I have a doppelganger. (Laughter) Dr. Gero is a brilliant but slightly mad scientist in the "Dragonball Z: Android Saga." If you look very carefully, you see that his skull has been replaced with a transparent Plexiglas dome so that the workings of his brain can be observed and also controlled with light. That's exactly what I do -- optical mind control.
Imam dvojnika. (Smijeh) Dr. Gero je briljantan, ali pomalo lud znanstvenik iz "Dragonball Z: Android Saga." Ako pozorno promotrite, vidjet ćete da je njegova lubanja zamijenjena kupolom od prozirnog pleksiglasa kako bi se rad njegovog mozga mogao promatrati i kontrolirati pomoću svjetlosti. To je upravo ono što i ja radim -- vizualna kontrola uma.
(Laughter)
(Smijeh)
But in contrast to my evil twin who lusts after world domination, my motives are not sinister. I control the brain in order to understand how it works. Now wait a minute, you may say, how can you go straight to controlling the brain without understanding it first? Isn't that putting the cart before the horse? Many neuroscientists agree with this view and think that understanding will come from more detailed observation and analysis. They say, "If we could record the activity of our neurons, we would understand the brain." But think for a moment what that means. Even if we could measure what every cell is doing at all times, we would still have to make sense of the recorded activity patterns, and that's so difficult, chances are we'll understand these patterns just as little as the brains that produce them.
Ali, za razliku od mog zlog blizanca koji žudi za dominacijom nad svijetom, ja nemam tako zlokobne motive. Kontroliram mozak da bih shvatio kako radi. "Čekaj malo", mogli biste reći, "kako odmah možeš prijeći na kontrolu mozga prije nego što si ga razumio u potpunosti? Nije li to trčanje pred rudo?" Mnogi neuroznanstvenici se slažu s ovim i smatraju da će razumijevanje proizaći iz detaljnog promatranja i analiza. Kažu: " Kada bismo mogli snimiti aktivnost neurona, razumjeli bismo mozak." Ali, razmislite na trenutak što to znači. Čak kada bismo mogli mjeriti što svaka stanica radi i dalje bismo morali dokučiti koji je smisao snimljenih uzoraka aktivnosti, a to je veoma teško i vjerojatnost da bismo to razumjeli je jednako malena kao i mozak koji proizvodi tu aktivnost.
Take a look at what brain activity might look like. In this simulation, each black dot is one nerve cell. The dot is visible whenever a cell fires an electrical impulse. There's 10,000 neurons here. So you're looking at roughly one percent of the brain of a cockroach. Your brains are about 100 million times more complicated. Somewhere, in a pattern like this, is you, your perceptions, your emotions, your memories, your plans for the future. But we don't know where, since we don't know how to read the pattern. We don't understand the code used by the brain. To make progress, we need to break the code. But how? An experienced code-breaker will tell you that in order to figure out what the symbols in a code mean, it's essential to be able to play with them, to rearrange them at will. So in this situation too, to decode the information contained in patterns like this, watching alone won't do. We need to rearrange the pattern. In other words, instead of recording the activity of neurons, we need to control it. It's not essential that we can control the activity of all neurons in the brain, just some. The more targeted our interventions, the better. And I'll show you in a moment how we can achieve the necessary precision.
