It's 4 a.m., and the big test is in eight hours, followed by a piano recital. You've been studying and playing for days, but you still don't feel ready for either. So, what can you do? Well, you can drink another cup of coffee and spend the next few hours cramming and practicing, but believe it or not, you might be better off closing the books, putting away the music, and going to sleep.
Četiri su sata ujutro i veliki je ispit za osam sati, uz koji moraš naučiti i recital. Učiš i sviraš već danima, ali i dalje se ne osjećaš spremno ni za jedno od toga. Pa što možeš učiniti? U redu, možeš popiti još jednu šalicu kave i provesti još nekoliko sati štrebajući i vježbajući, ali vjerovao ili ne, možda bi bilo bolje da zatvoriš knjige i odložiš instrument te odeš spavati.
Sleep occupies nearly a third of our lives, but many of us give surprisingly little attention and care to it. This neglect is often the result of a major misunderstanding. Sleep isn't lost time, or just a way to rest when all our important work is done. Instead, it's a critical function, during which your body balances and regulates its vital systems, affecting respiration and regulating everything from circulation to growth and immune response.
Spavanje zauzima gotovo trećinu naših života, ali mnogi od nas obraćaju začuđujuće malo pažnje i brige za to. Ovo zanemarivanje često je rezultat velikog nerazumijevanja. Spavanje nije gubitak vremena ili samo način odmora kad je sav naš bitan posao završen. Umjesto toga, ono je kritična funkcija tijekom koje naše tijelo uravnotežuje i regulira svoje vitalne sustave, utječući na disanje i regulirajući sve, počevši od cirkulacije do rasta i imunosnog odgovora.
That's great, but you can worry about all those things after this test, right? Well, not so fast. It turns out that sleep is also crucial for your brain, with a fifth of your body's circulatory blood being channeled to it as you drift off. And what goes on in your brain while you sleep is an intensely active period of restructuring that's crucial for how our memory works.
To je odlično, ali o tome se možeš brinuti nakon ovog ispita, nije li tako? Pa, ne tako brzo. Ispostavilo se da je spavanje također presudno za tvoj mozak s petinom krvi koja cirkulira tvojim tijelom, a usmjerava se prema mozgu kako toneš u san. I ono što se događa u tvome mozgu dok spavaš intenzivno je aktivan period obnove koja je presudna u tome na koji način funkcionira naše pamćenje.
At first glance, our ability to remember things doesn't seem very impressive at all. 19th century psychologist Herman Ebbinghaus demonstrated that we normally forget 40% of new material within the first twenty minutes, a phenomenon known as the forgetting curve.
Na prvi pogled, naša sposobnost pamćenja stvari ne čini se uopće pretjerano dojmljiva. Psiholog iz 19. stoljeća Herman Ebbinghaus dokazao je da normalno zaboravljamo 40% novih informacija unutar prvih dvadeset minuta, a taj je fenomen poznat kao krivulja zaboravljanja.
But this loss can be prevented through memory consolidation, the process by which information is moved from our fleeting short-term memory to our more durable long-term memory.
Ali ovaj gubitak može se spriječiti konsolidacijom pamćenja, procesom kojim se informacija prebacuje iz našeg prolaznog kratkoročnog pamćenja u trajnije dugoročno pamćenje.
This consolidation occurs with the help of a major part of the brain, known as the hippocampus. Its role in long-term memory formation was demonstrated in the 1950s by Brenda Milner in her research with a patient known as H.M. After having his hippocampus removed, H.M.'s ability to form new short-term memories was damaged, but he was able to learn physical tasks through repetition. Due to the removal of his hippocampus, H.M.'s ability to form long-term memories was also damaged. What this case revealed, among other things, was that the hippocampus was specifically involved in the consolidation of long-term declarative memory, such as the facts and concepts you need to remember for that test, rather than procedural memory, such as the finger movements you need to master for that recital.
Ova konsolidacija pojavljuje se uz pomoć bitnog dijela mozga poznatog kao hipokampus. Njegovu ulogu u dugoročnom pamćenju demonstrirala je 1950-ih Brenda Milner u svojem istraživanju s pacijentom poznatim kao H. M. Nakon što mu je odstranjen hipokampus, sposobnost H. M.-a da stvara kratkotrajna pamćenja je oštećena, ali mogao je naučiti fizičke zadatke ponavljanjem. Zbog odstranjenja njegova hipokampusa, sposobnost H. M.-a da stvara dugoročna pamćenja isto je bila oštećena. Ono što je ovaj slučaj otkrio, među ostalim, jest da je hipokampus posebno uključen u konsolidaciju dugoročnog deklarativnog pamćenja, kao što su činjenice i pojmovi koje moraš naučiti za ispit, za razliku od proceduralnog pamćenja, kao što su pokreti prstiju koje moraš savladati za taj recital.
