We are a community of researchers, engineers, artists, scientists, designers, makers, and more. The one thing we all have in common? We share an unfaltering passion for harnessing the electrical signals of the human brain and body to further understand and expand who we are. As our community continues to grow, so does the range of possibilities of what we can discover and create. What can we build together?</div>
OpenBCI stands for open-source brain-computer interface (BCI). The <a https://openbci.myshopify.com/collections/frontpage/products/openbci-8-bit-board-kit" target="_blank">OpenBCI Board</a> is a versatile and affordable bio-sensing microcontroller that can be used to sample electrical brain activity (EEG), muscle activity (EMG), heart rate (EKG), and more. It is compatible with almost any type of electrode and is supported by an ever-growing, open-source framework of signal processing applications. Check out <a href="https://github.com/OpenBCI" target="_blank">our Github repos</a> to learn more about the OpenBCI SDK, firmware, and various ongoing projects. Check out ourhttp://docs.openbci.com
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As humans, the biggest challenges we face in understanding what makes us who we are and the greatest advancements we'll make while deciding what we become, will not be solved by a single company, an institution, or even an entire field of science. These discoveries will only—and should only—be made through an open forum of shared knowledge and concerted effort, by people from a variety of backgrounds. We work to harness the power of the open source movement to accelerate ethical innovation of human-computer interface technologies.</div>
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GETTING STARTED W/ OPENBCI
I. WHAT YOU NEED
OpenBCI Contents
OpenBCI board
OpenBCI Dongle
OpenBCI Electrode Starter Kit (ESK) or your own electrodes (not pictured)
6V AA battery pack & (x4) AA batteries (batteries not included)
(x4) plastic feet for board stabilization
1. Your Board
OpenBCI 8bit TopThis tutorial can be followed if you are working with any OpenBCI board (8bit, 32bit, or 32bit with Daisy). I’ll be working with the 8bit board.
2. Your OpenBCI USB Dongle
OpenBCI DongleThe OpenBCI USB Dongle has an integrated RFDuino that communicates with the RFDuino on the OpenBCI board. The dongle establishes a serial (if you’re working on a MAC) or COM (if you’re on PC or Linux) connection with your computer with its on-board FTDI chip. You’ll be connecting to this serial port from the OpenBCI GUI or whatever other software you want to end up using to interface your OpenBCI board.
3. Your Electrode Starter Kit (ESK) Or Other Electrodes
Electrode Starter KitIf you ordered an Open BCI Electrode Starter Kit, it should come with:
10 passive, gold cup electrodes on a color-coded ribbon cable
4oz Jar of Ten20 conductive electrode paste
TouchProof AdapterIf you plan to work with your own electrodes, the touch-proof adapter may come in handy. It will convert any electrode that terminates in the industry-standard touch-proof design to an electrode that can be plugged into OpenBCI!
4. Your 6V AA Battery Pack & 4 AA Batteries
Battery ConnectionBoth the 8bit board and the 32 bit boards have specific input voltage ranges. These input voltage ranges can be found on the back-side of the board, next to the power supply. BE VERY CAREFUL to not supply your board with voltages above these ranges, or else you will damage your board’s power supply. For this reason, we recommend that you always use the battery pack that came with your OpenBCI kit.
5. (x4) Plastic Feet
Plastic FeetYour OpenBCI kit comes with 4 plastic feet that can be snapped into the holes of your board to provide extra stability while working.
II. DOWNLOAD/RUN PROCESSING & THE OPENBCI GUI CODE
1. Download Processing for your operating system
Processing IDEBefore I continue, note that you don’t need to write any code for this tutorial, though you will see all of the code that makes the OpenBCI GUI run! First, go to the Processing Downloads page and download the latest stable release for your operating system. Processing is an open source creative coding framework based on Java. If you are familiar with the Arduino environment, you’ll feel right at home; the Processing IDE is nearly identical. If not, no worries! Once it’s finished downloading, unzip it and place the Processing .app or .exe where you typically place your applications or programs. For more information on Processing or for debugging the steps in the next section, check out the Processing Tutorials page.
