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Our Amazing but Flawed Memory

Dr. Biology:

This is Ask A Biologist a program about the living world and I'm Dr. Biology. Do you remember the first time you rode a bike or drove a car? Do you remember what color they were? Mine was a bright yellow 1974 Volkswagen Super Beetle. Maybe you put your memory to work recently studying for a test or used it when playing a card or a video game.

It turns out that remembering things either from a few minutes ago or the previous day and even years ago is an important part of how we live and learn. Just how memory works and at times doesn't work is the topic of this podcast.

To help us dig into our amazing but flawed memory is my guest, Whitney Hanson. She is a cognitive psychologist and principal lecturer in the Department of Psychology at Arizona State University, where she teaches a class called Memory in the Real World. She also consults on eyewitness memory and how it can be - well, let's say distorted for different reasons.

So, now let's jump in and find out just a bit about how and what we remember. And maybe we can also get a few tips to help us improve our memory. Whitney, thank you so much for taking time out to join me on Ask A Biologist.

Whitney:

Thank you. I'm very happy to be here.

Dr. Biology:

Before we dive into the well, tentatively, I'm calling this our fabulous memory with its flaws.

Whitney:

Mm hmm.

Dr. Biology:

I'd like to talk a little bit about memory in general. Let's start with what might seem obvious. What is short-term memory and when does memory shift from short-term memory to long-term memory?

Whitney:

Yeah. So, people often talk about memory as a unitary construct. It's one thing I have a good memory.  I have a bad memory. But actually, we know through scientific, evidence decades of research, that there's actually three different memory systems. You have sensory memory, which is exactly what it sounds like. Every one of your five senses has its own tiny little very, very short-term memory store.

Dr. Biology:

So, we're talking about seeing, hearing, touching.

Whitney:

Tasting.

Dr. Biology:

Tasting.

Whitney:

Smelling. 

Dr. Biology:

Smelling.

Whitney:

Yeah. Okay. And people often take this sensory memory for granted. But an example of that would be if you go see a movie if you go see a movie, a movie film is actually a bunch of pictures, but they're played quickly. But we don't perceive it as a picture, picture, picture picture. We perceive it as continuous movement.

That's because our visual sensory memory is filling in the blanks. It's holding that image from picture A active while. Picture B comes up. So, it feels like there's continuity between A and B, even though truly it is just a set of still images. So, sensory memory is very accurate but very short-term. And if you want to take something from sensory memory to what we call short-term memory or working memory, you really have to be paying attention to it.

So, for example, even right now, you're listening to me speak, you might be sitting down as you're listening to this podcast, you're probably not thinking about how your legs feel pressing against the chair but now that I mention it, you can sort of think, oh yeah, my legs are getting a little tired or I need to shift my weight. That signal was always there. Your skin was always picking up that sense of touch, but you weren't paying attention to it, and so you weren't going to encode it for short-term memory or long-term memory.

So, that's why you need attention. Attention and allows you to focus on the sensory sensations and transfer that information from sensory memory to short-term memory.

Dr. Biology:

So, when we talk about short-term memory, how long is short-term memory? [laughter]

Whitney:

Yeah, short-term memory really only lasts a few seconds. Sensory memory, we're talking milliseconds, so thousandth of a second maybe half a second. Short-term memory typically lasts a few seconds. It can last maybe a minute or two. But that requires some work on your part.

So, short-term memories are truly memories that are just sort of we're focused on it in the moment. And then when we stop focusing on it, it can go away unless you're able to create a long-term memory. So, you can transition information from sensory to short-term and then short-term to long-term. What's interesting about short-term memory, like I mentioned that we also call it working memory. So, working memory is the more modern term that is used in cognitive psychology because it really emphasizes what that storage system does. It's active. It's working. It is short-term. It only lasts for a few seconds, but it does so much more than just hold information in its veridical form for a few seconds.

When you are listening to someone talk, you're not memorizing every word they say verbatim. You're taking the key ideas of what they're saying. You're thinking about it in your mind. You're formulating the follow-up questions you want to ask. That is an active working process, and that's what working memory does. And working memory also pulls knowledge from long-term memory, which is the next system.

Dr. Biology:

First thing I've learned is short-term memory is much shorter than I thought.

Whitney:

Yeah.