Pogledajte kako izgleda aktivnost mozga. U ovoj simulaciji, svaka crna točkica je jedna živčana stanica. Točkica je vidljiva u trenutku kada stanica proizvodi električni impuls. Ovdje imamo 10.000 neurona. Pred vama je, ugrubo, jedan posto mozga žohara. Vaši mozgovi su otprilike 100 milijuna puta kompleksniji. Negdje, u uzorcima poput ovih, ste vi, vaše percepcije, vaše emocije, vaša sjećanja, vaši planovi za budućnost. Ali, ne znamo gdje točno jer još uvijek nismo dešifrirali uzorke. Ne znamo koji kod mozak koristi. Da bismo napredovali, moramo probiti kod. Ali kako? Svaki iskusan haker će vam reći da mora biti u mogućnosti igrati se sa simbolima koda, ispremještati ih po svojoj volji kako bi mogao shvatiti što koji simbol znači. U situaciji u kojoj se mi nalazimo, ako želimo dekodirati informacije sadržane u uzorcima poput ovih, pukim promatranjem nećemo puno postići. Moramo ispremještati uzorke. Drugim riječima, umjesto snimanja aktivnosti neurona, tu aktivnost moramo kontrolirati. Nije nužno kontrolirati aktivnost svih neurona u mozgu, nekoliko će biti dovoljno. Što su točnije usmjerene naše intervencije, to bolje. Za trenutak ću vam pokazati kako možemo postići tu potrebnu preciznost.
And since I'm realistic, rather than grandiose, I don't claim that the ability to control the function of the nervous system will at once unravel all its mysteries. But we'll certainly learn a lot. Now, I'm by no means the first person to realize how powerful a tool intervention is. The history of attempts to tinker with the function of the nervous system is long and illustrious. It dates back at least 200 years, to Galvani's famous experiments in the late 18th century and beyond. Galvani showed that a frog's legs twitched when he connected the lumbar nerve to a source of electrical current. This experiment revealed the first, and perhaps most fundamental, nugget of the neural code: that information is written in the form of electrical impulses. Galvani's approach of probing the nervous system with electrodes has remained state-of-the-art until today, despite a number of drawbacks. Sticking wires into the brain is obviously rather crude. It's hard to do in animals that run around, and there is a physical limit to the number of wires that can be inserted simultaneously.
Budući da sam više realističan, nego veličanstven, ne tvrdim da će nam mogućnost kontrole funkcije živčanog sustava razmrsiti sve misterije, ali sigurno ćemo puno naučiti. Dakle, ja osobno nikako nisam prva osoba koja je shvatila kako je intervencija na mozgu moćno oružje. Povijest pokušaja kopkanja po funkcijama živčanog sustava je veoma duga i slikovita. Stvar je stara najmanje 200 godina, Galvani je radio dobro poznate eksperimente krajem 18. stoljeća i poslije. Pokazao je kako noga žabe trza kada se slabinski živac spoji na izvor električnog napona. Ovaj eksperiment nam je otkrio prvu i, možda, najosnovniju tajnu koda živčanog sustava: da je informacija zapisana u obliku električnog impulsa. Galvanijev pristup ispitivanja živčanog sustava pomoću elektroda ostao je na snazi do danas, unatoč nekim nedostacima. Prikopčavanje žica na mozak je očigledno pomalo primitivno. Tako nešto je teško primijeniti na životinjama koje trče uokolo, a postoji i fizička granica broja žica koje mogu biti prikopčane istovremeno.
So around the turn of the last century, I started to think, "Wouldn't it be wonderful if one could take this logic and turn it upside down?" So instead of inserting a wire into one spot of the brain, re-engineer the brain itself so that some of its neural elements become responsive to diffusely broadcast signals such as a flash of light. Such an approach would literally, in a flash of light, overcome many of the obstacles to discovery. First, it's clearly a non-invasive, wireless form of communication. And second, just as in a radio broadcast, you can communicate with many receivers at once. You don't need to know where these receivers are, and it doesn't matter if these receivers move -- just think of the stereo in your car. It gets even better, for it turns out that we can fabricate the receivers out of materials that are encoded in DNA. So each nerve cell with the right genetic makeup will spontaneously produce a receiver that allows us to control its function. I hope you'll appreciate the beautiful simplicity of this concept. There's no high-tech gizmos here, just biology revealed through biology.