2. Download the OpenBCI GUI Processing code
a. Download the necessary files & directories OR clone the OpenBCI/OpenBCI_Processing repo to your desktop (do this only if you’re familiar with Github). b. Unzip the download. It should be called OpenBCI_Processing-master after unzip/extract it. c. Locate the Processing sketchbook directory on your computer. This should have been created automatically when you installed processing. Depending on your operating system, this directory’s path is:
On Windows: c:/My Documents/Processing/
On MAC: /Users/your_user_name/Documents/Processing/
On Linux: /Home/your_user_name/sketchbook/
Note: this directory should be called “Processing” on Windows and Mac, and “Sketchbook” on Linux. This directory should already have a subdirectory called “libraries.” If it does not, create the subdirectory. d. Now, from the OpenBCI_Processing-master directory that you downloaded and unzipped in parts (a) and (b) above, copy the OpenBCI_GUI directory and paste it in the Processing sketchbook directory that you located in part (c) above. e. Finally, copy the controlP5 & gwoptics directories from OpenBCI_Processing-master/libraries and paste them into the libraries directory of your Processing sketchbook. f. Now everything is where it should be!
3. Open Processing & launch the OpenBCI GUI
a. If Processing is currently open, close it. The new libraries you added won’t be recognized until you restart the application.Processing IDEb. Double-click any of the .pde files in the OpenBCI_GUI directory and all of the OpenBCI GUI code should open in the Processing IDE, as seen on the right.Play Buttonc. Click the “run” button on the top left of the IDE, and the code should run! If it does not, make sure you installed your libraries correctly and that are using the latest version of Processing. If you continue to have issues, please refer to the software section of our forum for help.Syntheticd. Once the GUI is running, select “SYNTHETIC (algorithmic)” and hit the “START SYSTEM” button to launch the GUI with a synthetic data generator.Start Data Streame. Click the dark overlay on the GUI to exit the SYSTEM CONTROL PANEL and then hit the “Start Data Stream” button to begin the stream of synthetically generated EEG data. You should then see data streaming across the “EEG Data” graph on the left side of the GUI.
III. PREPARE YOUR OPENBCI HARDWARE
1. Make sure your FTDI drivers are installed and up-to-date
FTDI InstallThe FTDI chip on your OpenBCI Dongle requires you to install the FTDI drivers on your machine. You may already have these installed, if you’ve worked with Arduino or other USB hardware accessories. You can download the latest FTDI drivers for your operating system here. Note: you may need to restart your GUI for this to take effect.Unidentified Developer MACIf using a MAC: When you try to install the FTDI driver, your computer may tell you that it is unable to install the application because it is from an unidentified developer. In this case, go to System Preference > Security & Privacy and switch your settings to “Allow Applications Downloaded from: Anywhere,” as seen in the screenshot to the right. You will most likely have to unlock the lock (and type in your root password) at the bottom of the Security & Privacy window before you can make this change.
2. Plug in your OpenBCI USB Dongle
Dongle ConnectionPlug this in (facing upwards!) and you should see a blue LED light up.Note: make sure your USB Dongle is switched to GPIO 6 and not RESET. The switch should be set closer to your computer as seen in the picture to the right.
3. Plug in your 6V AA batter pack (with batteries)
Battery ConnectionBoth the 8bit board and the 32 bit boards have specific input voltage ranges. These input voltage ranges can be found on the back-side of the board, next to the power supply. BE VERY CAREFUL to not supply your board with voltages above these ranges, or else you will damage your board’s power supply. For this reason, we recommend that you always use the battery pack that came with your OpenBCI kit. There’s a good reason we put this notice in here twice!
4. Switch your OpenBCI board to PC (not OFF or BLE)
Power Up BoardMake sure to move the small switch on the right side of the board from “OFF” to “PC”. As soon as you do, you should see a blue LED blink 3 times. You don’t press the reset button just to the left of the switch. If the LED still does not blink 3 times, make sure you have full battery. If you’re sure your batteries are fully charged, consult the hardware section of our Forum.Note: it’s important to plug in your Dongle before you turn on your OpenBCI board. Sometimes, if the data stream seems broken, you may need to unplug your USB Dongle and power down your OpenBCI board. Make sure to plug your USB Dongle in first, then power up your board afterwards.
