- Oh.

- Got it.

- We got one in.

- [Rob] Are you feeling curious?

- [Crew] Yeah.

- [Rob] Today on "Curious Crew."

- Oh.

It's all hands on deck.

17,000 receptors.

As the crew explores the sense of touch.

Give your receptors a high five to somebody else.

All right, excellent.

- [Narrator] Support for a "Curious Crew" is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages, while teaching lifelong saving habits.

More information is available at MsuFcu.org.

By the Consumers Energy Foundation dedicated to ensuring Michigan residents have access to world-class educational resources.

More information is available at ConsumersEnergy.com/Foundation.

Consumers Energy Foundation, supporting education and building sustainable communities in Michigan's hometowns and by viewers like you.

Thank you.

(upbeat theme music) (upbeat theme music continues) - Hi, I'm Rob Stephenson and this is- - [Crew] "Curious Crew."

- Welcome to the show everybody.

We always like to start every episode with a couple of discrepant events because discrepant events stimulate.

- [Crew] Curiosity.

- That's exactly right.

And I've got some fun ones for you today.

In fact, the very first one I like to call, What's the Point?

You'll see why in a minute.

Now, Lucy, you're gonna help us out with this one.

I informed Lucy right before we started rolling cameras that she's gonna be blindfolded in this little exercise.

So go ahead and put that blindfold on yourself, Lucy.

And I'm gonna tell everybody else what I'm gonna do.

I have in this box four probes, okay?

And these probes have either one or two little points on them.

And what I'm gonna do is I'm going to place some of these on the back of Lucy's hand and I might do the same one more than once.

And she's gonna report out for us if she feels one or two probes.

Now, fortunately this doesn't hurt, but it's very interesting, okay?

So Lucy, we're gonna go ahead and get started.

Do you feel one or two?

- Two.

- She felt two.

Lucy, do you feel one or two?

(upbeat music) - [Lucy] One.

- Lucy, do you feel one or two?

- One.

- One.

Lucy, do you feel one or two?

(upbeat music) - One.

- Okay.

What was that like, first of all.

- They were like really hard to decide which ones were which.

- This is the very first one I did, which is spread apart with two centimeters.

We did this one next and you reported it as one, even though there was two probes, this one you reported as one, even though there was two probes and this one you reported as one, which was correct.

Now that seems strange, doesn't it?

- Yeah.

- Okay, Rishab your turn.

Now Rishab, you too are gonna get blindfolded, but I also asked Rishab to put on these gloves.

I'm not gonna make you do any dishes, I promise, but underneath this box, I would like you to try to identify the items that are there.

And if you get them right, I will remove them from the tray.

Now the first thing that you need to be aware of, Rishab is I just want you to use flat hands.

You can move them around and I'll even place your hands over the tray and you can report anything that you can identify.

- [Rishab] It's bumpy, so there's some bumps.

- [Rob] Okay.

- I can't really tell anything much else.

- Okay, let's take off just one glove, Rishab.

You can pull off one and you can hand it to me.

Now I'm gonna ask you to do it again with flat hands continued, and see if you can identify- - Oh, it's so cold.

(Rob laughing) - Oh wow.

- Okay, anything else?

- [Rishab] Huh?

I can also feel the texture, it's slippery.

- Okay, slippery and cold.

Okay, Rishab, let's take off the other glove.

- All right.

- And now I will let you manipulate these however you want to with your hands.

Go ahead and put your hands down on the tray.

You can manipulate anything that you want.

- [Rishab] What is this?

(Crew and Rob laughing) Oh, this feels like an ice cube.

- That is an ice cube.

I'm gonna get that off.

Nice job.

Excellent job.

(Crew giggling) I'll take that away from you, well done.

Anything.

- Oh, this is clay.

- [Rob] Oh, nice.

- Oh, (Rishab laughing) this is like, I don't know, some kind of ball with holes in it.

- Some kind of ball with holes in it, that was very good.

And we'll try one more as you start feeling around for- - [Rishab] Oh, this is feather or something like it, something fuzzy.

- Okay, let's go ahead and pull off your mask, Rishab.

And you can look at what you're holding right this minute.

So you got a little piece of cotton there, you never even made it over to the shell or the orange.

What was that like, Rishab?

- It was interesting, because when I started out I couldn't really tell much just that the general shape of all the items.

But then as I started taking off the gloves and starting to like grip the items, I could tell and get more information to determine what object these were.

- Excellent job, okay, so we've got a couple of interesting discrepant events here.

