Backyard Brains is live from inside the classroom of Colegio Alberto Blest Gana in Santiago to present you 5 group projects brought to life by creative and passionate students. and the methodology we used to choose the projects. This high school has been like a second lab for Backyard Brains, where the students beta test our hardware prototypes and invent new classroom exercises. This year was the first year where the classroom made independent group projects, with a class size of about 15 students, ranging from 7th grade to high school seniors.
It can be a challenge to involve students in independent projects when it is their first time, so it is important to let the students conceive their own project ideas from the beginning. The ideas need to come from inspiration, not mandated from above. That’s why, to help out in the creative process, we devised an interview that would work like a conversation, where the student can start to imagine what they would like to build, or what problem they would like to solve. You can use this pdf as a guide
To guide some shy students that weren’t sure what they wanted to build, we suggested projects that the students could modify so that they could begin to feel that the idea we gave them is also their own. We then place the people that had similar ideas and interests into the same group. As a suggestion, if you are working with students with very different ages, it is important to mix it up a little in this area: always have a mix of older students with younger students.
The interview resulted in 5 projects:
The Electrocardiogram of the Clam.
This project was chosen by students that had an interest in animal physiological systems. Most of the students didn’t know before this experiment that a clam has a heart, because when you open it, the clam’s organs just look like a blob. It isn’t easy to notice distinct anatomical parts that look so different from the organs of vertebrates. After finding the heart, a challenge for students (and even for us teachers), we needed to make sure the heart was still moving and contracting. Unlike a vertebrate heart, the beat is not like a regular clock, it can stop a long time and then restart again.
When we saw a heart beat, we placed one red signal electrode in the atrium and the other in the ventricle. The third electrode (ground-black) was placed farther away the clam. These three electrodes were connected to the Backyard Brains Heart and Brain SpikerBox to make the recordings.
And glory of glories, we had success!
However, we don’t know if what the students recorded is in fact an artifact arising from relative movement of the recording electrodes, giving rise to a baseline shift that mimics in some ways the P and QRS features of a typical ECG. Our next step is to manually deform the heart to see if similar features arise. If not, then perhaps we observed a real biologically-generated clam electrocardiogram. You can download our recording here.
Muscle-Keyboard-Interface.
In this project, chosen by one gamer and talented student, he used the electricity generated by voluntary muscle contraction to take over the keyboard of a computer.
The appeal of this project is that muscle interfaces work like a charm, a microcontroller is easy to program, and it’s all very low cost. To accomplish this, we decided to control a very easy and accessible video game with the electrical impulses of the muscles, using our Muscle SpikerShield combined with the Arduino Leonardo. The advantage of an Arduino Leonardo is a computer can recognize the Leonardo as a keyboard input. The video game he chose was Google Chrome’s offline dinosaur video game: you can play it fine with only one key on the keyboard (the space bar makes the dinosaur jump…though pressing the down arrow key also makes the dinosaur duck). It’s fun, and you don’t need internet or any specialized gamer hardware to run it. You can download the code here.
Cockroach Labyrinth.
The idea of this project was to build a labyrinth to learn about cockroach behavior and food preferences. Could they learn the route to reach a preferred food source faster over time, say, a banana slice instead of a potato slice?
Unfortunately, this project was done in the open air during winter, with a temperature of 40-50 degrees Fahrenheit, a temperature at which cockroaches are not that hungry and not highly active, so using food as an incentive didn’t work. Also, another problem was that the cockroaches were able to climb the walls of the labyrinth. Nevertheless, the students got over these obstacles and had success with one experiment: they placed a lid on half of the labyrinth to make that section dark, and left the other half uncovered, so light could get in. They released the cockroaches, and after one minute, all of the three cockroaches were in the dark side, just like Anakin Skywalker. A small sample size, but convincing evidence of what was suspected all along: cockroaches prefer dark spaces.
The Polygraph Lie Detector.
