Charan Ranganath

Like I know how to get from here to, let's say if I walk here from my hotel, I can just rigidly follow that route back, right? And there's another more integrative way, which would be what's called a cognitive map, which would be kind of a sense of how everything relates to each other. And so there's lots of people who believe that these maps that we have in our head are isomorphic with the world.

Like I know how to get from here to, let's say if I walk here from my hotel, I can just rigidly follow that route back, right? And there's another more integrative way, which would be what's called a cognitive map, which would be kind of a sense of how everything relates to each other. And so there's lots of people who believe that these maps that we have in our head are isomorphic with the world.

Like I know how to get from here to, let's say if I walk here from my hotel, I can just rigidly follow that route back, right? And there's another more integrative way, which would be what's called a cognitive map, which would be kind of a sense of how everything relates to each other. And so there's lots of people who believe that these maps that we have in our head are isomorphic with the world.

They're like these literal coordinates that follow Euclidean space. And as you know, Euclidean mathematics is very constrained, right? And I think that we are actually much more generative in our maps of space so that we do have these bits and pieces. And we've got a small task. It's right now, not yet. We need to do some work on it for further analyses.

They're like these literal coordinates that follow Euclidean space. And as you know, Euclidean mathematics is very constrained, right? And I think that we are actually much more generative in our maps of space so that we do have these bits and pieces. And we've got a small task. It's right now, not yet. We need to do some work on it for further analyses.

They're like these literal coordinates that follow Euclidean space. And as you know, Euclidean mathematics is very constrained, right? And I think that we are actually much more generative in our maps of space so that we do have these bits and pieces. And we've got a small task. It's right now, not yet. We need to do some work on it for further analyses.

But one of the things we're looking at is these signals called ripples in the hippocampus, which are these bursts of activity that you see that are synchronized with areas in the neocortex, in the default network, actually. And so what we find is that those ripples seem to increase at navigationally important points when you're making a decision or when you reach a goal.

But one of the things we're looking at is these signals called ripples in the hippocampus, which are these bursts of activity that you see that are synchronized with areas in the neocortex, in the default network, actually. And so what we find is that those ripples seem to increase at navigationally important points when you're making a decision or when you reach a goal.

But one of the things we're looking at is these signals called ripples in the hippocampus, which are these bursts of activity that you see that are synchronized with areas in the neocortex, in the default network, actually. And so what we find is that those ripples seem to increase at navigationally important points when you're making a decision or when you reach a goal.

So this speaks to the emotion thing, right? Because if you have limited choices, if I'm walking down a street, I could really just get a mental map of the neighborhood with a more minimal kind of thing by just saying, here's the intersections and here's the directions I take to get in between them. And what we found in general in our MRI studies is that

So this speaks to the emotion thing, right? Because if you have limited choices, if I'm walking down a street, I could really just get a mental map of the neighborhood with a more minimal kind of thing by just saying, here's the intersections and here's the directions I take to get in between them. And what we found in general in our MRI studies is that

So this speaks to the emotion thing, right? Because if you have limited choices, if I'm walking down a street, I could really just get a mental map of the neighborhood with a more minimal kind of thing by just saying, here's the intersections and here's the directions I take to get in between them. And what we found in general in our MRI studies is that

Basically, the more people can reduce the problem, whether it's space or any kind of decision-making problem, the less the hippocampus encodes. It really is very economical towards the points of highest information content and value.

Basically, the more people can reduce the problem, whether it's space or any kind of decision-making problem, the less the hippocampus encodes. It really is very economical towards the points of highest information content and value.

Basically, the more people can reduce the problem, whether it's space or any kind of decision-making problem, the less the hippocampus encodes. It really is very economical towards the points of highest information content and value.

Yeah, so this is really interesting. There are these oscillations, right? So there's these waves that you basically see. And these waves are points of very high excitability and low excitability. And at least during, they happen actually during slow wave sleep too. So the deepest stages of sleep when you're just zonked out, right?

Yeah, so this is really interesting. There are these oscillations, right? So there's these waves that you basically see. And these waves are points of very high excitability and low excitability. And at least during, they happen actually during slow wave sleep too. So the deepest stages of sleep when you're just zonked out, right?

Yeah, so this is really interesting. There are these oscillations, right? So there's these waves that you basically see. And these waves are points of very high excitability and low excitability. And at least during, they happen actually during slow wave sleep too. So the deepest stages of sleep when you're just zonked out, right?

You see these very slow waves where it's like very excitable and then very unexcitable. It goes up and down. And on top of them, you'll see these little sharp wave ripples. And when there's a ripple in the hippocampus, you tend to see a sequence of cells that resemble a sequence of cells that fire when an animal is actually doing something. So it almost is like a little, people call it replay.

You see these very slow waves where it's like very excitable and then very unexcitable. It goes up and down. And on top of them, you'll see these little sharp wave ripples. And when there's a ripple in the hippocampus, you tend to see a sequence of cells that resemble a sequence of cells that fire when an animal is actually doing something. So it almost is like a little, people call it replay.