What is consciousness? - Michael S. A. Graziano

Translator: Mateja Babič Reviewer: Klavdija Černilogar Dwyer

Here are two images of a house.

Tukaj sta dve sliki hiše.

There’s one obvious difference,

Obstaja ena očitna razlika,

but to this patient, P.S.,

ampak pacientki P.S.

they looked completely identical.

sta obe videti popolnoma enaki.

P.S. had suffered a stroke that damaged the right side of her brain,

P. S. je utrpela možgansko kap, ki je poškodovala desno stran njenih možganov,

leaving her unaware of everything on her left side.

zato se več ne zaveda ničesar na svoji levi strani.

But though she could discern no difference between the houses,

Toda čeprav med hišama ni opazila razlike,

when researchers asked her which she would prefer to live in,

je, ko so jo raziskovalci vprašali, v kateri bi raje živela,

she chose the house that wasn’t burning—

izbrala hišo, ki ne gori -

not once, but again and again.

– ne enkrat, ampak znova in znova.

P.S.’s brain was still processing information

Njeni možgani so še naprej obdelovali podatke

from her whole field of vision.

iz celotnega vidnega polja.

She could see both images

Videla je obe sliki,

and tell the difference between them,

zaznala razliko,

she just didn’t know it.

vendar ni vedela, zakaj.

If someone threw a ball at her left side,

Če bi ji kdo vrgel žogo na njeno levo stran,

she might duck.

bi se morda sklonila.

But she wouldn’t have any awareness of the ball,

Vendar se ne bi zavedala žoge

or any idea why she ducked.

ali tega, zakaj se je sklonila.

P.S.’s condition,

Stanje P.S.,

known as hemispatial neglect,

imenovano enostransko prostorsko zanemarjanje,

reveals an important distinction between the brain’s processing of information

razkriva pomembno razliko med možgansko obdelavo informacije

and our experience of that processing.

in našo izkušnjo te obdelave.

That experience is what we call consciousness.

Tej izkušnji pravimo zavest.

We are conscious of both the external world and our internal selves—

Zavedamo se zunanjega sveta in samih sebe,

we are aware of an image

podobe se zavedamo na enak način,

in much the same way we are aware of ourselves looking at an image,

kot se zavedamo tega, da gledamo to podobo

or our inner thoughts and emotions.

ali svojih misli in čustev.

But where does consciousness come from?

Toda od kod prihaja zavest?

Scientists, theologians, and philosophers

Znanstveniki, teologi in filozofi

have been trying to get to the bottom of this question for centuries—

že več stoletij poskušajo priti do dna temu vprašanju,

without reaching any consensus.

ne da bi dosegli kakršno koli soglasje.

One recent theory is that

Ena zadnjih teorij pravi,

consciousness is the brain’s imperfect picture of its own activity.

da je zavest nepopolna možganska slika lastne dejavnosti.

To understand this theory,

Da bi razumeli to teorijo,

it helps to have a clear idea

nam je v pomoč jasna predstava o pomembnem načinu,

of one important way the brain processes information from our senses.

kako možgani predelujejo informacije na podlagi naših čutov.

Based on sensory input,

Na osnovi čutnih zaznav

it builds models,

gradijo modele, ki se nenehno posodabljajo

which are continuously updating, simplified descriptions

in so poenostavljeni opisi

of objects and events in the world.

predmetov in dogodkov v svetu.

Everything we know is based on these models.

Vse, kar vemo, temelji na teh modelih.

They never capture every detail of the things they describe,

Nikoli ne zajamejo vseh podrobnosti stvari, ki jih opisujejo,

just enough for the brain to determine appropriate responses.

zajamejo samo toliko, da lahko možgani določijo ustrezne odzive.

For instance, one model built deep into the visual system

Na primer, model, vgrajen globoko v sistem vida,

codes white light as brightness without color.

kodira belo svetlobo kot svetlobo brez barve.

In reality,

V resnici pa bela svetloba

white light includes wavelengths

vključuje valovne dolžine,

that correspond to all the different colors we can see.

ki ustrezajo vsem različnim barvam, ki jih lahko vidimo.

Our perception of white light is wrong and oversimplified,

Naše dojemanje bele svetlobe je napačno in preveč poenostavljeno,

but good enough for us to function.

vendar dovolj dobro, da lahko delujemo.

