Hands-on Activity Studying Brain Waves

Learning Objectives

After this activity, students should be able to:

• Identify and describe the five types of brain waves.
• List some brain disorders/diseases that may be diagnosed with the help of EEG analysis.
• Describe what a Fast Fourier Transform (FFT), the Power Spectral Density (PSD), and bandpass filter.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

Materials List

For each student:

• laptop or computer
• access to YouTube
• a Google account and use of Google Colaboratory: Google Colab

Worksheets and Attachments

Pre-Req Knowledge

A familiarity with basic wave analysis (understand frequency, amplitude, and period of a wave). Students should also have a basic knowledge of logarithmic scale.

Introduction/Motivation

Have you ever wondered how your brain works? Or how you are able to make decisions? Or how you can quickly recognize when something is too hot or cold? What causes us to feel certain emotions? All these characteristics of us lie within the waves that travel through the brain.

Brain waves specifically carry energy to different parts of the body through your nervous system. Your sensory neurons send signals detailing what you feel in the environment to your brain, which can then send action signals to your motor neurons to respond to the environment. Scientists and engineers must consider the “normal” ranges of frequencies and amplitudes of the brain waves if they are using or designing a device that will interact with the body. When diagnosing brain disorders or injuries, doctors may measure the patient’s electroencephalogram (EEG) and look for abnormalities in the brain waves. Engineers and researchers are developing algorithms and devices for understanding the brain and treating known brain disorders and diseases. They study electroencephalograms (EEGs) of patients to look for patterns or signs of these disorders and diseases so that they can be readily diagnosed and monitored. In addition to finding patterns, researchers are also studying brain entrainment, or the rhythmic alignment of a person’s brain waves with their environment.

In this activity, we will discuss the basics of brain waves—this includes the five types of brain waves and their associated brain states and wave characteristics. You will also learn about some of the wave abnormalities that computer programs may recognize to diagnose brain disorders or injuries. After this activity, you will have a good understanding of how the brain’s activity level may be determined by these different types of brain waves.

Procedure

Background

Brain waves specifically carry energy to different parts of the body through your nervous system. Your sensory neurons send signals detailing what you feel in the environment to your brain, which can then send action signals to your motor neurons to respond to the environment. Scientists and engineers must consider the “normal” ranges of frequencies and amplitudes of the brain waves if they are using or designing a device that will interact with the body. When diagnosing brain disorders or injuries, doctors may measure the patient’s electroencephalogram (EEG) and look for abnormalities in the brain waves. Engineers and researchers are developing algorithms and devices for understanding the brain and treating known brain disorders and diseases. They study electroencephalograms (EEGs) of patients to look for patterns or signs of these disorders and diseases so that they can be readily diagnosed and monitored. In addition to finding patterns, researchers are also studying brain entrainment, or the rhythmic alignment of a person’s brain waves with their environment.
 

Before the Activity 

• Make copies of the What is a Brain Wave? Worksheet and the Analyzing Brain Waves Jupyter Notebook Worksheet, one copy per student
• Prepare to show the video from the What is a Brain Wave? Worksheet, 5:10-min long: https://www.youtube.com/watch?v=gvpuOBezW0w
• Find and print out images of the different types of brain waves and queue up videos with music that resembles the rhythm of the sound waves. Set up the printouts at each corner of the classroom.
• See the Wave Printouts attachment for example images.
• Videos can be found on YouTube. For example, some instrumental tracks:
• Gamma waves: https://www.youtube.com/watch?v=jgk0xtM7KN8
• Beta waves: https://www.youtube.com/watch?v=-EsjpqszZY4
• Alpha waves: https://www.youtube.com/watch?v=jMeDA3UbTFU
• Theta waves: https://www.youtube.com/watch?v=O0dEQ10GpLo
• Delta waves: https://www.youtube.com/watch?v=UUnQSc_2Ew0
• Review the Jupyter Notebook Teachers’ Guide and have students complete the tutorial before class.
• Make sure your students have access to a Google account—they will need this to access Google Colab.
• Have the notebook (AnalyzeBrainWaves_NOTEBOOK.ipynb) opened and ready before class.
• Make sure students have access to EEG_Example1.csv and EEG_Example2.csv. For example, these files can be added to a shared Google Drive folder.

