Why can’t I remember being a baby?

0:01Support for Explain It To Me comes from Fetch Pet Insurance. Are you a pet owner? Every six seconds, a pet owner in the U.S. gets hit with a vet bill over$1 ,000. Always an unwelcome surprise. That's according to a study from a pet insurance company. That's where Fetch comes in. Fetch is the most complete pet insurance for dogs and cats, according to ConsumerAdvocate.org. You get paid back up to 90 % of vet bills at any vet in the U.S. and Canada with claims paid back in as little as two days. Go to FetchPet.com slash save right now for your free quote. That's FetchPet.com slash save.

0:46This podcast is supported by Anthropic, the public benefit corporation behind Claude. Everyone's got a hard question about AI. Your job, your kids, where it's going. Anthropic was built to surface those questions and share what it finds along the way. Because there's hope in hard questions. Ask yours at claude.ai slash Spotify and keep thinking. That's claude.ai slash Spotify.

1:17For a long, long time, I thought they were dreams. I wonder if it's actually a memory or is it something my brain made up? What is it that he's actually going to start remembering and when?

1:32What's your earliest memory? I have this super specific memory of looking at this wall that divided my parents' living room and their kitchen. And I had a crayon in my hand and my mom stepped away for just like a couple of seconds. and, you know, that urge just overcame me and I started drawing circles on the wall. And my mom must have heard me doing something after she stepped away because she ran back into the room and she goes, oh my God, stop, stop, stop, stop, stop. My earliest memory is being in a backpack carrier. I think on my mom's back or honestly maybe my dad's. I don't remember that part, but we grew up in a very outdoorsy family.

2:18I remember, honestly, just kind of like bouncing around up high and we're like in nature. My mom was trying to get us to eat clementines and I did not want that clementine. And I just kept peeling it and handing the pieces to my sister, my older sister, and just giggling my head off, thinking that I was getting one over my mom by handing these clementine pieces to my sister. My mom putting my cat Sunshine into my arms and him crawling up on my shoulders. I'm walking on a blanket in the yard, and under the blanket there was a bee's nest. I stepped on a bee stinger. I have this one weird memory that I don't know if it was a dream that I had, but it was like I was surrounded by a world, this gray or dark black and purpley almost goo.

3:11Think about like really dark lasagna. I don't know how to describe it. I was just like, yeah, it was so weird. Yeah, it was like floating in part of this world or something. I had this memory of being terrified when I was little because two of my siblings had tried to swim across this lake. It wasn't a really huge lake. And I have this memory of my mother standing on the beach, you know, the wind whipping her hair and her jacket, calling into the wind with my siblings out in the lake and the dam, you know, looming in the distance. But none of these memories were true. A few years back, Kristen Olsen had a kind of unsettling experience.

4:01She'd taken a trip with her family back to the cabin where they used to spend their summers when she was little. And as I got out of the car and started walking around the cabin, I realized you couldn't see the dam from the house. It was nowhere near the house. And so there were all these things that were just false memories. I realized later, you know, that whole image that I had of my mother standing on the beach calling, it looked an awful lot like my memory of Auntie M and the Wizard of Oz, with Auntie M calling into the tornado, trying to get Dorothy to come back. Kristen got so interested in memory that she ended up writing an article for Eon magazine.

4:43I learned that it's super slippery. You know, it's kind of quirky and weird what manages to lodge in somebody's mind. How do you feel about all of this stuff that you don't remember or either remember incorrectly? Like, is the memory necessary for the time to be important? You know, one of the scientists that I talked to, I asked her that. I said, well, you know, if something happens in our past and it's like a tree falling in the forest that nobody's around to see, does it really matter? Does it really matter if it happened, if we can't really remember it? And she said, you might not have the specific memory of what happened, but you have sort of a general feeling about being happy and being loved.

5:26And so I kind of feel like, you know, even if I can't remember specific moments that I had with my family when it was younger and my siblings were still living at home and we were all doing things together, that I still carry that impression of their love and their fun, the fun that they brought into my life and the fun that I guess I brought into their life. I still carry that impression very strongly. So after all of this, what is the thing you still want to find out? Like, what's the mystery of memory you want to know the answer to? Oh, I guess I'm just fascinated by what remains. Even though we can't remember a narrative and an incident, we have an impression that remains of those early things that happened to us.

6:19Why don't we remember things from our deep past? and even if we don't, what kind of impression have they made on us? That tapestry of our early life, you know, it's sort of fascinating to know how much of it persists even if we can't get at it. I'm Noam Hassenfeld, sitting in for JQ today. And I'm not really sure about my earliest memory. Maybe something with a stroller near a lawn. I think mittens might have been involved somehow. But the more I think about it, the more I wonder whether it's real. And recently, I've been thinking about this question a lot for a totally different reason.

7:09My wife and I just had our first kid. He's a little over seven months old. And when I'm sitting with him or making up games... I wonder, is he going to remember any of this? And does it matter?

7:31This week on Explained It To Me from Vox, why can't I remember being a baby? And what does that mean for how I should be a father?

7:52Support for Explain It To Me comes from Fetch Pet Insurance. Here's something that might surprise you. Every six seconds, a pet owner in the U.S. gets hit with a vet bill over$1 ,000. That's according to a study from a pet insurance company. Be prepared with Fetch Pet Insurance. Fetch is the most complete coverage for dogs and cats, according to ConsumerAdvocate.org. Fetch covers accidents, illnesses, diagnostics, and more. Every vet in the U.S. and Canada is in network. You can build a plan that fits your budget. And once approved, claims are paid back in as little as two days. To learn more, go to FetchPet.com slash save.

8:34That's FetchPet.com slash save.