Dr. Biology:

Long-term memory is a lot longer than I would have imagined. Are there different segments of long-term memory? Because there are some things I remember for the day. There are some things I will do well for a week or if I'm studying, I'm taking a class. I have to admit, there are times when I memorized and done really well on an exam, but if you asked me six months later how much of it I can remember that's a big difference.

Whitney:

Yeah. People think often that short-term memory lasts longer than it does. Like, what do you have for breakfast this morning? Often people think, Well, that's a short-term memory. If I asked you in a week, what did you have for breakfast on blah blah blah day, you're not going to remember. But that truly is a long-term memory.

You created a long-term memory of eating breakfast. I could ask you an hour later if you ate breakfast and what you had. If I ask you a month from now, you probably have a hard time remembering what you ate for breakfast. But that's not because it was a short-term memory. It's because it was a long-term memory that isn't really important. You haven't spent a lot of time since then thinking about what did I eat for breakfast on a particular day?

And that's what happens. Like, for example, about school work you remember the information well when you're taking the class the following semester, if you haven't thought about that information for months, it might feel like it's disappeared. But it really hasn't disappeared. It's still probably in your long-term memory somewhere. The problem is you just need some help getting it back out.

Dr. Biology:

For those ones that I need help, and even if I get help, I can't get them back. What causes long-term memory to fade or to become more difficult to remember?

Whitney:

You kind of want to think about memory. Like you might think about any sort of athletic training. The more you use it, the easier it's going to be. So, if you retrieve, for example, your password, maybe you use a password for email and you actually have to log in every single day. That long-term memory is going to be very solid. It's going to be very easy for you to retrieve. But what if you create a password and then you store it, right?

Like your browser stores it, your phone stores it, so you don't have to plug in that password for six months, then you get a new device. You have to plug in the password. You have no idea what it is. It's because you didn't practice it that it sort of has faded. But then let's say you wrote down the password or you have it stored and you can see it. When you see the password, you probably will have an inkling of recollection, like, oh yeah, I do remember that's the password I used. So, it was always there. And you've got that familiarity. And in fact, if you had to learn that password again, you would be faster to learn it the second time.

Same thing with academics, right? If you took a class and you feel like, oh, I don't remember anything from that math class. But then you take a class and it reviews the material, you'll be faster to learn it the second time. It'll be easier the second time. Why? Because there's still a trace of that long-term memory somewhere in there. The problem was you just couldn't get it out before, but now with practice, you're going to get it out.

Dr. Biology:

So, are there techniques for getting better other than the athletic idea? You know, if I keep using it, it's like a language. If you don't use a language, you're not good at it. So, a lot of people that learn a second language, this is a challenge if they don't keep practicing. Is there something you can do that you can help yourself retrieve things that are in the brain, but you're not being able to pull it out?

Whitney:

The tips that I would give about that really have to do with how memory works generally. So, when you're trying to create a long-term memory, there's a process of encoding or storing the memory. And then the second process is retrieving, getting it back out. So, I like to use the metaphor of whatever piece of knowledge.

Think of it as like a house in a city and you need to get to that house, right? So how are you going to get to that house? Well, a road. So, we want to think about these retrieval paths, kind of like roads. So, if you want to find that house, later on, a week later, a year later, one, you need to build a good road in the first place. So, that's how you encoded the information. And there's lots of evidence what we can do to encode well. But then you have to be able to get to that house later. And having a strong road is not sufficient.

So, this is why you need to maintain your roads. You need to keep them healthy and that is where the practice comes in practice retrieving. And then the final thing I would say is have lots of roads that all get to the same spot, right? If a road gets blocked or it's damaged, you're not going to be able to get to that house. But if you've got another option to get in there, it's going to be easier to access that house or access that information. So, you want to encode the information in a good way. You want to have lots of different paths that will get you to that information. Or different cues. And then you just want to practice.

Dr. Biology:

The lots of different paths. Reminds me of something else. We often hear people say and actually we experience, and that's motor memory, for example, dialing a number.

Whitney:

Mm hmm.

Dr. Biology:

Sometimes the number is not quite there. But if you get your finger going, all of a sudden, it's like, oh, yeah, it's, you know, 832279 

Whitney:

Exactly.

Dr. Biology:

So, is that two paths?

Whitney:

Yeah.

Dr. Biology:

Two ways of doing it?

Whitney:

Exactly. You've got the memory of the numbers, which would be more of like a verbal encoding 6321. But then you've also got the visual image, the pattern that can help you there as well. And that actually leads to a good way to remember information which is called the memory palace.