With the Students

1. What are Brain Waves?

   

• Distribute copies of the What is a Brain Wave? Worksheet.
• Teacher will briefly introduce the brain and brain waves using the What is a Brain Wave? Presentation.
1. Slide 2: Ask students about each wave characteristic and how it’s measured.
2. Slide 4: Point out the different types of waves on the image and briefly explain how the spectrum increases in energy and frequency from right to left.
3. Slide 6: Refer to Slide 4 and point to where the brain delta wave lies on the spectrum (far right of spectrum).
4. Slide 7: Refer to Slide 4 and point to where the brain theta wave lies on the spectrum (far right of spectrum).
5. Slide 8: Refer to Slide 4 and point to where the brain alpha wave lies on the spectrum (far right of spectrum).
6. Slide 9: Refer to Slide 4 and point to where the brain beta wave lies on the spectrum (far right of spectrum).
7. Slide 10: Refer to Slide 4 and point to where the brain gamma wave lies on the spectrum (right side of spectrum).
8. Slide 11: Briefly review the five types of brain waves and their differences—ask students to summarize each type of wave.
• This activity includes a video activity, “What Do Different Brainwaves Mean?” – https://www.youtube.com/watch?v=gvpuOBezW0w, Also linked in the What is a Brain Wave? Worksheet. This video will expand upon the material in the slides. The video will go through the five types of brain waves and explain how these brain waves characterize specific brain states and even some brain injuries/abnormalities. The activity contains questions that require students to fill-in-the-blank and true/false questions to get students to engage with the video content.
• Then student’s after gaining knowledge will practice by a combination of musical chairs and four corners. Optional: Let students briefly listen to a few seconds of the music representing each brain wave.
1. Have students stand in a central area of the room. Play one of the music clips. Then students will listen to each sound and try to run to that poster.

2. Analyzing Brain Waves?

   

• After student’s have learned about brain waves is now that they will introduce into frequencies. Teacher will go over slides.
• Analyze Brain Waves Presentation can be combined to include some examples of diagnosis:
• Slide 2: Ask students to summarize the different types of waves
• Slide 5: Ask students to picture “adding” the pink signals in the figure to create the black signal

1. Make sure to check for understanding—this is a difficult concept to follow!
2. Clarify that sinusoid, signal, and wave are synonyms used interchangeably

• Slide 7: This GIF shows different waves/signals on the left, and their component frequencies on the right in a bar plot
• Slide 8: This GIF shows students what taking a live EEG looks like—they do not need to memorize anything about this, just show them how complex a raw EEG is

1. The left side shows 8 different waves, each of which corresponds to a different part of the brain
2. The upper right shows a continuous plot of the FFT of each of the 8 waves from the left side (compare this plot to the bar plots from Slide 7)
3. The bottom right shows a heat map of the head, showing darker coloring where there is more activity in the brain

• Slide 10: Note that the plot is showing the frequency on the x-axis—NOT time

1. Mention that the power is shown in units of decibels, and this means that each “step” in the y direction moves up by a power of ten, not by a constant number

• Slide 12: This GIF shows students how a filter may tune out all components of a signal we are not interested in
• (Application Slide)

1. Slide 13: Ask students about the image shown comparing a healthy EEG with a seizure EEG—what differences do they notice?

• Then students will get to practice identifying frequencies and abnormalities by using python.
• This activity includes a Jupyter Notebook activity that will allow students to use pre-written Python code to analyze two brain wave datasets (EEG_Example1.csv and EEG_Example2.csv). The activity contains step-by-step instructions for running the code in the notebook and will ask students to interpret some of the plots created by the code.

1. Hand out the Analyzing Brain Waves Jupyter Notebook Worksheet to students—you may have students either work alone or in small groups of 2-4 students.
2. Before sending students to work on the activity, walk them through opening the notebook in Google Colab. There are directions in the activity if students need additional help.
3. After class, grade the activities and record the students’ scores in a gradebook.

