja na nove načine,

like a collage made from fragments of photos.

kao kolaž sastavljen od fragmenata slika.

The brain has to juggle a sea of thousands of electrical signals

Mozak mora da žonglira gomilom od hiljadu električnih signala,

getting them all to their destination at precisely the right time.

postavljajući ih na njihovu destinaciju u tačno određeno vreme.

When you look at an object,

Kada pogledate neki predmet,

thousands of neurons in your posterior cortex fire.

aktiviraju se hiljade neurona u vašem posteriornom korteksu.

These neurons encode various characteristics of the object:

Ovi neuroni kodiraju razne karakteristike predmeta:

spiky, fruit, brown, green, and yellow.

šiljato, voće, braon, zeleno i žuto.

This synchronous firing strengthens the connections between that set of neurons,

Sinhronizovano aktiviranje pojačava veze između tog skupa neurona,

linking them together into what's known as a neuronal ensemble,

povezujući ih u nešto što nazivamo neuronski ansambl,

u ovom slučaju, ansambl za ananas.

in this case the one for pineapple.

In neuroscience, this is called the Hebbian principle,

U neuronaukama, ovo se naziva Hebov princip -

neurons that fire together wire together.

neuroni koji se zajedno aktiviraju, zajedno se umrežavaju.

If you try to imagine a pineapple later,

Ako kasnije pokušate da zamislite ananas,

the whole ensemble will light up, assembling a complete mental image.

ceo ansambl će se aktivirati, stvarajući celokupnu mentalnu sliku.

Dolphins are encoded by a different neuronal ensemble.

Delfini su kodirani drugačijim neuronskim ansamblom.

Zapravo, svaki predmet koji ste videli

In fact, every object that you've seen

is encoded by a neuronal ensemble associated with it,

kodiran je neuronskim ansamblom koji se vezuje za njega,

the neurons wired together by that synchronized firing.

neuronima koji su zajedno umreženi tim sinhronizovanim aktiviranjem.

But this principle doesn't explain the infinite number of objects

Ali ovaj princip ne objašnjava beskonačan broj predmeta

that we can conjure up in our imaginations without ever seeing them.

koje možemo da prizovemo maštajući, a da ih prethodno nismo videli.

The neuronal ensemble for a dolphin balancing a pineapple doesn't exist.

Neuronski ansambl za delfina koji balansira ananas ne postoji.

So how come you can imagine it anyway?

Pa, kako ga možete onda ipak zamisliti?

One hypothesis, called the Mental Synthesis Theory,

Jedna hipoteza, zvana teorija mentalne sinteze,

says that, again, timing is key.

kaže da je vreme ključno.

Ako se neuronski ansambli za delfina i ananas

If the neuronal ensembles for the dolphin and pineapple

are activated at the same time,

aktiviraju u isto vreme,

we can perceive the two separate objects as a single image.

možemo da opazimo dva različita predmeta

kao jednu sliku.

But something in your brain has to coordinate that firing.

Ali nešto u našem mozgu mora da koordiniše to aktiviranje.

One plausible candidate is the prefrontal cortex,

Jedan verodostojan kandidat je prefrontalni korteks,

which is involved in all complex cognitive functions.

koji je uključen u sve kompleksne kognitivne funkcije.

Prefrontal cortex neurons are connected to the posterior cortex

Neuroni prefrontalnog korteksa su povezani sa posteriornim korteksom

by long, spindly cell extensions called neural fibers.

tankim i dugim ćelijskim produžetkom koji se naziva neuronsko vlakno.

The mental synthesis theory proposes that like a puppeteer pulling the strings,

Teorija mentalne sinteze predlaže da kao što lutkar vuče konce,

the prefrontal cortex neurons send electrical signals

neuroni prefrontalnog korteksa šalju električne signale

down these neural fibers

niz ova neuronska vlakna

to multiple ensembles in the posterior cortex.

do višeslojnih ansamblova u posteriornom korteksu.

This activates them in unison.

Ovo ih aktivira usklađeno.

If the neuronal ensembles are turned on at the same time,

Ako se neuronski ansambli aktiviraju u isto vreme,

you experience the composite image just as if you'd actually seen it.

dobijamo složenu sliku kao da smo je zapravo i videli.

This conscious purposeful synchronization

Ova svesna svrsishodna sinhronizacija

of different neuronal ensembles by the prefrontal cortex

neuronskih ansambala u prefrontalnom korteksu

is called mental synthesis.

naziva se mentalna sinteza.

Kako bi mentalna sinteza funkcionisala,

In order for mental sythesis to work,

signals would have to arrive at both neuronal ensembles at the same time.

signali bi morali da stižu na oba neuronska ansambla u isto vreme.

The problem is that some neurons

Problem je u tome što su neki neuroni

are much farther away from the prefrontal cortex than others.

mnogo udaljeniji od prefrontalnog korteksa nego drugi.

If the signals travel down both fibers at the same rate,

Ako signali putuju niz oba vlakna istom brzinom,

they'd arrive out of sync.

ne stižu u isto vreme.

Ne možemo promeniti dužinu veze.

You can't change the length of the connections,

but your brain, especially as it develops in childhood,

No, posebno jer se razvija u detinjstvu, naš mozak,

does have a way to change the conduction velocity.

ima način da promeni brzinu prenosa.

Neural fibers are wrapped in a fatty substance called myelin.

Neuronska vlakna su obmotana masnom supstancom koja se naziva mijelin.

Myelin is an insulator

Mijelin je izolator

and speeds up the electrical signals zipping down the nerve fiber.

i ubrzava električne signale koji jure niz nervno vlakno.

Some neural fibers have as many as 100 layers of myelin.

Neka neuronska vlakna imaju čak 100 slojeva mijelina.

Others only have a few.

Drugi imaju samo nekoliko.

And fibers with thicker layers of myelin

Vlakna sa debljim slojevima mijelina

can conduct signals 100 times faster or more

mogu da sprovode signale stotinu ili još više puta brže

than those with thinner ones.

od onih sa tanjim slojevima.

Some scientists now think that this difference in myelination

Neki naučnici sada veruju da ta razlika u mijelinizaciji

could be the key to uniform conduction time in the brain,

može biti ključna u ujednačavanju vremena provođenja u mozgu,

and consequently, to our mental synthesis ability.

a posledično i za našu sposobnost mentalne sinteze.

A lot of this myelination happens in childhood,

Veliki deo mijelinizacije se događa u detinjstvu,

so from an early age,

tako da od ranog uzrasta,

our vibrant imaginations may have a lot to do with building up brains

naša živopisna mašta može da ima dosta veze sa razvijanjem mozga

whose carefully myelinated connections

čije pažljivo mijelinizovane veze

can craft creative symphonies throughout our lives.

mogu da stvore kreativne simfonije tokom naših života.