Na prijelazu u novo stoljeće, počeo sam razmišljati: "Ne bi li bilo prekrasno kada bi netko naglavačke preokrenuo vladajuću logiku?" Tako da umjesto umetanja žice u neku točku na mozgu, preuredimo sam mozak pa da neki od njegovih živčanih elemenata postanu osjetljivi na difuzno odaslane signale poput bljeska ili svjetla. Takav pristup bi, doslovno brzinom munje, savladao mnoge prepreke koje su se prepriječile na putu ka otkriću. Prvo, to je očigledno neinvazivan i bežičan način komunikacije. I drugo, baš kao kod radio emitiranja, možeš komunicirati s mnogo slušatelja u isto vrijeme -- ne moraš znati gdje se oni nalaze i nije bitno kreću li se -- samo pomislite na radio u svojem automobilu. Ali ni to nije sve, mogli bismo proizvoditi receptore iz materijala koji su kodirani u DNK. Svaka živčana stanica s pravim genetičkim make up-om bi spontano proizvela receptor koji bi nam dozvoljavao da kontroliramo njenu funkciju. Nadam se da cijenite prekrasnu jednostavnost ovog koncepta. Tu nema high-tech uređaja, samo čista biologija.
Now let's take a look at these miraculous receivers up close. As we zoom in on one of these purple neurons, we see that its outer membrane is studded with microscopic pores. Pores like these conduct electrical current and are responsible for all the communication in the nervous system. But these pores here are special. They are coupled to light receptors similar to the ones in your eyes. Whenever a flash of light hits the receptor, the pore opens, an electrical current is switched on, and the neuron fires electrical impulses. Because the light-activated pore is encoded in DNA, we can achieve incredible precision. This is because, although each cell in our bodies contains the same set of genes, different mixes of genes get turned on and off in different cells. You can exploit this to make sure that only some neurons contain our light-activated pore and others don't. So in this cartoon, the bluish white cell in the upper-left corner does not respond to light because it lacks the light-activated pore. The approach works so well that we can write purely artificial messages directly to the brain. In this example, each electrical impulse, each deflection on the trace, is caused by a brief pulse of light. And the approach, of course, also works in moving, behaving animals.
Bacimo sada pogled na te čudesne receptore izbliza. Ako zumiramo jedan od ovih ljubičastih neurona, možemo vidjeti da je njihova vanjska membrana okružena mikroskopskim porama. Te pore provode električni napon i odgovorne su za komunikaciju u živčanom sustavu. No, te pore su posebne jer su povezane sa svjetlosnim receptorima koji sliče onima u našim očima. Kada bljesak ili svjetlost pogodi receptor, pore se otvaraju, električni napon se uključi i neuron šalje električni signal. Činjenica da su svjetlošću aktivirane pore kodirane u DNK, omogućuje nam veliku preciznost. Iako svaka stanica našeg tijela sadrži isti set gena, drukčije mješavine gena se aktiviraju i deaktiviraju u različitim stanicama. Ovo možemo koristiti kako bismo bili sigurni da samo neki od neurona sadrže naše svjetlošću aktivirane pore. U ovoj animaciji, modro bijela stanica u gornjem lijevom kutu ne odgovara na svjetlost jer joj nedostaje svjetlošću aktivirana pora. Ovaj koncept djeluje tako dobro da čak možemo mozgu direktno slati umjetne naredbe. U ovom primjeru, svaki električni impuls, svaki otklon od putanje, uzrokovan je kratkotrajnim pulsirajućim svjetlom, a pristup djeluje i kod životinja koje se kreću.
