Why can’t I remember being a baby?

11:03Kristin Ohlson:Got it.

11:03Dana Suskind:And so that would tell us that they remember, you know, having seen it the first time. And so then we can ask, what was the brain doing the first time they saw that waterfall? Was the brain doing something that enabled them to later look differently? Is the brain forming that memory that later changes their looking behavior? And so that's where we found that the hippocampus was active during the initial viewing of the waterfall that they would later indicate to us that they remembered.

11:36Kristin Ohlson:You basically found that they did remember because they stared longer at the images they'd already seen. And you're getting this additional layer of evidence showing that the hippocampus, the part of the brain that, you know, researchers for a while thought maybe was not developed enough to function in early childhood. You're saying it is functioning. So does that mean the babies are forming memories?

11:58Dana Suskind:We are showing that they're able to form some memories. The hippocampus is capable of forming specific memories over a few minutes. But now we need to start doing the research that can get us at longer durations, that can get at more complex memories.

12:14Kristin Ohlson:So what do we think happens to those memories? If we think they're being formed, do they just get wiped? What's going on?

12:22Dana Suskind:We're born with most of our neurons that we'll have for the rest of our life. And a lot of development is pruning away connections between neurons. And what is interesting is the hippocampus is one brain region where neurogenesis or the formation of new neurons happens continuously. And it happens a lot in early infancy. It's as if, you know, you're in a forest and it becomes overgrown. And so you can't reach where you were before.

12:50Kristin Ohlson:Yeah, you can't find your way through it.

12:52Dana Suskind:Exactly. Exactly.

12:53Kristin Ohlson:So it's like because babies are learning so much about the world, like object permanence or how to walk or how to speak, they might just not be able to actually remember things because too much is happening.

13:05Dana Suskind:Yeah. I mean, I think that's like a key way that I'm thinking about this is that, you know, what is the point of infancy? To me, you're learning a lot of the general things. You're learning who your parents are. You're learning how to walk. You're learning language, things that co-occur or happen more frequently. A few years ago, our group published work looking at the hippocampus for a different type of memory, something we call statistical learning. That just means that like you remember kind of a sequence of events that happened. So an example in a baby's life might be a bedtime routine. You know, that reoccurring pattern is something that we think babies are really good at.

13:49Dana Suskind:And in our previous study, we found that babies as young as three months use the hippocampus for this kind of statistical learning, this learning of these patterns. It gets back to this question of like, what is the point of infancy? You know, it might be the case that the hippocampus prioritizes learning regularities in the environment, learning patterns. And then after a while, once it's got that foundation, then it can start working towards learning more specific things.

14:22Kristin Ohlson:The idea of your question, what's the point of infancy, is so interesting to me because it's as if we have to almost learn how to remember, if that makes sense. It's like we have to learn all these basic skills of how to perceive and get around the world. We have to understand, like, I don't know, looking at my kid and seeing him learn that his hands are his hands, you know? You have to learn those basic, basic things before maybe you can carve a path through the forest, to use your metaphor.

14:51Dana Suskind:Yeah. And I mean, this is what some of our theories are pointing towards, is that, you know, we're building the memory system in early life. In the science of development, we talk about sensitive periods. So you might be aware of the fact that babies and children learn language better than adults. We call childhood a sensitive period for language. And so there are these theories that maybe early life is a sensitive period for learning in general, that we're building up the system and that it's really responsive to how the environment allows you to kind of form this memory system.

15:28Kristin Ohlson:You know, one thing that this brings up for me, especially as the parent of a young child, is, you know, the fact that he probably is not going to have specific memories that last the rest of his life for a couple of years. You know, he'll have some vaguer feelings, I guess, that are not specific memories, like you're calling them. But what does that mean for this period? What does it mean for how much what I do for him matters?

16:01Dana Suskind:As a new parent of an also very young child, these are the thoughts that I think about as well. And it's actually what I'm studying in my postdoctoral work here at Columbia is what are parents doing in early life and how is that shaping their kids' memory and development? I mean, we know on the one hand, there's infantile amnesia. On the other hand, early experiences matter. If you grow up in, you know, circumstances that are unideal, that can have lasting impacts. And I think it comes down to, you know, this kind of specific versus general thing. Like, if you are providing daily enrichment and love for your child, they're learning, you know, I am safe.

16:52Dana Suskind:I am loved. These are the things that matter. And so I think that's comforting.

17:04Kristin Ohlson:Okay, but really, what should I do? I can love my kid, that's good. But what else should I be focusing on if he's just going to forget everything? I called up someone who studies childhood development to find out. And we'll get to that in a minute. Okay.

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18:56Yeah, remember addicts? Remember?

19:00Kristin Ohlson:Hey, hey, remember Ghostbusters? Oh, I did it.

19:04Tristan Yates:My name is Dana Susskind. I'm a professor of surgery and pediatrics at the University of Chicago, and I study early childhood development and the important role that parents and caregivers play.

19:18Kristin Ohlson:You started out, I believe, as a cochlear implant surgeon, and now you're working on childhood development. How did that happen? What's the connection there?

19:27Tristan Yates:Yeah. Well, it actually makes a whole lot of sense. So long ago, when I first started our pediatric cochlear implant program at the University of Chicago, I started implanting cute little kids who all looked like they had the same potential to thrive after implant surgery and found very quickly that I could implant two children who looked very much the same, who had parents who loved them equally with the same technology, but would have very different outcomes with one of them really thriving after surgery in terms of language learning and trajectories and others same time out would barely be able to communicate.