8:43Support for the show comes from Whatnot. What's a thing you're passionate about that lights you up when someone asks you about it at a party? Whatever it is, WhatNot is the live shopping platform that can help you turn that passion into a business. Whether it's beauty, collectibles, electronics, luxury fashion, even cookies, sellers are building real, thriving businesses. Anyone can sell, whether your business is big, small, or yet to exist. People selling on WhatNot sell 10 times more than on any other marketplace. That's because you're not just listing products. You're building real connections with buyers.

9:20You go live, show off products in real time, and turn what you love into real income. WhatNot buyers spend more than an hour a day in the app. They're not just browsing. They're engaged, buying, and coming back. Our colleague Claire has tried WhatNot. Here's what she has to say. Shopping on the WhatNot app is just such a fun experience. There's a million different sellers. You can really find anything that you're looking for. And it's a lot of fun to win these auctions. It's a total adrenaline rush. Search Whatnot, W-H-A-T-N-O-T, in the App Store, download, and you can start selling right away.

10:01My kid is about nine and a half months old. And I'm like, you're not going to remember any of this. It's also fascinating how we have to study babies, even though we all literally went through these stages. And there's just so much that's not fully known. It's Explained It to Me. I'm Noam Hassenfelb. And we've been talking about our earliest memories. I first got into psychology because of an interest of who we are as people and how we came to be. And that starts with our earliest moments in childhood. Tristan Yates is a cognitive psychologist at Columbia University. It's fascinating that, you know, the early life is so foundational to who we are and who we become.

10:47And yet we can't recall specifically what happened in our earliest days. Tristan says scientists are still figuring out exactly why we don't remember our first few years of life. There's been a few, you know, different theories. So the one idea that we wanted to tackle in our research is that the brain system that's really important for specific memories is just not yet ready to form those specific memories in infancy. So this is a brain region called the hippocampus, and it takes a really long time to develop. So if you look at the structure of this brain region, it continues to develop well into adolescence.

11:27So the thought was it's just not yet able to store the specific memories that we would have in adulthood. And instead, we're having more kind of general memories in early infancy.

11:43Okay, so yeah, you did this study recently on this hypothesis. What'd you do? What'd you find? So we, in the lab of Nick Turk Brown at Yale, did an awake infant fMRI study. So that's using the MRI machine that you would normally do at a doctor's office, but kind of tweaking the parameters so we can look at brain function. People aren't doing this type of research because it's so hard to get a baby inside an MRI machine to sit still long enough for us to get those images. I mean, I just flew with my seven-month-old to Chicago, and that was extremely difficult. Like, how do you get a baby to sit still in an MRI?

12:26So we use the same MRI machine that you would use at a doctor's office. We just make it really child-friendly. So we have toys in the room. We use what's called a vacuum pillow to form like a baby taco around the baby. So they kind of move a little bit less. Baby taco. Yeah. And then one big innovation is we show pictures or movies to the babies right in front of them, right on top of a panoramic scene inside the MRI. So it's like baby IMAX. Baby IMAX. Yeah, exactly. Okay, that actually sounds much better than the MRIs that I have gotten done in my life. Yeah. Okay, so you got the babies in the baby IMAX, in the baby taco, and then what are you looking at?

13:19So for the particular study that we published last year on memory, We showed babies different images. And so the idea is that we wanted to know if they would look differently when they saw an image a second time. So we show them an image, another image, another image, another image. And then that first image we showed, let's say it was a waterfall. We're going to show it alongside a new image. And so now they have something that they've seen before alongside something they've never seen before. So if they have a memory for having seen the waterfall, then we think that they're going to look differently between these two images.

13:56Like staring longer or something like that? Exactly. So based on prior work, we think that they should stare longer at the thing that they've seen before. Got it. 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.

14:37You 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 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? 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.

15:14So what do we think happens to those memories? If we think they're being formed, do they just get wiped? What's going on? 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. Yeah, you can't find your way through it. Exactly.

15:53Exactly. 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. 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.

16:34That 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. 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.

17:23The 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. 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.

17:59In 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. 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.

18:47You 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? 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.

19:37And 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. I am loved. These are the things that matter. And so I think that's comforting.

20:05Okay, 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.

20:30Support for the show comes from Rippling. Imagine you just found your sales team is at risk of missing a quota. No need to panic. Just ask Rippling AI. Since it's built on your real-time people and business data, Rippling AI can pull metrics from Rippling and Salesforce into a meeting-ready dashboard showing quota attainment, hey-oh, headcount trajectory, hey-oh, and monthly revenue to quota by region, hey-oh. In seconds, you can see exactly what's behind your quota risk and fix it before it's missed. Question answered. Action taken. Crisis averted. Mic dropped. Ready to rule your business? Business rules.

21:13Head to rippling.ai slash explained to get the only AI built to give you full visibility and take complex actions across your entire organization. That's r-i-p-p-l-i-n-g dot a-i slash explained. Sign up for exclusive access today.

21:33This podcast is supported by Anthropic, the public benefit corporation behind Claude. Everyone's got a hard question about AI. Your job, your kids, where it's going. Anthropic was built to surface those questions and share what it finds along the way, because there's hope in hard questions. Ask yours at Claude.ai slash Spotify and keep thinking. That's claude.ai slash Spotify.

22:27half his life ago and kind of, I don't remember things from half my lifetime ago. And how I think that memory can live on through family anecdotes that we don't. We're back with Explain It To Me. 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. 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? Yeah. Well, it actually makes a whole lot of sense.

23:08So 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. 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.

24:00humans 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 percent 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, you know, every serve and return, every touch, every, you know, gaze literally is helping shape and strengthen the neural connections that happen in our brain.

24:44The 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 to and connect to the rest of the world. The relationships and the expectations for relationships are built in those early years.

25:06Tell 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. 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.