I'm gonna invite three of you to do a little scientific modeling, to see if you can explain these phenomena by the end of the show.

You can use information you learned throughout the show to revise your thinking too.

So who wants to do a little modeling moment today?

Ishi, okay, Julia, Ollie, you three are gonna do that.

Now, does anyone have a guess what we're gonna be investigating today?

Macy, what do you think?

- The sense of touch.

- (Rob gasping) Sense of touch.

That's exactly right.

Stick around, After all, you don't wanna lose touch.

(upbeat theme music) - So let's figure this out, what did you notice, Ollie?

- I thought it was really interesting how Lucy had a hard time figuring out whether Dr.

Rob was using one or two points.

- I know.

I thought hands are very sensitive.

- I think they are.

Rishab was able to tell what some of those mysterious materials were.

- That's true, once he had taken off his gloves.

(upbeat theme music) - [Rob] Your skin is constantly at work sensing the world through your sense of touch.

In fact, your skin is the largest sensory organ in your body.

The skin has a lot of sense receptors so you can identify temperature like if something is hot or cold.

You can also tell the difference between a faint touch, a vibration, if your skin is getting stretched, - Ow!

- Or when it experiences deep pressure, those receptors send messages to your brain all the time, even though most of those messages are ones you don't pay attention to, your sense of touch is always working.

Wow, that's cold.

(upbeat music) (upbeat theme music) - So Lucy and Rishab were pretty good sports being willing to wear blindfolds.

Of course, I thought you might like that opportunity too.

(Rob and Crew laughing) So for this little investigation, Ben, Ishi, I'm gonna have you both put on a blindfold.

So go ahead, you have them there.

Once you have them on, Julia and I are gonna set up the rest of this investigation.

We've got a towel in front of each of you.

And go ahead Julia, we're gonna lift off these towels and underneath we have two wooden puzzles.

Each one has four pieces.

Julia, let's just take the pieces out, here's our challenge, Julia's gonna give one piece to you, Ben, I'm gonna give one to Ishi, and we're gonna see if you can actually get it in the correct spot.

So go ahead Ishi, I'm gonna put this in your hands.

You can feel it.

How's that going, Ishi?

- I'm like trying to feel the space of each box to see if it like fits the shape of the actual puzzle piece.

- [Rob] Okay, Ben, what's your strategy there?

- I'm just trying to feel out each individual one and then come back to this.

- (Rob and Crew laughing) Okay.

- Not doing great.

- Not doing great.

I love your persistence though.

(Ben laughing) Oh, we got one in.

Oh, Ishi, yours is just about to go in.

Oh my gosh, you went in, look at that, go ahead, take off your blindfolds.

Was that tricky?

- Yeah, these are really weird shapes.

- Yes they are, now, it would've been a lot easier if I'd given you a really obvious shape, like a triangle or something like that.

But if you look at the outlines of these, it's not shaped like the pig or the cow.

They're these random shapes that are really hard to differentiate.

Julia, I don't wanna leave you out.

(Rob and Crew laughing) Julia, I have a blindfold here for you as well.

And you're gonna put yours on.

And once yours is on, I'm going to take out a little cookie cutter from my "Curious Crew" box.

Oh, I'm gonna use this one, put your hands out and I'm gonna place this in your hands, okay?

And you can manipulate that and see if you can identify what is this shape?

- Oh, it's a clover.

- It's a clover.

- Yeah.

- Take off your blindfold.

Now how were you able to figure that out?

- Because of those like rounded shapes here, there was three of them and then there's a stem.

- Excellent job, and so now clearly if we have a shape that is more defined, that's a little easier to create that mental picture, than these puzzle pieces, which are a little bit more random in order, nice job.

Now first thing that we have to remember when we're talking about the sense of touch, our receptors in our skin are going to be triggered by touch, pressure, temperature, or some combination of those.

What you just had to do was to build a mental picture just by moving your fingers around those objects.

This is an investigation you can try at home, but I will warn you, it's a little challenging.

You might even say it's a little touch and go.

(electronic swooshing) You may have noticed that it was easier to identify shapes when the crew could use their fingers.

This is because there are more than 3,00 sensory receptors in a fingertip.

Your body has millions of receptors in the skin to identify different kinds of touch.

But some parts of your body have more than others.

And this makes those body parts very sensitive.

Fingertips are a great example they have a lot of receptors close together so the sense of touching your fingers is very sensitive.