This project was from a group of students interested in the physiology of lying. At Backyard Brains we love to extract and read physiological signals, and as the traditional polygraph measures skin conductance, respiration, blood pressure, and heart rate, building a DIY polygraph is right in our wheelhouse. To keep it simple in the beginning, together with the students we decided to focus on skin conductance alone, something we have been asked to study before many times.
When someone lies, there is the hypothesis that the persons subtly increases sweating. Since sweat is salty water, and salty water is much more conductive than dry skin, we should be able to measure a decrease in skin resistance across the palms when a person is lying.
The first experiment this group did was very simple. They checked the skin resistance using a multimeter and patch electrodes across our inner palms before and after running on the treadmill The results were the following:
Before running 5 kilometers
97 Kiloohms
After running 5 kilometers (24 minutes)
12 Kiloohms
The results are crystal clear, a body covered in sweat is much less resistant to electrical current than dry skin.
The next step was to find a way to graph skin resistance in real time, and test it using lies instead of jogging. The students made a simple circuit in Arduino where the grey cables go from 5 V input to analog 0 in arduino, buuuutttt, the cable is cut and the person must grab each end of the cut cable with each hand. They then used the sample code “graph” which graphs the voltage value of the analog input, which, of course, will change depending on the resistance of the skin across the student’s hands.
When they tested using lies, there was no significant change in the value of the skin resistance, as the effect is simply too subtle, if it even exists at all, to measure using our equipment. Although the final test wasn’t successful, at least the students tore down the myth that galvanic skin response can detect lies by itself. That’s why complete polygraph machines also measures respiration, blood pressure and heart rate, and the combination of all these elements supposedly makes the polygraph a more reliable tool for detecting lies. If we continue this project in the future, we will look into integrating these other physiological signals in addition to skin conductance.
Muscle Electrophysiology in soccer.
This group of students was interested in how electromyography changes when making different strength kicks in soccer: kicks made for small distances, like close passes, and kicks made for big distances, like aiming for the goal or to a player that’s far away. To do this, the group placed two signal electrodes in the abductor muscle of the quadriceps, and the ground on the knee. The students then placed masking tape in the floor, marking the distance in meters, and the subject kicked the soccer ball to a friend waiting at the various meter marks.
The different distances they used were 5 meters (16.4 feet), 3 meters (32.8 feet), 15 meters (49.2 feet), 20 meters (65.5 feet), 25 meters (82 feet), 30 meters (98.5 feet), and 35 meters (114.8 feet). Below is a sample of the data they recollected:
As you can see quite nicely, the amplitude of the EMG of the quadriceps increases as the soccer ball kicks become more forceful. This was our hypothesis, that as you recruit more and more muscle fibers during a movement, the EMG signal amplitude will increase due to the higher number of action potentials generated and the superposition that results.
This experiment on the physiology of sports was very fun for the students. They also tried baseball pitches, but the rapid “snap-back” movement of the arm would always cause the cables attached to the triceps to come flying off. With basketball, they did not notice a dramatic difference between two point and three point shots. So, as the students were happy to report, for now, soccer is the best for studying the physiology of sports using our equipment! We will keep trying with baseball for all the Detroit Tigers fans out there.
****
These final projects were worked on once a week, for 1.5 hours, for 2.5 months, and on October 30th, the students presented their results to the community to much success. The sports physiology and the clam EKG experiment will be the first to be transformed into formal Backyard Brains experiments on our webpage, so stay tuned! If you are interested to having the students in your school working on personal group projects, feel free to contact us, and we investigate the world together!
Engage your students with even more Real-World Science
PLTW is a powerhouse in the STEM Ed movement. Thanks to them, many schools are offering courses in Engineering, Computer Science, and, most exciting to us at BYB, Biomedical Sciences. Thanks to these courses, students have the opportunity to learn about all sorts of incredible career and research fields (Including Biomedical Engineering and Neuroscience!), and the courses are led by inquiry and hands-on activities.
We work with many PLTW teachers who have incorporated Backyard Brains tools and experiments to help enrich their courses and to provide exciting, hands-on labs and materials for some of the trickier to cover concepts. Below I have just a few examples of how to incorporate new and novel labs and demonstrations into your PLTW course to empower and inspire your students.