IV. CONNECT TO YOUR OPENBCI BOARD FROM THE GUI
1. Relaunch your OpenBCI GUI
You may need to relaunch the OpenBCI GUI after installing the FTDI drivers.
2. Select LIVE (from OpenBCI)
Select LiveIn order to connect to your OpenBCI, you must specify the data source to be “LIVE (from OpenBCI)” in the first section of the SYSTEM CONTROL PANEL. Before hitting the START SYSTEM button, you need to configure your OpenBCI board (follow the steps below).
3. Find your USB Dongle’s Serial/COM port
Select SerialIn the first section of the LIVE (from OpenBCI) sub-panel, find your Dongle’s Serial/COM port name. If you’re using a MAC, it’s name will be in the following format:/dev/tty.usbserial-DNxxxxxxIf you’re using Windows or Linux, it will appear as:COM#Your USB Dongle’s port name will likely be at the top of the list. If you don’t see it:
Make sure your dongle is plugged in and switched to GPIO 6 (not RESET)
Click the REFRESH LIST button in the SERIAL/COM PORT section of the sub-panel
Make sure you’ve installed the latest FTDI drivers, as described in section III.1
If you’re still having trouble finding your USB Dongle’s port name, refer to the Forum about debugging your hardware connection.
4.(optional) Edit the Playback file name
File NameIn the DATA LOG FIlE section of the LIVE (from OpenBCI) sub-panel you can specify the name of your playback file. This file name is automatically defaulted to:SavedData\OpenBCI-RAW- + date/timeYou can edit the the name of this file by clicking in the “File Name” text field.If you’re running the OpenBCI GUI from Processing. This file will be saved at the root of your OpenBCI_GUI directory. If you’re running the OpenBCI GUI as a standalone application, this file will be saved in /Contents/Java/Data/EEG_Data/If working from a Mac, you’ll need to right-click on the OpenBCI_GUI application and then select “show package contents” to see the /Contents directory where your playback files are saved.After creating a Playback file, it can be replayed by running the OpenBCI GUI with the Plaback File data source mode. As a result, you can easily share recorded OpenBCI Playback files with your friends and colleagues.
5 Select your channel count (8 or 16)
Channel CountThe CHANNEL COUNT setting is defaulted to 8. If you are working with an OpenBCI Daisy Module and 32bit board (16-channel) system, be sure to click the 16 CHANNELS button before starting your system.
6. Select your SD setting
WRITE TO SDIf you want to log data to a MicroSD inserted into the OpenBCI Board, in the WRITE TO SD (Y/N)? sub-panel section you can select the maximum recording time of the file. This setting is defaulted to “Do not write to SD…” and will automatically switch to this if you do not have a MicroSD card properly inserted into your OpenBCI Board.Note: be sure to select a file size that is larger than your planned recording time. The OpenBCI writes to the local SD in a way that enables us to write lots of data very quickly. As a result, however, we must specify how large the file will be before we begin. The technique is known as block writing.
7. Press “START SYSTEM”
START SYSTEMNow you’re ready to start the system! Press the START SYSTEM button and wait for the OpenBCI GUI to establish a connection with your OpenBCI Board. This usually takes ~5 seconds. InitializingDuring this time, the help line at the bottom of the OpenBCI GUI should be blinking the words: “Initializing communication w/ your OpenBCI board.”TROUBLESHOOTINGIf the initialization fails, try the following steps in order:
Making sure you’ve selected the correct serial/COM port
Power down your OpenBCI board and unplug your USB Dongle. Then, plug back in your USB Dongle and power up your OpenBCI board in that order. Then try restarting the system, but pressing the START SYSTEM button again.
If this does not work, try relaunching the OpenBCI GUI application and redo step 2 above. Then reconfigure the SYSTEM CONTROL PANEL settings, and retry START SYSTEM.
Make sure that your batteries are fully charged and then retry the steps above.
If you are still having troubles connecting to your OpenBCI board, refer to the Forum for extra troubleshooting advice.