20:06Tristan Yates:And it was sort of that experience and seeing these huge differences in outcomes after the same surgery that led me into this incredible world of childhood development and the importance of the early years and the importance of parents.

20:23Tristan Yates:Humans come out with brains that are literally only one-third the size of adult brains. That's very different than any other species. And that's why we're basically completely helpless. It's why, you know, the puppy, you know, can start feeding itself pretty quickly and start walking, whereas the human infant is helpless because our brains in those first three years of life, 85 % of the physical brain is built during those periods of time. And a million new neural connections happen every second. And basically the environmental input, the input from parents and caregivers, every serve and return, every touch, every gaze literally is helping shape and strengthen the neural connections that happen in our brain.

21:06Tristan Yates:The brain isn't being just built for your child's vocabulary development or their literacy ability. It's building their social brain, their ability to relate and connect to the rest of the world. The relationships and the expectations for relationships are built in those early years.

21:28Kristin Ohlson:Tell me if this is maybe an oversimplification, but, you know, I'm a parent of a young son. He's a little over seven months old. And I feel like maybe what I'm doing when I'm raising him is I'm building the structure of his brain or I'm building like the architecture and all the other stuff, all the specific things are going to fill in all the rooms of the big building that we're constructing together. But he's not going to start filling those in with specific ideas or specific memories until later on in his development.

22:01Tristan Yates:The analogy you make is exactly right. I think of building the physical brain, sort of like if you were thinking about through a computer lens, I think about it as building the hardware, the firmware, the memory, the RAM.

22:18Tristan Yates:You know, I think of K-12 as really important, but I think of those as software updates.

22:23Kristin Ohlson:Right.

22:26Tristan Yates:But these early years are building that infrastructure. At the end of the day, it's your attachment with him. being the perfectly imperfect parent. And I want you to not to strive for perfection because the one thing that AI has shown us is that humans don't grow from perfection and frictionless existence. And so feel okay every time you misstep, misunderstand and repair, because that is for him building the understanding of I can be loved by another human who missteps but is able to repair, he is starting to understand how to expect to be treated. And that's why, you know, it's almost like you're building the relationship map for him that's going to allow him in the future to have expectations of how he's going to be treated and loved by an imperfect human.

23:20Tristan Yates:You know, building that strong bond, showering him with rich language, you know, that back and forth, looking at him as a conversational partner from day one.

23:29Kristin Ohlson:Yeah, it's interesting you brought up AI and friction. What do you think this idea of a more frictionless existence is going to start meaning for kids?

23:41Tristan Yates:Yeah, I mean, it's a lot. I mean, I had a book that just came out actually on this. It's called Human Raised. And really, that's a lot of the argument of the book that, you know, children learn from imperfect parenting through friction, through the productive struggle. And we're seeing that friction that we've always looked at as like sort of a bug in the system, like, oh, my gosh, I wish this was a more frictionless existence with the other humans in our world. What we're finding is that it is key for relationships development, learning to have relationships, and actually even learning. I mean, that's why writing an essay with an LLM, you don't remember it at the end of the day, because there is something about what happens in the brain that we've sort of discounted on the friction side of things.

24:30Tristan Yates:So I actually think in some ways friction should be the word of the year, and we need to embrace it a little bit more. I mean, we don't need to friction Max, but we do need to see the power of the friction.

24:42Kristin Ohlson:So it sounds like, you know, even if my son is going to forget all of this, I mean, maybe on a deep level, it'll stick with him. But I don't know. Should I still have a nice big, you know, one-year-old birthday party?

25:01Tristan Yates:Heck yes. Heck yes. Because you're doing it partially for you. And the grandparents, let's be clear. And those are wonderful moments that they do remember at some level. My son, who's now 20-something in medical school, he was obsessed with Thomas the Choo-Choo Train.

25:21Kristin Ohlson:Cinders and ashes.

25:24Tristan Yates:I still have the box of the Thomas the Choo-Choo Train. So, yes, he may not remember exactly that birthday party and the cake that I worked very hard on. But it's even fun to talk about it now in his 20s and his girlfriend laughing. So, yes, do enjoy every moment. Don't get obsessed like it's got everything has to be perfect. But, you know, it's those are memories for everyone.

25:57Kristin Ohlson:This episode was produced by Danielle Hewitt, editing from Avishai Artsy, fact checking from Melissa Hirsch. and engineering from Patrick Boyd and Christian Ayala. It originally ran on the Explain It To Me feed. That's Vox's Colin show. So if you want to hear more episodes trying to answer all your questions, check out Explain It To Me wherever you listen. If you have thoughts about Unexplainable, we'd love to hear from you. You can email us at unexplainable at vox.com or you can support the show by joining Vox and becoming a member. Just go to vox.com slash members. And if you signed up because of us, let us know.

26:34Kristin Ohlson:Unexplainable is part of the Vox Media Podcast Network, and we'll see you right back here next time.

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27:05Tristan Yates:I'm not giving up. I am selling the building.

27:10Kristin Ohlson:The final season of FX is the Bear.

27:14Dana Suskind:The restaurant is flooded.

27:17Kristin Ohlson:Everything's either going to be okay. No, stop! Or not. We are outgunned and we are outmanned. We have each other. FX is the Bear. The final season. All episodes now streaming on Disney+.