Dr. Biology:

Yes. And for the academics out there that when they say - method of loci [low-ki].

Dr. Biology:

Yeah.

Dr. Biology:

As in location.

Whitney:

Yeah.

Dr. Biology:

Yeah. Well, let's talk about memory palaces.

Whitney:

Yeah. So, our memory for visual information is quite good. In many studies, it seems like our memory for visual images and information is far better than our memory for verbal labels and cues. Certainly, the combination of both, if you can have a verbal label and a visual label, multiple pathways, that's going to be the best. But all other things equal, our memory for visual items seems to be better than our memory for verbal items.

And so if you're trying to remember, for example, a list of items to get at the grocery store. What you might want to do is think about those items visually. And a good way to organize that is to think about a place that you know really well. So, it's called the Memory Palace, but it doesn't have to be a palace. It can be your apartment, it can be your office, it could be a park that you really enjoy, but a place that you already know pretty well. And the idea is that you visualize that place, and then you would add in the items that you need at the grocery store all around that place. When you get to the grocery store, you remember that you go back to that visualization and you try to walk through your memory palace, and those objects should be there and act as cues for what you need.

So, for example, you might imagine like your front door, maybe you need toilet paper, and you imagine your front door and a big stack of toilet paper right when you walk in, you're going to trip over it. The more detailed you can be, the more creative you can be, the easier it's going to be to remember. So, a big stack of toilet paper that you almost trip over is going to be easier to remember than just like one roll of toilet paper.

Dr. Biology:

Is it better than if I said, I'm going to go into the bathroom in my house?

Whitney:

That'll be fine too. If you let's say if the bathroom is close to the front of your house and you just imagine yourself again, try to add in some silly details, like, oh, I've really got to go to the bathroom. I'm going to run straight to the bathroom, toilet paper. I also need toothpaste. I'm to imagine, you know, myself brushing my teeth. Then maybe you need milk. So, imagine yourself going out of the bathroom, walking to the kitchen. Again, you can imagine yourself opening the refrigerator, pulling out the milk, or if you can make it a little bit more interesting, a little bit more creative, maybe the milk is sitting on the counter and it's spilled onto the floor. But that'll be your cue to remember milk.

So, then you go to the grocery store when you walk in the grocery store, you imagine yourself, what was I doing? Oh, yeah, I had to run to the bathroom, get toilet paper, stopped to brush my teeth, went to the kitchen, there was milk spilling everywhere so what are the three things I need? Toilet paper, toothpaste, milk.

Dr. Biology:

Perfect. Hmm.

Whitney:

So, I actually have a little demonstration I can do. We can do a little memory test on the podcast to sort of illustrate this point. OK, so I am going to read you some letters. All you have to do is try to memorize the letters in the correct order, OK? And I'll try to read them about one per second at a consistent pace.

Whitney:

OK, here we go. A, G, N, O, M, I, C, A, B.

Dr. Biology:

So, I got A, G, O, M, I, C, B, was that right?

Whitney:

Pretty close. You got A, G. You missed N. O, M, I, C, and then A, B. So, yeah, you did pretty good. I think you got six of them.

Dr. Biology:

OK, well, how are we going to make it even easier?

Whitney:

So, I'm going to read you again a list of letters. And again, I want you to try to remember them. OK? I'm going to change up my pacing a little bit this time, though. OK, here we go - N, B, A - O, M, G - C, I, A - okay.

Dr. Biology:

N, B, A - O, M, G - C, I, A.

Whitney:

Yeah. So, you got all nine letters, right? There were nine letters the first time you didn't get them all the second time, you got them all. And it seemed like it was pretty easy. Did it feel easy?

Dr. Biology:

Much easier.

Whitney:

And why do you think that was?

Dr. Biology:

You did a good job of basically chunking them into little compartments so I could actually put them in my memory with meaning. Yeah. It wasn't just a random letter. I had sets, so - NBA National Basketball Association.

Whitney:

Yeah.

Dr. Biology:

And then we have. Oh my God, yeah.

Whitney:

OMG.

Dr. Biology:

Yeah. And then CIA.

Whitney:

Yeah. So, you mentioned two different things there that are both helping your memory. One is the chunking, putting things together instead of nine separate letters there were three chunks. Each chunk had three letters. And chunking truly is helpful. That's why phone numbers are organized the way that they are, right? With an area code that's three and then the first three and then the last four. That pause that you put in between a phone number, right? 4808675309. That pause is creating a chunk.