This is the first ever such experiment, sort of the optical equivalent of Galvani's. It was done six or seven years ago by my then graduate student, Susana Lima. Susana had engineered the fruit fly on the left so that just two out of the 200,000 cells in its brain expressed the light-activated pore. You're familiar with these cells because they are the ones that frustrate you when you try to swat the fly. They trained the escape reflex that makes the fly jump into the air and fly away whenever you move your hand in position. And you can see here that the flash of light has exactly the same effect. The animal jumps, it spreads its wings, it vibrates them, but it can't actually take off because the fly is sandwiched between two glass plates. Now to make sure that this was no reaction of the fly to a flash it could see, Susana did a simple but brutally effective experiment. She cut the heads off of her flies. These headless bodies can live for about a day, but they don't do much. They just stand around and groom excessively. So it seems that the only trait that survives decapitation is vanity. (Laughter) Anyway, as you'll see in a moment, Susana was able to turn on the flight motor of what's the equivalent of the spinal cord of these flies and get some of the headless bodies to actually take off and fly away. They didn't get very far, obviously. Since we took these first steps, the field of optogenetics has exploded. And there are now hundreds of labs using these approaches.
Ovo je prvi eksperiment te vrste i na neki je način optički ekvivalent Galvanijevog. Izvela ga je moja nekadašnja studentica Susana Lima, prije šest ili sedam godina. Susana je projektirala voćnu mušicu slijeva tako da samo dvije od 200.000 stanica u njenom mozgu imaju ekspresiju pora aktiviranih svjetlošću. Upoznati ste s tim stanicama jer su to one koje vas frustriraju kad pokušavate zgnječiti mušicu. One su istrenirale refleks bijega koji djeluje tako da mušica skoči u zrak i odleti kad god vi pomičete ruku. Ovdje možete vidjeti da bljesak ima identičan učinak. Životinja poskoči, raširi krila, vibrira krilima, ali ne može poletjeti jer je zaglavljena između dvije staklene ploče. Sada, kako bi bila sigurna da ovo nije bila reakcija na svjetlost koju mušica vidi, Susana je izvela jednostavan, ali pomalo brutalan pokus. Odrubila je glave svojim mušicama. Dekapitirane mušice mogu živjeti otprilike jedan dan, ali ne mogu raditi puno toga, samo stoje i pretjerano se dotjeruju. Dakle, čini se da je taština jedina osobina koja uspijeva preživjeti odrubljivanje glave. (Smijeh) Kako god, za trenutak ćete vidjeti da je Susana uspjela uključiti motor za letenje u tzv. ekvivalentu kralješnične moždine ovih mušica i izazvati da neka od ovih bezglavih tijela mušica polete. Očito, nisu daleko stigle. Od kada smo mi poduzeli prve korake, optogenetika se strahovito razvila i sada postoje na stotine laboratorija koji primjenjuju ovaj pristup.
And we've come a long way since Galvani's and Susana's first successes in making animals twitch or jump. We can now actually interfere with their psychology in rather profound ways, as I'll show you in my last example, which is directed at a familiar question. Life is a string of choices creating a constant pressure to decide what to do next. We cope with this pressure by having brains, and within our brains, decision-making centers that I've called here the "Actor." The Actor implements a policy that takes into account the state of the environment and the context in which we operate. Our actions change the environment, or context, and these changes are then fed back into the decision loop.
Mnogo smo napredovali od Galvanija i Susane koji su uspjeli postići da životinje trzaju ili polete. Sada možemo inteferirati sa njihovom psihologijom na mnogo korisnih načina, što ću vam i pokazati u svom posljednjem primjeru, koji je povezan sa poznatim pitanjima. Život je niz izbora koji stvaraju stalan pritisak na sljedeću odluku koju ćemo donijeti. Nosimo se s tim pritiskom tako što imamo mozak koji je centar našeg odlučivanja i koji ja zovem "Glumac". Glumac provodi politiku koja uzima u obzir stanje okoliša i kontekst u kojem djelujemo. Naše djelovanje radi promjene u okolišu i kontekstu, a ove promjene su onda vraćaju u petlju odluke.