8. Your OpenBCI is now live!
Start StreamOnce the GUI successfully connects to your OpenBCI Board, click anywhere outside of the SYSTEM CONTROL PANEL to access the rest of the features of the GUI.You can now press the bright green Start Data Stream button (located at the top middle of the GUI) to begin streaming live data from your OpenBCI board.TouchTo make sure that it is responsive, (after you’ve started the data stream) try running your fingers along the electrode pins at the top of your board. ChaosYou should see the 8 (or 16 if you’re using a Daisy module) channels on the EEG DATA montage behave chaotically in response to you touching the pins. The headplot on the right side of the GUI should become fully saturated (turning bright red) when you do this. And all the tracess of the FFT graph on the lower right should instantly shift upwards.If this is the case, congratulations; you are now connected to your OpenBCI board. It’s time to see some brain waves!
V. CONNECT YOURSELF TO OPENBCI
In this quick demo, we’ll be showing you how to set up 3 channels of electrophysiological data that reveal your heart activity (EKG or ECG), muscle activity (EMG), and brain activity (EEG)!For more information on these three signals, refer to wikipedia:
Heart Acitivity - Electrocardiography (EKG or ECG)
Muscle Acitivity - Electromyiography (EMG)
Brain Activity - Electroencephalography (EEG)
1. What you need
What You NeedNecessary:
Ten20 conductive elctrode paste (or other conductive electrode gel)
Your OpenBCI board, USB Dongle, battery pack, and x4 AA batteries
x6 gold cup electrodes (from your OpenBCI electrode starter kit or other). If you are using an OpenBCI electrode starter kit, use the following electrodes so as to be consistent with the GUI’s color-coding protocol:
Black
White
Purple
Green
Blue
Red
Optional:
Paper towels for cleaning excess Ten20 paste
Medical tape (or other tape) for adding extra stability to electrodes
Ear swabs for cleaning paste from electrodes, once you’re finished
2. Connect your electrodes to OpenBCI
Electrode Connections 1
Connect the white electrode to the SRB2 pin (the bottom SRB pin). The SRB2 pin is the default “reference pin” for your OpenBCI input channels.
Connect the black electrode to the bottom BIAS pin. The BIAS pin is similar to the ground pin of common EEG systems, but it uses destructive interference waveform techniques to eliminate the “common mode noise” of all of the active channels.
Connect the purple electrode to the 2N pin (the bottom pin of the N2P input)
Connect the green electrode to the 4N pin (the bottom pin of the N4P input)
Connect the blue electrode to the 4P pin (the top pin of the N4P input)
Connect the red electrode to the 7N pin (the bottom pin of the N7P input)
Electrode Connections 2Basic OpenBCI pin overviewThe picture to the right is a perspective view of the electrode inputs that we are working with in this tutorial. The bottom pins are (N) inputs, and the top pins are (P) inputs. The default board settings look at all N channels in refernce to SRB2 (the bottom SRB pin). SRB1 (the top SRB pin) can also be used as a reference, but when it is activated, it is activated for ALL channels. If using SRB1 as the reference electrode, P inputs must be used as the other input of the potential difference measurement. On the contrary, individual channels can be removed from SRB2. If a channel is removed from SRB2, it can be examined as a unique voltage potential, between the N and P pins of that channel. We will be doing this for the heart measurement in this tutorial, while examining 2 EEG channels in reference to SRB2, using the channel 2 and 7 N pins. For more information on this, refer to page 16 of the ADS1299 datasheet. The ADS1299 chip is the analog front-end at the core of the OpenBCI board.
