Consolidation

00:05 So Barb, it's interesting to me people often come up and say well "You're a heart surgeon, that must be really challenging" and I always pause for a minute and I think that you know in fact what was so challenging was when I started as a medical student and then in the early days of my residency. But I found that the more I work at it and the more I became involved, actually I felt things got easier, it became easier to learn new things. So, can you give us some insights as to what's happening in the brain and so an explanation for that. Peter, there is a really fascinating explanation for why that happens and why learning can get easier as you go further along. So let's get started. So, it's important to understand a little bit of Neural shorthand. This will make our understanding of later concepts a little easier. So the Neural shorthand I'm going to teach you relates to how neurons connect together. We know we've seen how that happens, the little button connects with the dendritic spine and that's how we have memories. But, it would be pretty complicated if we showed lots and lots of neurons all connecting together like this. So, an easier way of looking at things is to instead of each neuron have a dot and the connections between neurons are actually just lines. The more you practice and the stronger that connection, you make that line a little thicker.

01:58 So, this can represent very briefly some of the ideas of connected neurons that occur when you're remembering something. But this will allow us to understand a very important concept called consolidation. And consolidation is when your brain kind of takes all those connections and simplifies them and makes them more elegant. So, I'll give you an example with a concept known as plate tectonics.

02:35 This is that idea that originally the globe had one big land mass on it and gradually through the millennia those land mass has broke apart and seas formed and eventually we have the continents that we have today. So, the idea of plate tectonics is actually rather complex in that it's combining lots of different ideas. So, we know continent broke apart formed today's continents but this involves the idea of a plate which we know is also affiliated with food and water and also continents forming.

03:26 We've got rifts forming between the continents, volcanoes, mountains, lots of different concepts come together within this one idea of plate tectonics. Now, each of those concepts that I mentioned have little dot neuron representations.

03:48 When you combine them altogether, they are really quite a complicated mass.

03:56 So, what the brain does is when you're thinking about plate tectonics, at first you're kind of thinking "Okay well we've got a plate, it moves apart. So that means I don't need to worry about the idea of plates with food on them. I don't need to think about mountains and how cold they are or the kinds of grasses and trees that grow on mountains." In other words, each of those concepts that I mentioned has lots of affiliated ideas that aren't important when you come to the greater conception of plate tectonics. So, as you begin to understand the idea of plate tectonics better, your mind starts to simplify, get rid of extraneous connections.

04:50 And in the end, you're left only with the essence of the idea of plate tectonics.

04:57 So, this is consolidation. It's crystallizing into the ultimate essence of the idea.

05:05 Now it isn't just that you're taking away connections. Sometimes you might, for example, add connections and build out so that idea is related to other ideas.

05:20 So, ultimately in the brain what is happening is your working memory of course as you're thinking about a topic is sending information weakly to neocortex and strongly to Hip, the hippocampus. And only when the working memory relaxes can the hippocampus work with Neo, the neocortex, but when Hip is working with Neo is when that consolidation is taking place. Once something is very very well consolidated, you actually don't even need the hippocampus anymore. So, that's the great thing about a well-consolidated piece of information is you can access it directly with working memory without going through Hip. So, when is consolidation best? When can a brain do it most easily? Well, you're not using your working memory really much at all when you're sleeping. So, consolidation occurs most often during the time when you're sleeping. That's a time when certain connections are snipped away and others are added in. In fact, we can almost have this certain neuro bath of chemicals that seals certain dendritic spines into place so that we start to build a nice strong connection where we need it. So, during sleep taking some connections away, adding other ones, strengthening certain ones, this is all taking place and that of course is consolidation. Now, consolidation I've shown here through the declarative system, but of course it also takes place through the procedural system. Ultimately, when you are learning something new, when you first start it can seem really difficult and you might get, let's say you're learning a language.

07:39 As you're learning Spanish, for example, you might be first starting with present tense and so you kind of learn some of the present tense aspects then you learn some past tense then you learn some future tense. Those are all beginning to come together and form the beginning of a schema for your understanding or expertise in the Spanish language. So, let's say you've got those 3 main tenses in mind, you might then add the idea of the conditional tense and also other tenses, for example imperative. And along with those, you're also adding in vocabulary and interesting phrases and all of these are adding together to create this wonderful network in your brain of the Spanish language. But as you're learning, you notice you already created parts of what you need to know. So, once you've learned several tenses you kind of get the idea of tenses and it can be easier to add in yet another tense. So, in this way you're forming this wonderful complex network, the schema of information, and what's terrific about a schema, a well-established schema no matter what you're learning whether it's language or math or something to do with skateboarding, you'll find that the higher you go or the more you learn, the easier it becomes to learn more because you're already hanging it on neuro information that you have put in mind previously. So, consolidation and build a schema of expertise and that's the way to go. So Barb, what a great analogy once again. It makes it so understandable to me. People often say that as a physician you know you talk doctor speak and in a way really what we are doing is learning a language but we build our language with biochemistry and anatomy and physiology and pharmacology and then hone those parts of knowledge to build new skills and as you go through you become more comfortable speaking that language.

10:26 It is important when you communicate with patients not to use doctor speak but in terms of learning your skill and your craft and your profession, it really does get easier and now we know why and the strength of consolidating and then building on prior knowledge are really important concepts and I think can help students as they may feel daunted at the start but ultimately it does get easier to build on these concepts and go forward. So, thank you. Thank you Peter and all I know is when I get heart surgery I want you to be my surgeon. Very nice, thank you Barb.