Your toes and lips have a lot of receptors too, so they are also sensitive, amazing.

(upbeat theme music) So I have a couple more fun investigations for you.

And the first one I like to call the touchy trick and, Rishab, you're gonna help us out for this.

And Demetrius, you're going to be our volunteer.

- Okay.

- Okay.

First of all, let me explain what's gonna happen.

I'm gonna have you get blindfolded.

So once you're blindfolded, I'm gonna give you this blue ballpoint pen in your right hand and then your left hand is gonna go down on the table.

Rishab is going to use the red pen and put a dot somewhere in the palm of your hand.

Your goal is to see if you can get close to it with the blue pen.

- Oh.

- Okay.

So go ahead and get yourself blindfolded here.

This is a tough challenge, certainly one you can try with friends and family at home.

I may even have Rishab do another dot somewhere besides the hand, okay?

Here is the pen uncapped in your right hand.

You get it oriented, there you are.

All right, just hold your left hand steady and Rishab whenever you're ready.

(gentle music) So now you try to get yourself oriented to that spot and place a dot, okay.

And let's try another one, Rishab somewhere else.

(gentle music continues) Okay.

(gentle music continues) How do you do over there on that side, Rishab?

You can go ahead and take off your mask, Demetrius.

- [Rishab] He was pretty close.

- Pretty close.

And you are fairly close here as well.

Our skin is filled with nerves.

It's your largest sensory organ in the entire body, but those nerves are not proportionally distributed.

Sometimes they're closer together and sometimes they're farther apart.

So we're gonna prove the point.

Mackenzie, you're gonna help me out for this point, I'm gonna ask you to turn your back to me and I'm going to select an object and place it against your lower back, okay?

You tell me what you think the object is.

- It feels like a shell.

- Feels like a shell, okay, Mackenzie, go ahead and put your hands behind your back.

I'm gonna let you manipulate this and see if you can identify it.

- It feels like a pine cone.

- A pine cone.

Well done.

I'll take that from you.

Excellent job.

I'm gonna put one more on there.

(gentle music) Okay, you tell me what you think that is.

- I can't really feel it.

- Okay, Mackenzie, turn around.

I'm gonna show you what this is.

I was placing a sponge right along the curve of your back and you couldn't really feel that very well, could you?

Here's what I mean, we've got much more sensitivity in your hand and much less in your lower back.

It's a lot harder to identify that stimulus when you couldn't touch it with your fingers.

But here you could identify that as a pine cone.

Nice job, thank you crew.

I'm so glad we could touch base on this investigation.

(electronic swooshing) There is one area of the brain that processes your sense of touch and it is called the somatosensory cortex or sensory cortex.

Different regions of the sensory cortex receive touch signals from different part of the body, but those regions differ in size.

For example, the brain space dedicated for touch signals from your hand and fingers is much larger than the region for the whole trunk of your body.

So if a body part has a lot of touch receptors, then it needs a larger area in the sensory cortex to process all that information.

I know from my cortex that feels soft.

(cat meowing) (electronic swooshing) (upbeat music) - [Announcer] STEM challenge.

- So have you been having fun investing in your sense of touch today?

- [Crew] Yeah.

- I've got a really good STEM challenge for you today.

You are going to be designing your own two-point discrimination tester.

Are you ready to start your builds?

- [Crew] Yeah.

- Go for it.

- What distances were you gonna do?

- 15, 37.

- I'm doing five.

- The materials that we're using is tape, toothpicks, a piece of paper and a ruler.

- Yes, I finally got one.

- I got my first one done.

- Now we're moving on to testing.

- Okay, you ready to test?

- I'll be tested.

- So with the two point discrimination testers, we were trying to figure out if two points felt like one point or two points and if one point felt like two points or one point.

- Should we try it on the palm or like on the inside of your arm?

- Oh yeah, that'd be like fingers.

- Our fingers, they could feel the two points versus the one points very easily, but different parts of their body, like their upper arm, was not very sensitive and one point often felt like two and the two point often felt like one.

- That's one.

- That's two.

- That's just one.

- That's two.

- No, that was two.

- That was two?

- Now that I understand which parts of the body can differentiate two points versus one point, it actually seems very cool.

(upbeat theme music) - Two, guys.

- I'm gonna interrupt you.

I can see you all testing each other with your two point discrimination testers.

Ben, what was that like for you?

- When the two pokes were closer together, it was harder to tell which ones were one and which ones were two.

- That close proximity it's really hard to differentiate that.