3. Connect your electrodes to your head and body
Electrode Pastea) We’re going to start with the electrodes on your head. Begin by scooping Ten20 electrode paste into your white gold cup electrode. This is going to be your reference (or SRB2) electrode for the other electrodes on your head. Fill the electrode so there is a little extra electrode paste spilling over the top of the gold cup, as seen in the picture to the right. Note: Use a paper towl or napkin to remove excess electrode paste as you are applying your electrodes.SRB2b) Now apply this electrode to either one of your earlobes (either A1 or A2 as seen on the 10-20 system image below). You can use some medical tape (or electric tape!) to give this electrode some extra stability, ensuring that it does not fall off. This electrode is the reference that all of the EEG electrodes on your head will be measured in comparison to. The uV reading that will appear in the GUI’s EEG DATA montage is a measure of the potential difference between each electrode and this reference electrode (SRB2). SRB1 (the top SRB pin) can also be used as a reference pin, but we won’t discuss that here. Check out the other docs on how to maximize the usage of the other pins!Fp2c) Follow the same procedure for the purple electrode and apply it to your forhead 1 inch above your left eyebrow (as if you were looking at yourself) and an inch to the left of your forheads centerline. 1020This electrode location is Fp2 on the 10-20 System. The 10-20 System international standard for electrode placement in the context of EEG. Fp indicates the a “frontal polar” site.O1d) Now follow the same procedure for the red electrode and place it on the back of your head, 1 inch above the inion (as seen on the 10-20 system), and 1 inch to the left. This electrode location is O1 on the 10-20 system. The ‘O’ stands for occiptal, meaning above your occipital lobe (or visual cortex).Note: to do this, pull your hair aside and make sure the electrode is nested as deeply as possible, with the electrode paste making a definitive conductive connection between your scalp and the gold cup.headbande) Now follow the same procedure as step 2 above to apply the black electrode to your other earlobe (either A1 or A2 from the 10-20 system). The black electrode is connected to the BIAS pin, which is used for noise cancelling. It is similar to a GROUND pin, which establishes a common ground between the OpenBCI board and your body, but it has some extra destructive interference noise cancelling techniques built in! You’re now done connecting electrodes to our noggin! I like to use a cheap cotton hairband to add extra stability to all of the electrodes connected to my head, by placing it gently on top of all of the electrodes. forearmf) Now connect the green electrode to your right forearm, somewhere on top of a muscle that you can flex easily. With this electrode we will be looking at both heart activity and muscle activity. I also like to use tape to hold this electrode in place. That’s going to hurt a little bit to take off. Hopefully your arms aren’t as hairy as mine…wristg) Finally, connect the blue electrode to your wrist on the opposite arm with the green electrode. This will serve as the reference electrode for the blue electrode. If you noticed, the blue electrode is on the pin above the green electrode. We will be removing pin 4 from SRB2 so that it is not included in the same reference signal being used to measure brain waves. The main reason for this is because the microvolt (uV) values produced by your heart and muscles are much stronger than the signals we can detect from your brain, so we don’t want these signals to interfere. I’ll go into more detail about this later on, when it comes time to adjust the channel settings in the GUI.
4. Launch the GUI and adjust your channel settings
a) If your OpenBCI GUI is not already running, relaunch it and configure the DATA SOURCE mode to LIVE (from OpenBCI). Refer to section IV of this guide for more information on this process. Since we are only using 3 channels, set the channel count to 8, even if you have a daisy system. Nothing will go wrong if you start the system with 16 channels, except the EEG DATA montage will be unnecessarily cluttered.b) Once you have pressed START SYSTEM and the GUI has connected to your OpenBCI device, exit the SYSTEM CONTROL PANEL and start the live data stream. You should see live data from your body (and the unattached channels) streaming into the EEG DATA montage on the left side of the GUI.Power Downc) Now we are going to power down the channels we aren’t using. Do this by clicking the channel number buttons outside of the left side of the EEG DATA montage. We are only using channels 2, 4, and 7, so power down every other channel. Don’t bother with the smaller dark grey squares to the right of the buttons with numbers; they are used for impedance measuring, but we won’t go into that now. You can also power down the channels with keyboard shortcuts (1-8). Power them back up with [SHIFT] + 1-8. If you are working with a daisy module, channels 9-16 can