And I tried to do that when I read it. I put pauses in there to encourage you to create a chunk. But you also mentioned that these letters weren't random - NBA. So, you have a long-term memory of what NBA means. It means National Basketball Association. People in other countries may think of NBA as a random string of letters. It's not meaningful to them. OMG, right? If you're someone who texts that a lot, or uses it on social media, that's going to be easy to remember. CIA, some of your listeners may not be familiar with CIA if they're a little bit younger - Central Intelligence Agency. But older listeners will understand that.

So, it's a combination it's chunking to make things more manageable, but it's also pulling from long-term memory. And this memory test that I just gave you, this is an example of a working memory or a short-term memory test. And what we see is that by chunking and by pulling from long-term memory, people are actually able to expand the capacity of their short-term memory. Normally we can only remember seven plus or -2 items. So, anywhere from five to nine, which is about what you did on your memory test. But it's seven plus or -2 chunks. And so, if those chunks have ten items each, think about how you can expand your capacity. So, that can help your short-term memory, but also organizing things, linking it to previous knowledge that can also help your long-term memory as well.

Dr. Biology:

When you were talking about the memory palace, there are actually competitions out there.

Whitney:

Yeah.

Dr. Biology:

And they're pretty amazing.

Whitney:

Incredible. Yes.

Dr. Biology:

All right, so these are great tips. Is this something that someone should just go ahead and work on practicing? Is there an easy way to do it other than just saying OK, I'm just going to start putting things together in chunks and in ways that I can remember them? Is there a process that people can use to help remember things?

Whitney:

Well, again, I think it really depends on what you're trying to remember. If you're trying to remember someone's name that you just met, the first thing you need to do is pay attention. And that's really hard when someone introduces themselves. We sort of get in a habit of barely listening to their name and just thinking about what we're going to say. So, really pay attention. That'll help get the information into short-term memory.

Then if you want to get it into long-term memory, what you'd want to do is link it to some previous knowledge that you have. So, if someone introduces themself as Janice, you might think, Do I know a Janice? Does that remind me of anything? Maybe you think of Friends and the character Janice on Friends. Again, the more creative you can be, the more likely it is to stick. And it doesn't have to be like this name reminds me of another person I know.

For example, I had a student in a class once and I just always got his name wrong and his name was Jarvis. And so what I did was I pictured him holding a jar with a fish in it. Now, his name was not jar fish, but every time I saw him holding that, I remembered Jarvis. And to this day, if I saw that student, I would remember his name because it was so memorable. So, that's one thing for if you're trying to remember a name.

If you're trying to remember content for like a course, again, these same tricks can be useful, really engage with the material, try to organize it, try to link it to other knowledge that you have, link it to examples in your own life. Those will be much easier to remember.

Dr. Biology:

There are also mnemonics that people will use.

Whitney:

Yes, like Roy GI Bev, everyone learns that one for the color spectrum. Those can be very helpful as well. Or please excuse my dear Aunt Sally for order of operations. Those can be very useful. There's another system that's pretty useful called the PEG System, and with the PEG system, this can be really good for remembering like lists of items. You start by having a peg.

Whitney:

So, like one is bun, two is shoe, three is tree four is door. So, you do that for the ten items and you got to practice a little bit to get those down. But it's a little easy because they rhyme one button, two shoe. Then if you have to go somewhere you have to do something.

Maybe you are going to the grocery store, you have a peg that you can hang your items on. So, one is bun. All right, maybe I need to buy hamburgers. OK, that's easy. A bun for a hamburger. Two is shoe. Maybe the second thing I need is milk. Well, how am I going to link shoe to milk? So, this is where are you going to get a little bit creative? Maybe you imagine yourself dropping a gallon of milk and kicking it with your shoe. Again, the weirder it is, the more likely it is to stand out. Three is tree. Maybe you need laundry soap so you imagine clothes hanging in a tree. So, that's another way that can be really useful.

Dr. Biology:

Hmm. Well, we've been talking a lot about memory, and one of the things I think we all know is it's not perfect. It's flawed. And you have expertise with eyewitness testimony.

Whitney:

Mm hmm.

Dr. Biology:

Can we talk a little bit about how our memory can fail us and even trick us?