Milner's findings, along with work by Eric Kandel in the 90's, have given us our current model of how this consolidation process works. Sensory data is initially transcribed and temporarily recorded in the neurons as short-term memory. From there, it travels to the hippocampus, which strengthens and enhances the neurons in that cortical area. Thanks to the phenomenon of neuroplasticity, new synaptic buds are formed, allowing new connections between neurons, and strengthening the neural network where the information will be returned as long-term memory.
Milnerini nalazi, zajedno s radom Erica Kandela iz 90-ih, pružili su nam trenutni model načina na koji proces konsolidacije radi. Senzorni podaci u početku se prepisuju i privremeno pohranjuju u neuronima kao kratkoročno pamćenje. Od toga, oni putuju do hipokampusa koji jača i povećava neurone u tom kortikalnom području. Zahvaljujući fenomenu neuroplastičnosti, stvaraju se novi sinaptički završeci omogućujući nove veze među neuronima i jačanje neuronske mreže gdje se informacija vraća u obliku dugoročnog pamćenja.
So why do we remember some things and not others? Well, there are a few ways to influence the extent and effectiveness of memory retention. For example, memories that are formed in times of heightened feeling, or even stress, will be better recorded due to the hippocampus' link with emotion. But one of the major factors contributing to memory consolidation is, you guessed it, a good night's sleep.
I, zašto onda pamtimo neke stvari, a druge ne? Pa, postoji nekoliko načina utjecanja na opseg i učinkovitost pamćenja. Na primjer, sjećanja stvorena u vrijeme pojačanih emocija ili pak stresa bit će bolje zapamćena zbog povezanosti hipokampusa i emocija. Ali jedan značajan faktor koji doprinosi konsolidaciji pamćenja je, pogađate, dobar noćni san.
Sleep is composed of four stages, the deepest of which are known as slow-wave sleep and rapid eye movement. EEG machines monitoring people during these stages have shown electrical impulses moving between the brainstem, hippocampus, thalamus, and cortex, which serve as relay stations of memory formation. And the different stages of sleep have been shown to help consolidate different types of memories.
Spavanje se sastoji od četiri faze, od kojih su najdublje poznate kao sporovalno spavanje i brzi pokreti očiju. EEG uređaj, prateći ljude tijekom ovih faza, pokazao je električne impulse koji se kreću između moždanog debla, hipokampusa, talamusa i korteksa, koji služe kao relejne stanice formacije pamćenja. I pokazalo se da različite faze sna pomažu konsolidaciji različitih tipova sjećanja.
During the non-REM slow-wave sleep, declarative memory is encoded into a temporary store in the anterior part of the hippocampus. Through a continuing dialogue between the cortex and hippocampus, it is then repeatedly reactivated, driving its gradual redistribution to long-term storage in the cortex. REM sleep, on the other hand, with its similarity to waking brain activity, is associated with the consolidation of procedural memory. So based on the studies, going to sleep three hours after memorizing your formulas and one hour after practicing your scales would be the most ideal.
Tijekom non-REM sporovalnog sna, deklarativno pamćenje enkodira se u trajno skladište u prednji dio hipokampusa. Kroz neprekidnu komunikaciju između korteksa i hipokampusa, tada se opetovano reaktivira, potičući njegovu postupnu preraspodjelu u dugoročno skladištenje u korteksu. REM faza sna, s druge strane, sa svojom sličnošću s fazom budnosti mozga, povezana je s konsolidacijom proceduralnog pamćenja. Tako na temelju istraživanja odlazak na spavanje tri sata nakon pamćenja svojih formula i jedan sat nakon vježbanja ljestvica bio bi idealan.
So hopefully you can see now that skimping on sleep not only harms your long-term health, but actually makes it less likely that you'll retain all that knowledge and practice from the previous night, all of which just goes to affirm the wisdom of the phrase, "Sleep on it." When you think about all the internal restructuring and forming of new connections that occurs while you slumber, you could even say that proper sleep will have you waking up every morning with a new and improved brain, ready to face the challenges ahead.
Pa nadajmo se da sada vidiš kako preskačući san ne samo da štetiš svome zdravlju, nego je također manje vjerojatno da ćeš zadržati to znanje i vježbe od prethodne noći, što sve potvrđuje mudrost fraze "Prespavaj!" Kad razmisliš o unutarnjoj obnovi i stvaranju novih veza koje se odvijaju dok drijemaš, možeš zaključiti da će te dobar san buditi svako jutro s novim i poboljšanim mozgom koji je spreman suočiti se s novim izazovima.