be powered down with q, w, e, r, t, y, u, i, respectively. You can power those channels back up with [SHIFT] + the same key. Signals At Startd) Now that you have powered down channels 1, 3, 5, 6, and 8, your EEG DATA montage should look similar to the screenshot on the right (after you relax and let the system settle).Adjust Channel Settingse) Now it’s time to optimize your OpenBCI board’s channel settings for this setup. Click the CHAN SET tab to the right of the EEG DATA tab, and an array of buttons should appear of the EEG DATA montage. These buttons indicate the current settings of the ADS1299 registers on your OpenBCI board. For more information on these settings, refer to pages 39-47 of the ADS1299 datasheet.We have simplified the interface through the OpenBCI firmware and OpenBCI GUI to allow easy, real-time interaction with these registers. For more information on this, please refer to our doc page regarding the ADS1299 interface.By deactivating channels 1, 3, 5, 6, and 8, those channels were automatically removed from the BIAS and SRB2, so as not to interfere with the signal. The only thing left to do is update channel 4, the input we are using for EMG and EKG. Begin by clicking the PGA Gain button for channel 4 until it is set to x8. Then remove it from the BIAS and SRB2. The reason we do this is because the uV values for EMG and EKG are much bigger (and easier to pick up) than the EEG signals on channels 2 and 7. As a result, we want to prevent channel 4 from influencing the common mode noise rejection of the BIAS, as well as remove it from the EEG reference channel (SRB2).EEG DATA AFTER ADJUSTING SETTINGSf) After updating these settings, click the EEG DATA tab again, and your EEG DATA montage should now appear similar to the image on the right. Notice that you no longer see the heart beat artifacts in channels 2 and 7. Additionally, the heart beat signal in channel 4 should be more steady, looking more like a typical EKG signal.
5. Minimizing noise
So there’s a good chance your current setup isn’t showing clean data like the screenshots above. There are a number of possible reasons for this. We’ll go through troubleshooting them here.Notch FilterGet rid of AC noiseGet rid of 60 Hz (or 50 Hz if you’re in Europe or any country that operates on a 50 Hz power grid). The OpenBCI has a built-in notch filter, that does a decent job at eliminating 60 Hz noise. You can adjust the notch filter to 50 Hz by clicking the “Notch 60 Hz” button. Additionally, if your OpenBCI board is on a table with any power chords or devices that are plugged into a wall outlet, move it to a location away from any electronic devices plugged into the wall. This will drastically reduce the alternating current (AC) influence on your signal.Stablize Your Cables w/ TapeStablize your electrodesMake sure your electrode cables are steady. If you shake the electrodes that are dangling from your head/body, you’ll notice that it severely affects the signals. This movement noise is something that could be greatly improved with “active” electrodes, but when using the “passive” electrodes that come with the OpenBCI electrode starter kit, you have to be very careful to remain steady while using the system, in order to produce the best signal. Sometimes, I’ll bind all of the electrode cables together with a piece of electric tape to secure them and minimize cable movement. If you do this, don’t worry about including the blue and green electrodes in the bundle, since movement noise doesn’t affect the EMG/EKG signal as significantly.Ensure that your electrodes are securely conncetedEnsure that your electrodes are connected securely (especially your reference)!Make sure your OpenBCI hardware is streaming data properlyEvery so often, an error will occur with the wireless communication between your OpenBCI Dongle and board. If you’ve followed all of the steps above, and the data that you are seeing in the GUI interface is still illegible, try the following:Power down your OpenBCI board and unplug your USB Dongle. Then, plug back in your USB Dongle and power up your OpenBCI board in that order. Then try restarting the system, but pressing the START SYSTEM button again.Further troubleshootingIf you’re still having issues, refer to the Forum for further troubleshooting techniques.
VI. CHECK OUT YOUR BODY’S ELECTRICAL SIGNALS!
Congratulations! If you’ve made it this far, it’s finally time to check out your body’s electrophysiological signals!
1. Check out your heart activity (EKG)
Heart BeatChannel 4 in the GUI should now be producing a nice steady succession of uV spikes. This is your heart beating! Try taking slow, deep breaths and watch how it influences your heart rate. If you look carefully, you may notice your heart beat more rapidly as your inhaling, and more slowly as you’re exhaling.Analyzing EKGFor more information on how to analyze an electrocardiography (EKG) signal, or on how to set up a full EKG (with 10 electrodes), check out the wikipedia page on EKG. The image to the right (pulled from the Wikipedia page) shows the various segments of a single heart beat.