Whitney:

Yeah. So, we all know that this happens. This has happened to all of us where we've misremembered, where we parked our car, or we know we studied that term, but I just can't remember it on the day of the test. But in the case of eyewitness identification, the consequences of a memory error can be really severe. But it's the same principles that are causing us to misremember where we parked our car or failed to retrieve that important definition on a test.

It's those same ideas that are impacting the eyewitnesses memory as well. And this happens because we know that memory is not perfect. It's not like you record an event and then you just replay that videotape. Memory is reconstructive. So, when you are putting together a long-term memory, as I mentioned, you're pulling pieces, you're retrieving pieces, you're trying to drive down that road and find that house. And then bring that information to bear so you can use it. The problem is that, you know, it can be easy to go down the wrong road or along the way. Some of the details can decay or fade or you can pull the wrong detail. And so, when we reconstruct a memory, we can either omit details or we can add in details that weren't there.

And again, this is where things like our biases or our previous beliefs or experiences can come in and impact us. So, I'll give an example. The original example of this was done in a laboratory in the 1970s. So, about 50 years ago was when Dr. Elizabeth Loftus and colleagues started studying eyewitness memory in a scientific way. And in their first study, they had participants watch a video of a car accident, and then they asked them questions about what happened in the accident. Exactly like you would if you were an eyewitness observing this car accident.

One of the questions that they were asked was how fast was the car going when it hit the other car? Some participants heard that word hit. Some were asked how fast was the car going when it bumped the other car. Other participants were asked how fast was the car going when it smashed the other car. So, notice the verb is different. Hit, bumped smashed. They all saw the same video. So, you would expect their estimates of speed to be approximately the same, but they weren't. If you had to guess which group do you think gave the highest estimates of speed?

 Dr. Biology:

Probably smashed.

Whitney:

Smashed, right. Because you have previous knowledge. What does Smashed mean? Smash implies violence That implies speed. That implies broken glass. People are hurt. Right. So, it's just one word. It's just the word smashed. But smashed, if you are an English speaker, you know that word smashed. You know what it implies. And all that previous knowledge then impacts your reconstruction of the memory. And sure enough, those people in the smashed group remembered the speed about ten miles an hour faster than the other groups.

Dr. Biology:

Interesting. Especially when you said hit, bumped, bumped it was like, you know, it's like nudge.

Whitney:

Yeah. [laughter]

Dr. Biology:

You nudged the car as they went along.

Whitney:

Well, exactly. And so as the verb became less violent, the speeds were slower. Bumped, contacted, hit.

Dr. Biology:

All right. So, we've talked about memory. We've talked about its flaws. The things to do to get a better memory. We haven't really talked about where the memories are in our brain.

Whitney:

Yeah. Memories are stored in different places all throughout the brain. And different types of memories are stored in different areas. So, working memory really relies on the frontal lobe, but long-term memories. The hippocampus is critical. So, the hippocampus is kind of the C shaped structure that's right in the center of your brain. Just a little bit above the thalamus and the brainstem.

But we know the hippocampus is critical in your ability to create long-term memories. Because unfortunately, there are people who have had damage to their hippocampi, and they can no longer create new memories. So, remember how we talked about what you ate for breakfast this morning? Everyone thinks that that's a short-term memory. We know it's a long-term memory because of people like H.M. H.M., which stands for Henry Molaison. He had his hippocampi removed intentionally to help with his seizures. The great news was it helped his seizures, but the bad news was he could no longer create new long-term memories.

So, he could never remember if he ate breakfast that day. If you introduced yourself to him on a Monday, he would say, hi, nice to meet you. Tuesday. He would have no idea who you were. And so that's part of the reason that we know what you eat for breakfast is a long-term memory, not a short-term memory, because people like H.M. and others can never create those memories. But you and I can.

So, we know the hippocampus is critical for creating long-term memories, but the hippocampus is not the place where memories are stored forever. After a while, those long-term memories actually transfer to different parts of your cortex, which is the outer bark of your brain. So, after a while, a long-term memory, like what was the name of your grandmother that's not stored in the hippocampus? If your hippocampus was damaged, you could still remember the name of your grandmother. Because it moves to a different part of the brain after a while.

Dr. Biology:

So, is this why some dementia patients are good at really old memories?

Whitney:

Yes.

Dr. Biology:

And ones that are much newer, they just don't do well. So, there's the damage was probably in the hippocampus.