• While students are playing around with Python, there could also be frequencies that have abnormalities so that students are able to identify them and gain knowledge of how doctors diagnose.
• To include the design process, ask students to consider the following question: How would you design a device to record frequencies and diagnose them?
• Have students brainstorm in groups, and then research the question based on what they know. Guide students to research engineering that allows professionals to better understand how waves work.

1. Ideas for design do not have to include only biomedical engineering. Since waves are applicable to a broad range of engineering applications, students can find ways that waves are applied in a variety of disciplines.  

• Tell students: Congratulations! You now have a better understanding of the different types of brain waves and their associated frequencies and brain states. Understanding these types of brain waves is important to the fields of medicine, neuroscience, and bioengineering. These different brain waves characterize how you’re feeling at this very moment—whether you’re deeply relaxed or extremely focused on work or a game! This ability to analyze the connection between frequency and energy of waves is very valuable across several STEM disciplines.

Vocabulary/Definitions

alpha wave: An electrical signal produced by the brain while the subject is relaxed.

beta wave: An electrical signal produced by the brain while the subject is mentally active.

brain: Control center of the central nervous system of an animal located in the skull which is responsible for perception, cognition, attention, memory, emotion, and action.

delta wave: Brain wave with a frequency of ~0.2 hertz – 3 hertz.

electroencephalogram (EEG): Recording of electrical brain activity (brain waves) made by an electroencephalograph.

electromagnetic energy: The potential energy of an electric or magnetic field.

energy: Quantity that denotes the ability to do work and is measured in a unit dimensioned in mass × distance²/time² (ML²/T²) or the equivalent.

entrainment: Alignment of an organism's circadian rhythm to an external rhythm in its environment.

epilepsy: Medical condition in which the sufferer experiences seizures (or convulsions) and blackouts.

frequency: The quotient of the number of times n a periodic phenomenon occurs over the time t in which it occurs: f = n/t.

gamma wave: Pattern of neural oscillation in humans, with a frequency between 25 and 100 Hz.

lesion: Wound or injury.

seizure: Sudden attack or convulsion, (e.g. an epileptic seizure).

theta wave: A type of electrical activity in the brain; a brain wave with a frequency of 4-8 hertz.

Assessment

Pre-Activity Assessment

Wave Review: Lead students in a short discussion to review waves and their properties (frequency, amplitude, and period). Have students list all the places they could encounter waves in their daily lives. Students might mention sound waves, light waves, waves in water, microwaves, etc.

Activity Embedded (Formative) Assessment

Wave Worksheets: Have students complete two worksheets throughout the activity: What is a Brain Wave? Worksheet and Analyzing Brain Waves Jupyter Notebook Worksheet.  

Post-Activity (Summative) Assessment

Waves and Engineering: Have students relate the activity back to engineering by discussing how an understanding of waves is important to various fields in STEM (e.g., medicine, neuroscience, bioengineering, electrical engineering, etc.).  

Activity Extensions

• To create the EEG example data used in the Jupyter Notebook activity, we used the OpenBCI classroom EEG measurement kit. This kit may be purchased and used to measure and examine students’ (and teachers’) brain waves. 
• Optional: If there’s time, have teams of 2-4 students go to Google and find an example of one of the different types of brain waves (you may either assign each team one of the five types, or have them choose their own). Then, as a class, have each team take turns showing the class their wave, and have the other teams try and guess which kind of wave it is. Keep score of all the teams’ correct guesses—the team with the most points wins.

Additional Multimedia Support

• ScienceDirect has a great article on the five types of brain waves, and they have a nice diagram comparing the five waveforms with one another: https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/brain-waves
• TeachEngineering has a unit on Creative Engineering Design that could extend on students’ exposure to the engineering design process in this activity.
• Have students complete some basic Python tutorials to become more familiar with the Python code used in the Jupyter Notebook: https://www.learnpython.org/

Copyright

Contributors

Supporting Program

Acknowledgements

This content was developed by Research Experiences for Teachers in Neural Engineering, College of Engineering at the University of Missouri under National Science Foundation RET grant no. 1801666. These contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.