If you teach a PLTW course, this will be a great resource for you as you seek ways to further engage your students and give them real-world, hands-on experiences. If you don’t teach a PLTW course, well, as they say, steal everything that isn’t nailed down or protected by licensing (none of our materials are!) and use it to improve your own classes!
Medical Interventions
Unit 3: How to Conquer Cancer
Lesson 3.3: Treating Cancer
In brief, here are a few of the performance objectives for this lesson
Design and create a simple model of an arm that is able to pick up an empty Styrofoam cup.
Complete a laboratory investigation using data acquisition software and probes to explore biofeedback therapy.
Design an experiment to test the effect of relaxation techniques on their heart rate, respiration rate, and skin temperature.
Design and present a comprehensive rehabilitation plan for an assigned patient.
Prosthetics and assistive technologies are really exciting examples of applied sciences. It shows students how they can combine an interest in the life sciences with computer science and engineering. We’ve had many PLTW use Backyard Brains’ The Claw during this lesson to give students a hands-on experiment with a real neuroprosthetic. By recording from the muscles in their arms (or anywhere in their body), students can dynamically control the claw.
Biofeedback is an umbrella which includes neuroprosthetics, but within these objectives, it is being investigated as a therapeutic system. Learning to control or affect certain functions of your body can be hard. Learning to REGAIN control following injury or illness can be even more challenging. The goal of Biofeedback systems is that they provide an external indicator of how the subject is progressing. This includes everything from regaining control of movement in your body, to simply staying calm, managing your heart rate, or meditating with an EEG device!
Check out these Backyard Brains experiments which use the Heart and Brain SpikerBox to explore some of these signals, then your student can design a biofeedback experiment observing EEG, EKG, or even EOG (Eye Potentials).
Sounds like electrophysiology to me! In brief, here are a few of the performance objectives for this lesson
Use an interactive website to manipulate ions in a membrane and generate an action potential in a neuron.
Complete a laboratory investigation using data acquisition software and probes to explore reflexes in the human body.
Design an experiment to test factors that could impact reaction time.
A question with an obvious answer: would you rather your students learn about neurons by making a pipe-cleaner 3D model and clicking through a web-app? Or do you want them to record living neurons from a model organism, turning the introduction of neuroscience into a hands-on, quantitative lab? Much like the NGSS MS-LS1-8, this is an opportunity to introduce students of any age to Neuroscience by performing one of the most fundamental experiments in neuroscience: recording directly from a neuron!
Using the Neuron SpikerBox, students can first observe live Action Potentials, then learn about how these signals are interpreted – a process called Rate Coding.
But what about Humans? We believe that using cockroaches and other model organisms to introduce neurons and Action Potentials is an incredibly important and powerful learning experience. But we’re not about to ignore the human element…
When we show students the Human-Human-Interface (seen in the above TED talk), it never fails to amaze and surprise them. It is also an incredibly effective way to illustrate the role that electrical systems play in sending and receiving signals throughout the human body. One PLTW teacher we work with said she usually tries to invite the principal in to be the subject of the experiment, making it especially fun for the students when they get to take control!
In this lesson, there is also an emphasis on understanding reflexes and reaction time – rightfully so! Mental Chronometry is the foundation of modern neuroscience. Before we studied Neurons, we studied reaction times to externally investigate the nervous system. Could you react faster to a sound, a light, or a touch? Differences in these reaction times and, consequently, differences in reflexes, informed an early understanding of neural circuitry, and you too can perform these experiments!
Check out these experiments below which students can get started with before hacking them to create their own projects!
Here are a few of the performance objectives for these lessons
Investigate Muscular Anatomy and learn about the link between Muscles, Neurons, and your Brain
Learn how muscles are composed of units called sarcomeres, which contract and shorten when exposed to electrical stimuli.
Complete a laboratory investigation using data acquisition software and probes to explore muscle fatigue.
Design an experiment to test the effect of feedback, coaching or competition on muscle fatigue.