Whitney:

It starts in the hippocampus. So, someone with Alzheimer's disease, the damage, the decay starts in the hippocampus, which is why they lose the ability to remember, did I take my medicine? Where did I park my car? Did I eat breakfast today? Did I buy this at the grocery store? Those are the first things to go with Alzheimer's disease. After a while, the degeneration spreads to other areas of the brain, and that's when you start to see people forgetting who their children are or forgetting some of those longer-term things.

Dr. Biology:

Got it. Whitney. I'm really enjoying learning about memory. Which reminds me, there are three questions I ask all my guests.

Dr. Biology:

OK. 

Dr. Biology:

So, are you ready?

Whitney:

Yes.

Dr. Biology:

All right. The first one is, when did you first know you wanted to be a scientist?

Whitney:

I would say probably in college I knew that I loved science. I was a psychology major, and I liked cognitive psychology because it utilized the scientific method so precisely. And I really was attracted to that. So, if I'm honest, I think I'd always really liked science I'd always taken a lot of science classes in high school, but probably college is when I thought, oh, this is something I could do for a career.

Dr. Biology:

Yeah. I call it the aha moment where you finally say, this is it.

Whitney:

Yeah.

Dr. Biology:

All right. So, now I'm going to be a little bit mean.

Whitney:

OK?

Dr. Biology:

I'm taking it all the way. So, you're not going to be a scientist. I'm taking that away. And because you are really good at teaching, typically you're passionate about that. So, I'm going to take those two away because I want you to stretch a little bit. What would you do? What would you be if you could be anything, if you couldn't do those others?

Whitney:

Well, I like working with people. I like projects. I like getting things accomplished. So, I would imagine myself as maybe some sort of manager who works with people gets a team of people to accomplish goals.

Dr. Biology:

Good. I'm going to push you a little bit more. I'm going to give you some more abilities. I'm not going to turn you into a superhero.

Whitney:

OK.

Dr. Biology:

But you can do anything you ever wanted.

Whitney:

I really love cooking, so I guess if I could do anything, I would love to make a cookbook just like invent some recipes, do some research and development of food. And I guess, is that a little too science, research, and development?

Dr. Biology:

No, no. I think it's nice because part of this exercise is the fact that no matter where you go, you end up in science.

Whitney:

Yeah. Exactly.

Dr. Biology:

Right? Because cooking, baking, there's a science.

Whitney:

It's a science.

Dr. Biology:

If you're going to do a cookbook go back to your organization. So,, yeah, I think it's great. And the last question is, what advice would you have for a future psychologist? Someone who maybe wants to work in the world of memory?

Whitney:

Well, I would say be curious that would be my broad advice is be curious about whatever topic you're going to study that curiosity will fuel you when things are hard. It will keep you moving. And it's a generally a just a great quality for everybody to have. So, curiosity, I would say emphasize curiosity. Try to avoid judging curiosity, not judgment. And then I would also say take some coding classes and some math classes. Those are classes that I did not appreciate and did not take as an undergrad. But they're just so important for the scientists that are coming up.

Dr. Biology:

I couldn't agree more And one of the nice things is if you can find a coding class or a math class that's tied to your interest, it becomes much easier.

Whitney:

Yeah.

Dr. Biology:

Because it makes sense. It has a purpose. And I think, again, back to your memory and our discussion today about how you remember things if it's applied now, it's got more paths than just learning how to do a particular formula or learning how to do a certain kind of coding. You actually have something that's built into that.

Whitney:

Yeah, exactly.

Dr. Biology:

Well, Whitney, I want to thank you for being on Ask A Biologist.

Whitney:

It was my pleasure. Thank you.

Dr. Biology:

You have been listening to Ask A Biologist, and my guest has been Whitney Hanson. She is a cognitive psychologist and principal lecturer in the Department of Psychology at Arizona State University.

Now, be sure to check out the episode notes and transcript for additional links where we will also include a link to our Nervous Journey story about our brain and nervous system. And for those who listen to us using an app that shows chapter links and images, we will also include images there.

The Ask A Biologist podcast is produced on the campus of Arizona State University and is recorded in the Grass Roots Studio, housed in the School of Life Sciences, which is an academic unit of The College of Liberal Arts and Sciences. And remember, even though our program is not broadcast live, you can still send us your questions about biology using our companion website. The address is askabiologist.asu.edu. Or you can just Google the words. Ask A Biologist. As always. I'm Dr. Biology and I hope you're staying safe and healthy.