Julia, what's something that you noticed.

- Personally, I had a hard time telling all of them apart.

Like even the one I thought was two points.

- (Rob laughing) That's happened to me as well you are not alone, this is an interesting test.

Demetrius, what's it like for you?

- The higher up the toothpicks went up on your arm, it was harder to tell if it was one or two.

- As soon as we get those receptors spaced out further and further, it gets a lot more difficult to identify one point versus two.

And sometimes it's just hard in general isn't it, Julia?

Excellent job crew.

You definitely handled this challenge with a touch of class.

(electronic swooshing) Even though our sense of touch is incredibly important, there is still a lot about it that we don't understand.

Neurologists and brain surgeons know more than most, but we keep making more discoveries about the sense of touch.

In fact, as touchscreen technologies have developed, Swedish scientists realize that a person's finger can feel a ridge change as small as 13 nanometers.

That is so small we can't even see it.

That means the human finger can sense a large molecule or even a single cell organism by touch.

Now that's sensitive.

(electronic chime) (upbeat theme music) So because we're investigating sense of touch, we're gonna be doing a very special investigation with something called von Frey hairs.

This is actually a test that neurologists do to measure someone's tactile detection.

Now what do I mean by that?

Well, we're going to use really, really fine fishing line 'cause I don't have real von Frey hairs (Rob giggling) and I've taken different gauge fishing line and attach them to popsicle sticks.

Now some of this line is a little thicker, like this one at 5/10 of a millimeter, which is still not very big.

And this one goes all the way down to 2/10 of a millimeter.

Now here's what's gonna happen, Macy, you're gonna help me out with this.

- Okay.

I'm gonna have you get blindfolded and then I'm gonna grab one of these little probes and just touch the hair on the back of your hand and gently push so it starts to bend.

Anytime you feel something, you let me know.

- Okay.

- Okay?

Go ahead and put that on and we'll decide which one we're gonna do first.

So you put your hands out on the table and I'll just use your left hand just so you're not surprised.

Whenever you feel something you just let me know.

- [Macy] I feel it now.

- You feel it now?

- Yeah.

- Okay, let's try another one, okay?

(gentle music) - [Macy] I feel it.

- Oh, she felt that one quickly, I noticed that.

We're gonna try another one.

(gentle music continues) - [Macy] Oh, I feel it now.

(Rob and Crew chuckling) - Now Macy take off the mask, I have to show you this this is just amazing.

We started with this one that's 4/10 of a millimeter and you noticed that one pretty fast.

5/10 You notice really fast.

Then I use the 2/10, I had it bent that far over.

There's a lot of receptors in the skin, but this is a great little device to measure someone's ability to detect pressure.

Now, let's look at something else.

I have some cards here with different shapes.

Now you'll notice that these have little raised bumps.

Anybody have a guess what this system is called?

- Braille.

- It is braille.

Yeah, you bet.

And in fact, I have the braille alphabet noticed right over there.

And can you see how many dot positions there are in the bottom, Ollie?

- Is that six?

- It is six.

And so when we're looking at the braille alphabet or the number system, it's different configurations of six potential dots, we orient them differently.

And then someone who is using their sense of touch to read it can differentiate that.

Now you just feel those shapes and describe for me is that easy to identify or not?

Especially if you're not looking at it.

- No.

- I don't know which line to start on, there's so many bumps, okay.

- (Rob laughing) So many bumps.

Now at the very bottom of your page there's actually a page number.

What's your page number?

- 15.

- 15.

There's a little number sign first and then two different designated dot sequences to show your numbers.

What's yours Macy?

- 17.

- 17, Ollie?

- Seven.

- Seven, okay.

I would like to try one more braille activity.

I've got a little cardboard cube here, but I've taken some nails and I've pressed them right through the cardboard to represent some of the letters in the braille system.

I've got B-E-S-T why?

'Cause you guys are the best so that's why.

Okay, Ollie, here's the challenge.

I'm gonna ask you to close your eyes and see if you can feel these to distinguish which side has the T on it, okay?

Close your eyes, put your hands out.

It's coming to you and you can start to configure and rotate around as you need to.

(gentle music) - E?

Ooh, this is S, maybe.

- This is not an easy task, it takes a lot- - [Ollie] Oh, no, this is T. - You were correct.

- Yay!

- He got the T for sense of touch.

Nicely done, in fact, I think you three you have the magic touch.

(electronic swooshing) Our sense of touch plays a significant role in our development.