Now to put some neurobiological meat on this abstract model, we constructed a simple one-dimensional world for our favorite subject, fruit flies. Each chamber in these two vertical stacks contains one fly. The left and the right halves of the chamber are filled with two different odors, and a security camera watches as the flies pace up and down between them. Here's some such CCTV footage. Whenever a fly reaches the midpoint of the chamber where the two odor streams meet, it has to make a decision. It has to decide whether to turn around and stay in the same odor, or whether to cross the midline and try something new. These decisions are clearly a reflection of the Actor's policy. Now for an intelligent being like our fly, this policy is not written in stone but rather changes as the animal learns from experience. We can incorporate such an element of adaptive intelligence into our model by assuming that the fly's brain contains not only an Actor, but a different group of cells, a "Critic," that provides a running commentary on the Actor's choices. You can think of this nagging inner voice as sort of the brain's equivalent of the Catholic Church, if you're an Austrian like me, or the super-ego, if you're Freudian, or your mother, if you're Jewish.
Sada moramo dodati malo neurobiološkog mesa na ovaj kostur apstraktnog modela. Konstruirali smo jednostavni jednodimenzionalni svijet za naš omiljeni subjekt, voćne mušice. Svaka komora između dvije vertikalne pregrade sadrži jednu mušicu. Lijeva i desna polovica komore su ispunjene s dva različita mirisa. Sigurnosna kamera nam omogućuje da promatramo kako mušice hodaju amo-tamo po komori. Ovdje imamo jednu takvu CCTV snimku. Kada mušica dođe do sredine komore gdje se miješaju dva mirisa, mora odlučiti. Mora odlučiti hoće li se okrenuti i ostati u istoj polovici ili prijeći sredinu i probati nešto novo. Ove odluke su refleksija Glumčeve politike. Za pametno biće poput naše mušice, ova politika nije trajno zapisana u kamenu, već se mijenja kako životinja uči iz novih iskustava. Možemo ujediniti taj element prilagodljive inteligencije u naš model pretpostavljajući da mozak mušice ne sadrži samo Glumca, već i drukčiju skupinu stanica -- Kritičara koji osigurava komentar na Glumčeve odluke. Ovaj gunđajući unutarnji glas možete zamisliti kao neku vrstu ekvivalenta Katoličke Crkve, ako ste Austrijanci poput mene, super-ega ako ste frojdovac ili kao vašu majku ako ste Židov.
(Laughter)
(Smijeh)
Now obviously, the Critic is a key ingredient in what makes us intelligent. So we set out to identify the cells in the fly's brain that played the role of the Critic. And the logic of our experiment was simple. We thought if we could use our optical remote control to activate the cells of the Critic, we should be able, artificially, to nag the Actor into changing its policy. In other words, the fly should learn from mistakes that it thought it had made but, in reality, it had not made. So we bred flies whose brains were more or less randomly peppered with cells that were light addressable. And then we took these flies and allowed them to make choices. And whenever they made one of the two choices, chose one odor, in this case the blue one over the orange one, we switched on the lights. If the Critic was among the optically activated cells, the result of this intervention should be a change in policy. The fly should learn to avoid the optically reinforced odor.
Dakle očito da je Kritičar glavni sastojak koji nas čini inteligentnima. Odlučili smo identificirati stanice koje igraju ulogu Kritičara u mozgu mušice. Logika našeg eksperimenta je bila poprilično jednostavna -- kada bismo rabili optički daljinski prekidač za kontrolu aktivnosti stanica Kritičara, trebali bismo moći natjerati Glumca da promijeni svoju politiku. Drugim riječima, mušica treba učiti iz grešaka koje misli da je učinila, ali ih zapravo nije učinila. Parili smo mušice čiji mozak je bio manje ili više nasumično obasut stanicama koje su odgovarale na svjetlost, a onda smo tim mušicama dali da donose odluke. Kad god su one izabrale jedan od dva mirisa, u ovom slučaju plavi umjesto narančastog, mi bismo upalili svjetlo. Ako je Kritičar bio među optički podražljivim stanicama, rezultat ove intervencije bi trebalo biti mijenjanje politike -- mušica bi trebala naučiti izbjegavati optički pojačan miris.