Likewise, the brain’s model of the physical body

Prav tako možganski model fizičnega telesa

keeps track of the configuration of our limbs,

spremlja obliko naših okončin,

but not of individual cells or even muscles,

ne pa posameznih celic ali celo mišic,

because that level of information isn’t needed to plan movement.

saj ta raven informacij ni potrebna za načrtovanje gibanja.

If it didn’t have the model keeping track of the body’s size, shape,

Če možgani ne bi imeli modela, ki bi spremljal velikost in obliko telesa

and how it is moving at any moment,

ter kako se giblje v vsakem trenutku,

we would quickly injure ourselves.

bi se hitro poškodovali.

The brain also needs models of itself.

Možgani prav tako potrebujejo modele samih sebe.

For example,

Na primer,

the brain has the ability to pay attention to specific objects and events.

možgani so zmožni biti pozorni na določene objekte in dogodke.

It also controls that focus,

Nadzirajo tudi to osredotočenost

shifting it from one thing to another,

ter jo prenašajo z ene stvari na drugo,

internal and external,

notranjo in zunanjo,

according to our needs.

glede na naše potrebe.

Without the ability to direct our focus,

Brez možnosti nadzorovanja osredotočenosti

we wouldn’t be able to assess threats, finish a meal, or function at all.

ne bi mogli oceniti nevarnosti, pojesti obroka ali sploh delovati.

To control focus effectively,

Za natančen nadzor osredotočenosti

the brain has to construct a model of its own attention.

morajo možgani sestaviti model svoje zbranosti.

With 86 billion neurons constantly interacting with each other,

S 86 milijardami nevronov, ki neprestano vzajemno delujejo,

there’s no way the brain’s model of its own information processing

model v možganih, ki opisuje to obdelavo informacij,

can be perfectly self-descriptive.

ne more biti popolnoma natančen.

But like the model of the body,

Toda tako kot za model telesa

or our conception of white light,

ali našo idejo bele svetlobe

it doesn’t have to be.

ta popolnost ni potrebna.

Our certainty that we have a metaphysical, subjective experience

Naše prepričanje, da imamo metafizično subjektivno izkušnjo,

may come from one of the brain’s models,

lahko izvira iz enega izmed možganskih modelov,

a cut-corner description of what it means to process information

kar je skrčen opis za obdelovanje informacij

in a focused and deep manner.

na osredotočen in globok način.

Scientists have already begun trying to figure out

Znanstveniki že raziskujejo,

how the brain creates that self model.

kako možgani ustvarijo lasten model.

MRI studies are a promising avenue for pinpointing the networks involved.

Raziskave z uporabo magnetne resonance

so obetaven način za natančno določanje vpletenih omrežij.

These studies compare patterns of neural activation

Te raziskave primerjajo vzorce nevronskih aktivacij

when someone is and isn’t conscious of a sensory stimulus, like an image.

ob zavedanju in nezavedanju čutnih dražljajev, kot je slika.

The results show that the areas needed for visual processing

Rezultati kažejo, da se območja, potrebna za vizualno obdelavo,

are activated whether or not the participant is aware of the image,

aktivirajo ne glede na to, ali se oseba zaveda slike ali ne,

but a whole additional network lights up

vendar se celotna dodatna mreža prižge,

only when they are conscious of seeing the image.

kadar se slike zaveda.

Patients with hemispatial neglect, like P.S.,

Bolniki z enostranskim prostorskim zanemarjanjem,

kot je P.S., imajo ponavadi poškodbo na določenem delu omrežja.

typically have damage to one particular part of this network.

More extensive damage to the network can sometimes lead to a vegetative state,

Večja poškodba omrežja lahko včasih privede do vegetativnega stanja,

with no sign of consciousness.

brez znakov zavesti.

Evidence like this brings us closer to understanding

Dokazi, kot je ta, nam pomagajo bolje razumeti,

how consciousness is built into the brain,

kako je zavest vgrajena v možgane,

but there’s still much more to learn.

vendar se moramo še veliko naučiti.

For instance,

Na primer,

the way neurons in the networks related to consciousness

način, na katerega nevroni v omrežjih, povezanih z zavestjo,

compute specific pieces of information

izračunajo določene informacije,

is outside the scope of our current technology.

je izven dosega današnje tehnologije.

As we approach questions of consciousness with science,

S tem ko na vprašanja o zavesti odgovarjamo z znanostjo,

we’ll open new lines of inquiry into human identity.

odpiramo nove možnosti raziskovanja človeške identitete.