It is the first sense that develops and is especially important for babies (baby cooing).

Snuggling a baby helps the development in their immune system to fight sickness, their digestive system, their emotional health and brain development (baby cooing).

Even as we get older, the sense of touch keeps us healthy.

And if we are on sports teams, scientists have found that players who fist bump, high five, and make supportive contact actually play better as a team.

High five for the sense of touch.

(electronic swooshing) (upbeat theme music) - Are you curious about careers in science?

Hi, I'm Genesis, and today I'm here with Shannon McVoy.

Shannon, can you tell me where we are and what you do?

- Absolutely, we are at the Michigan Bureau Services for Blind Persons Training Center in Kalamazoo, Michigan.

I'm the statewide Transition Services Manager and my job is basically to help students who are blind and visually impaired learn what they wanna do after they leave high school.

- What are transition services?

- Transition services are a series of activities and programs that we designed specifically for students who are blind and visually impaired to learn what it's like in the workplace and in post-secondary education.

- How is STEM involved in transition services training?

- A lot of students who are blind and visually impaired don't realize that STEM is an option for them.

So we try to focus on programs that will highlight STEM careers so that our students can really do some hands-on work.

(upbeat music) - Shannon McVoy taught me how STEM can heighten our senses, explore your possibilities.

(upbeat theme music) And now back to "Curious Crew."

(upbeat theme music) - So we know that the skin is the largest sensory organ, (robotic beeping) but the concentration of nerve endings are spread out between different parts.

- And that's why the hands and fingers are so sensitive.

But if the points on Dr.

Rob's testers are so close, it might feel like one, even though it's two.

- Each time someone got blindfolded, it made it a lot harder for them to identify different objects.

When Rishab got blindfolded, he kind of had to build a mental picture of what he was feeling, based on his sense of touch.

(upbeat music) - So have you had fun investigating your sense of touch today?

- [Crew] Yeah.

- I'm so glad about that.

Now you probably thought I was out of touch with these discrepant events at the beginning of the show, and I'm curious though, What's the Point?

Ishi, have you been able to figure out the point of my, What's the Point, discrepant event?

- Well, the paperclip applied pressure to Lucy's hand signaling nerves in the skin.

- Right but when two points are close together, it's hard to tell whether there's just one point of contact or two.

- Exactly, so we know as far as the sense of touch, we're talking about nerves all over the body, right?

And we know that those receptors can pick up touch, pressure, temperature, and even a combination of those.

But the two point discrimination tester is a great one to test our sense of touch.

Where are some sensitive spots in the skin, Julia?

- The fingers, the face and the lips.

- Okay, excellent.

But let's take a look at this chart over here.

If we were to use this probe on the shoulder, or the thigh, or the calf, the threshold distance is much bigger, so that would be way harder to detect.

So Ollie, what have we figured out about the mysterious materials?

- So when Rishab was wearing the gloves, it drastically reduced the amount of tactile information that it was sending to his brain, making it much harder to figure out what he was touching.

- The flat hand one was hard too, but he noticed temperature and texture.

- It was easier for him to identify the things when he could use his fingers.

- Absolutely, because we know how sensitive our fingers and hands are.

Okay, look at your hand for just one second.

Imagine this, there are 17,000 receptors in the palm of your hand.

You have 3,000 receptors in each one of your fingers, making your hands and fingers incredibly sensitive and sending a lot of information to your brain, manipulating those things much, much easier for Rishab.

So give your receptors a high five to somebody else.

All right, excellent.

Gently, of course, because with 32,000 receptors, you're guaranteed to feel that, nice job crew.

Now that you've put the finishing touches on this episode.

So remember my friends, - [Crew] Stay curious.

- And keep experimenting.

(electronic swooshing) Get your CuriosityGuide and see more programs at Wkar.org.

- [Narrator] Support for a "Curious Crew" is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MsuFcu.org.

By the Consumers Energy Foundation dedicated to ensuring Michigan residents have access to world-class educational resources.

More information is available at ConsumersEnergy.com/Foundation.

Consumers Energy Foundation, supporting education and building sustainable communities in Michigan's hometowns, and by viewers like you.

Thank you.

- (electronic beeping) That's our camera.

- I can see through the bottom.

- You are going to be designing your own two point.

I did it again.

I'm so sorry.

Okay (Rob clears throat and imitating electronic swooshing).

- All right.

Problem solved.

- Okay, he's back.

- I'm back, I didn't see nothing.

(electronic logo swooshing)