Here's what happened in two instances: We're comparing two strains of flies, each of them having about 100 light-addressable cells in their brains, shown here in green on the left and on the right. What's common among these groups of cells is that they all produce the neurotransmitter dopamine. But the identities of the individual dopamine-producing neurons are clearly largely different on the left and on the right. Optically activating these hundred or so cells into two strains of flies has dramatically different consequences. If you look first at the behavior of the fly on the right, you can see that whenever it reaches the midpoint of the chamber where the two odors meet, it marches straight through, as it did before. Its behavior is completely unchanged. But the behavior of the fly on the left is very different. Whenever it comes up to the midpoint, it pauses, it carefully scans the odor interface as if it was sniffing out its environment, and then it turns around. This means that the policy that the Actor implements now includes an instruction to avoid the odor that's in the right half of the chamber. This means that the Critic must have spoken in that animal, and that the Critic must be contained among the dopamine-producing neurons on the left, but not among the dopamine producing neurons on the right.
Evo što se dogodilo u dva slučaja: uspoređivali smo dva soja mušica, a svaka od njih je imala otprilike 100 svjetlošću podražljivih stanica u mozgu -- to je ovo zeleno, na lijevoj i desnoj strani. Ove dvije grupe stanica imaju zajedničko svojstvo da proizvode neurotransmiter dopamin. Ali identitet zasebnih neurona koji luče dopamin je očigledno različit na lijevoj i desnoj strani. Svjetlosna aktivacija tih stotinu stanica u dva soja mušice ima dramatično različite posljedice. Ako prvo promotrimo ponašanje desne mušice, možemo vidjeti da uvijek kada dođe na sredinu komore gdje se dva mirisa spajaju, maršira ravno kroz komoru, baš kao što je činila i prije. Njezino ponašanje je ostalo nepromijenjeno. Ponašanje lijeve mušice je sasvim različito. Kada dođe na sredinu komore, ona stane i pažljivo promotri granicu kao da njuši okolinu i onda se okrene. Ovo znači da politika koju Glumac primjenjuje sada uključuje i uputu da se izbjegava miris na desnoj polovini komore. To znači da je u toj životinji progovorio Kritičar koji mora biti sadržan među neuronima koji proizvode dopamin na lijevoj, ali ne i među neuronima koji proizvode dopamin na desnoj strani.
Through many such experiments, we were able to narrow down the identity of the Critic to just 12 cells. These 12 cells, as shown here in green, send the output to a brain structure called the "mushroom body," which is shown here in gray. We know from our formal model that the brain structure at the receiving end of the Critic's commentary is the Actor. So this anatomy suggests that the mushroom bodies have something to do with action choice. Based on everything we know about the mushroom bodies, this makes perfect sense. In fact, it makes so much sense that we can construct an electronic toy circuit that simulates the behavior of the fly. In this electronic toy circuit, the mushroom body neurons are symbolized by the vertical bank of blue LEDs in the center of the board. These LED's are wired to sensors that detect the presence of odorous molecules in the air. Each odor activates a different combination of sensors, which in turn activates a different odor detector in the mushroom body. So the pilot in the cockpit of the fly, the Actor, can tell which odor is present simply by looking at which of the blue LEDs lights up.
Nakon mnogo ovakvih eksperimenata, suzili smo identitet Kritičara na samo 12 stanica. Tih 12 stanica, kao što možete vidjeti ovo zeleno, šalju izlazne informacije strukturi u mozgu koja se naziva "gljivasto tijelo" (Corpora pedunculata) koja je prikazana sivo. Iz prethodnog modela znamo da je Glumac izvršna struktura mozga nakon primanja Kritičarovog komentara. Anatomija nalaže da gljivasta tijela imaju neku ulogu u izboru pokreta. Ako uzmemo u obzir sve što znamo o gljivastim tijelima, ovo ima smisla. Zapravo, ovo toliko ima smisla da čak možemo izraditi električnu igračku koja simulira ponašanje mušice. Neuroni gljivastog tijela su simbolizirani okomitim nizom plavih LED dioda na sredini ploče. Te LED diode su prikopčane na senzore koji detektiraju prisutnost molekula mirisa u zraku. Svaki miris aktivira drugu kombinaciju senzora, a koja zauzvrat aktivira drugi detektor mirisa u gljivastom tijelu. Tako nam pilot u kokpitu mušice, Glumac, može reći koji je miris prisutan jednostavno gledajući koja od plavih LED dioda je upaljena.