2. Watch your muscles flex (EMG)
Forearm FlexNow, try flexing your forearm or whatever muscle you placed the green electrode on top of. You should see a high-amplitude, high-frequency signal introduced into channel 4. This is the electric potential created by you activating your muscle!If you relax your muscle again, you should see the channel 4 signal return to your heart beat (just EKG). The picture on the right shows this transition. When you’re flexing your muscle, the electrode is picking up EMG and EKG at the same time. After you relax your muscle, the high-frequency signal disappears, and you’re able to see just EKG.
3. Eye blinks and jaw clenching (more EMG)
Eye Blink & Jaw Clench EMG ArtifactsNow blink your eyes a few times. Each time you blink you should see a strong spike on the EEG DATA montage. It should be most visible in channel 2, the channel for the electrode directly above your eye! This uV spike is a result of the muscles in your forehead that make your eyes blink.Now try clenching your jaw. You should see a big uV spike in both channels 2 and 7. Each time you clench your jaw, you are introducing a strong EMG artifact into any electrodes on your scalp. If you put your fingers on the side of your head (above your ear) and clench your teeth, you should be able to feel the muscles in your head flexing.In the photo to the left, you can see what these signals look like the green highlighted region shows a single eye blink. The two blue sections show an extended period of jaw clenching.It’s interesting to note that these signals are not picked up in channel 4. This is because channel 4 is only looking at the potential difference across your body—from your right forearm to your left wrist. As a result the EMG/EEG artifacts being produced on your head (in reference to SRB2) are not visible in this channel.
4. Brain waves (alpha) with OpenBCI!
Alpha Brain Waves!Now, for what we’ve all been waiting for… let’s check out some brain waves! Firstly, deactivate channel 4 so that you are only looking at the EEG channels (2 and 7).It’s best to do this portion of the tutorial with a friend. You’ll understand why in a second. It just so happens that the easiest way to consciously produce brain waves is by closing your eyes. When you do this, your occipital lobe (the part of your brain responsible for processing visual information) enters into an alpha wave state at a frequency between 7.5-12.5 Hz. Alpha brain waves are the strongest EEG brain signal! Historically, they are thought to represent the activity of the visual cortex in an idle state. An alpha-like variant called mu (μ) can be found over the motor cortex (central scalp) that is reduced with movement, or the intention to move [Wikipedia].For more information on Alpha waves check out Wikipedia and Chip’s EEG Hacker blog post about detecting alpha waves with OpenBCI V3.Once you’ve closed your eyes, have your friend press the ‘m’ key on your keyboard to take screenshots. Tell him or her to wait until a strong alpha spike emerges on the Fast Fourier Transform (FFT) Graph, the graph in the lower-right of the GUI. The spike should be somewhere between 7.5-12.5 on the the x-asix of the FFT graph, indicating that there is a strong presence of waves in that frequency range.After you’ve taken a few good screenshots, open up the .JPGs and take a look. Note: the screenshots are located in the root directory of your application, or in the OpenBCI_GUI directory if you are working from Processing. You’ll notice that the strongest alpha wave signals should be appearing in channel 7, the O2 (O standing for occipital) electrode on the back of your head. Count the number of waves in a single 1-second time period on channel 7 of the EEG DATA montage. The number of waves should correspond x-axis position of the spike on the FFT graph. If you’ve identified your alpha waves, congratulations! You’ve now seen your first brain waves with OpenBCI!
5. What’s next?
For more ideas on what to do next, check out Chip’s Blog EEG HACKER and the other OpenBCI Docs pages.Also, if you have a great follow-up tutorial to this getting started guide or something else you want to share, feel free to create your own by following format we have in the Docs repo of our Github. It’s really easy to create your own Docs page with a Markdown editor like Mou. If you do so, send us a pull request on Github and we’ll add your tutorial to the Docs! If you have troubleshooting questions be sure to visit the OpenBCI Forum. For all other inquiries, contact us at contact@openbci.com.
http://www.openbci.com