These lessons are a great way to bridge the gaps between many different interests. Athletes in your class are going to be excited to learn about exercise physiology, your bio students are going to love to learn about motor-units and muscular anatomy, and all the students love a little bit of competition and hands-on experiments…
Muscles
Beginning with the mechanisms which excite your muscles and which we can record data from, students learn about and record EMG signals from their own muscles using the Muscle SpikerBox Pro. This allows your students to hear, see, and record the electrical activity of their muscles, ultimately facilitating a number of exciting (and competitive) labs.
But first, your students can explore muscular anatomy and learn about Agonist and Antagonist muscle pairs, and then take a deeper dive to record from Motor Units.
Muscle Fatigue is the next phenomena to investigate, and here’s where things can get competitive (or, if you prefer, comparative!)Students can design their own muscle fatigue experiment or comparative inquiry. By quantifying the strength of the beginning and end of an EMG signal, students can create a Rate of Fatigue over time which they can then compare between each other, or themselves as they continue to exercise over several trials in a day, or over several months. Does a competitive format inspire a student to hold out for longer (we call this hands-free arm wrestling) or will muscles fatigue at a similar rate regardless? That’s for your students to investigate!
As you can see above, there are a lot of ways you can take your PLTW lessons to the next level by engaging your students with hands-on electrophysiology. All of these tools are designed to be accessible and easy to use and, as you can see above, they are very affordable.
The above devices pair with free data-acquisition software called SpikeRecorder, which you can download on any smart device, tablet, Chromebook, or computer. For more information, please don’t hesitate to reach out to our General Email.
Together, we are working to inspire a new generation of neuroscientists, biomedical engineers, Doctors, and other STEM professionals. And for those students who do not pursue a STEM field, we are teaching them critical thinking skills, problem-solving strategies, and the knowledge they need to know to be scientifically literate citizens.
As I was doing this project, the specter waiting for me as we started wrapping up our projects was the prospect of having to answer the question, “So what?” What is the point of this research? I spent most of my time working on the “methods,” the techniques (surgeries, soldering, coding) that became the experimental setup.
Everyone knows that you can’t do good science without a solid experimental setup, but before you design your experiment, you need a question to answer, a hypothesis. This imperative is known as hypothesis-driven research, and it’s the gold standard for doing science because it forces you to do novel work that will benefit the world. Sure, penicillin was discovered by accident, i.e., without being driven by a hypothesis, and a lot of good science is done by pursuing curiosity, but scientists usually strive for the traditional hypothesis-driven approach.
Well, for this ten-week program, you can’t do hypothesis-driven research; instead I had to formulate a valuable question while running experiments. These experiments, which I was designing on the fly, would in turn limit the kind of questions I could ask! For example, since I was making an EMG probe, I had to formulate a hypothesis related to mantis shrimp EMGs. I couldn’t all of a sudden decide that I actually wanted to see what neurotransmitters were involved in striking behavior, because you can’t measure neurotransmitters with EMG.
Well, “So what,” though? Mostly, it’s that no one has done this before, particularly in terms of making a backpack, comparing strike EMGs across mantis shrimp species, and, to a lesser degree, comparing power amplification across taxa.
The backpack
Pennywise rocking his backpack.
Electrophysiology-focused mantis shrimp research has been purely acute and terminal, meaning that you only get one day’s worth of data from an animal before you are done with it. No one had ever made a chronic setup for EMGs in mantis shrimp. If you have a backpack that can be left on the animal for days or weeks at a time (i.e., chronic), you spend less money on getting new specimens, there is less loss of animal life, and you can have what’s called a within-subjects experimental design. Within-subjects designs have the advantage of allowing you to compare data from the same subject (i.e., each individual mantis shrimp) on different days in addition to comparing subjects to each other, making it easier to believe whatever you find. Surprisingly, no one has spent time making something like my backpack, so the methodology of my research is actually one of my biggest findings!
Also, if all goes well, the mantis sheds the backpack when it molts. I noticed today that Featherclown did exactly that, and is looking bigger and better than ever.