What the Actor does with this information depends on its policy, which is stored in the strengths of the connection, between the odor detectors and the motors that power the fly's evasive actions. If the connection is weak, the motors will stay off and the fly will continue straight on its course. If the connection is strong, the motors will turn on and the fly will initiate a turn. Now consider a situation in which the motors stay off, the fly continues on its path and it suffers some painful consequence such as getting zapped. In a situation like this, we would expect the Critic to speak up and to tell the Actor to change its policy. We have created such a situation, artificially, by turning on the critic with a flash of light. That caused a strengthening of the connections between the currently active odor detector and the motors. So the next time the fly finds itself facing the same odor again, the connection is strong enough to turn on the motors and to trigger an evasive maneuver.
Što će Glumac učiniti s tim informacijama ovisi o njegovoj politici koja je pohranjena u jačini veze između detektora mirisa i motora koji mušici omogućuje kretanje. Ako je veza slaba, motor će ostati isključen i mušica će nastaviti svoju putanju ravno po komori. Ako je veza jaka, motor će se upaliti i mušica će se okrenuti na suprotnu stranu. Sada uzmimo u obzir situaciju kada motor ostaje isključen, mušica nastavlja ići svojim putem i doživljava neke bolne posljedice, na primjer smrt. U situaciji poput ove, očekujemo da će Kritičar progovoriti i reći Glumcu da promijeni politiku. Mi smo umjetno kreirali ovu situaciju, uključujući Kritičara pomoću bljeska svjetla. To je prouzrokovalo pojačavanje veze između trenutno aktivnog detektora mirisa i motora. Sljedeći put kada mušica bude u dodiru s istim mirisom, veza će biti dovoljno jaka da pokrene motor pomoću kojega će mušica izvesti manevar odstupanja.
I don't know about you, but I find it exhilarating to see how vague psychological notions evaporate and give rise to a physical, mechanistic understanding of the mind, even if it's the mind of the fly. This is one piece of good news. The other piece of good news, for a scientist at least, is that much remains to be discovered. In the experiments I told you about, we have lifted the identity of the Critic, but we still have no idea how the Critic does its job. Come to think of it, knowing when you're wrong without a teacher, or your mother, telling you, is a very hard problem. There are some ideas in computer science and in artificial intelligence as to how this might be done, but we still haven't solved a single example of how intelligent behavior springs from the physical interactions in living matter. I think we'll get there in the not too distant future.
Ne znam za vas, ali meni je prilično uzbudljivo gledati kako nejasni psihološki pojmovi isparavaju i predaju primat fizičkom, mehaničkom razumijevanju uma pa makar to bio i um mušice. Ovo je samo prva dobra vijest. Druga je, barem za znanstvenike, da ostaje još mnogo toga što treba biti otkriveno. U eksperimentima o kojima sam vam pričao, formirali smo identitet Kritičara, ali i dalje nemamo pojma kako on radi svoj posao. Razmislite malo o tome, dosta je teško znati da si u krivu, ako ti to netko, učiteljica ili majka, ne kaže. Postoje neke ideje u informatičkoj znanosti i umjetnoj inteligenciji kako je sve to moguće, ali zasad nismo riješili niti jedan primjer kako se inteligentno ponašanje aktivira iz fizičkih interakcija u živoj materiji. Mislim da ćemo do toga doći u bliskoj budućnosti.
Thank you.
Hvala.
(Applause)
(Pljesak)