Different species of mantis shrimp might not punch in the same way
The phases of extensor activity leading up to the strike
As we all know, there are hundreds of species of mantis shrimp. However, no one has tried comparing EMGs of the strikes of two different species of mantis shrimp. What if you’re interested in studying a species besides those two? The Sheila Patek paper that I keep (post #1)on (post #2)referencing (post #3) examined twelve parameters of strike EMGs in Neogonodactylus bredini. Even though I recorded from three species, I was only able to get consistent strikes from one: Pennywise, the Gonodactylus smithii. The big question on my mind was about the difference between how Neogonodactylus and Gonodactylus build up energy to strike, visualized as above. From those twelve parameters in the Patek paper, I decided to replicate two: Duration of cocontraction phase, and number of extensor spikes in the cocontraction phase. I know. That’s a lot of explanation. Here are the graphs. Individual 0 is Pennywise, 1 through 6 are Patek’s Neogonodactylus-es.
Same number of spikes, but Pennywise is heads and shoulders above the Neogonodactylus-es vis-a-vis duration. At least, possibly. This is only one individual. Ideally I’d have at least as many Gonodactylus as Patek had Neogonodactylus, so I can’t say if Pennywise’s strikes are representative of his species’ entire population.
Power amplification across taxa
This is easily the least hypothesis-driven part of my project. The question I’m answering is, more or less, “how does mantis shrimp power amplification compare to that of crickets?”, and I’m using cockroaches as a sort of non-power-amplifying control group. Some speculative work has been done about the similarity in power amplification in crickets, so this part isn’t that new either. I’m not carefully measuring the behavior of crickets or cockroaches, so I can’t say a particular burst of EMG spiking produced a particular movement. I’m just comparing details about the bursting itself, which I selected in the cricket and cockroach data based solely on the bursts’ shape. It turns out that the power-amplifying species show an increase in the number of spikes (ie, average firing rate) from the first half of each spike burst to the second half, whereas the cockroach is a good control since it is all over the place and does not show a trend.
One analysis I wished I could have done involved the overall shape of the bursts itself. See how the cricket and mantis shrimp bursts seem to be hourglass shaped while the cockroach’s is more boxy? That is something I want to quantify eventually. Anyway, the rest of my poster can be found at danpollak.com/BYB.html.
Odds and ends
Future directions
Looking back, I wish I could have done a few things differently, had I enough time. The backpack was plagued by water infiltrating its crevices, shorting it and rendering it useless until I could wick the moisture out with a rolled-up paper towel. This is why I had to revert to the Patek restraint, where the animal is held half-in, half-out of the water. If I could connect a waterproof plug to the backpack and release the mantis shrimp into its home tank, I could elicit striking behavior while the animal is actively defending its burrow against an “intruder” (i.e., my hand or a pen). That would open the door to research into how EMGs figure into mantis shrimp predation, social interaction, and myriad things I couldn’t speculate about. I hope that someday an intrepid marine biologist will see that chronic, modular EMG is possible and will simplify and waterproof it.
Seaborn
Slick graph huh? The highlight of my week was discovering a programming tool for visualizing statistics called Seaborn. I discovered that it is named after Sam Seaborn, Rob Lowe’s character on The West Wing, which, being my favorite TV television show, made me very happy. The kind of idealism I mentioned briefly at the top of this post, about how the research you do must benefit the people around you, is a theme on The West Wing, transposed onto policymaking. Sam Seaborn is a gifted speechwriter for the President, and is wont to expound on the value of integrity or honesty or some other embarrassingly bushy-tailed thing, except that after hearing him you really want to go around thwacking people on the head for being less than they ought to be. In figure 2 below, we see Sam Seaborn making the case for public education.
You might see why Seaborn is an apt name for a tool that tries to turn statistics into persuasive visual arguments, clear and careful communication that enables the best in us.
It’s been a blast to be a part of BYB’s program this summer, and I am grateful to those of you who took the time to skim even one of my posts. Thank you and sorry to Toothfinger and Beastie Boy for giving your lives to my incompetence with animal care. It’s a comfort to imagine you two in shrimp heaven now, burrowing to your hearts’ content. Please Daniel we can’t keep doing this.
