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My EEG Frequency

By now you are familiar with Get Started with TrueSense kit, and have successfully setup and configure your TrueSense kit. You are also familiar with How to read EEG signal, this article will further help you to locate your personalized brain wave bands (particularly the Alpha (α) wave and Sigma (σ) wave bands). You can compare them to the distribution for the general population, so you know how unique you truly are. You can also enter these key numbers into your Profile, to enable more accurate analyses when using other Applets.

(The OPI Console Spectrogram starts from 1Hz, with 0.5Hz increment for each band, and with adjustable maximum frequency, so you can find Alpha (α) wave and Sigma (σ) wave frequency peaks easily.  Simply reduce the maximum display frequency to lower value, for example 16Hz, and count from bottom (1Hz) upwards to the band showing the peak in 0.5Hz increment, and write down the peak frequency value.)

Before you attach the sensor, please make sure you have configured single sensor pairing correctly.  For this session, it's best to wear the sensor around the temple (for the Star Trek Seven-of-Nine look), because you can capture more types of brain waves and muscle effects at this location.

Choose either right side or left side based on where is the USB port the controller will be plugged into, and make them the same side, so as to ensure good wireless communication between the sensor and the controller.

Start the OPI Console application, click the Live Display APP, select the sensor, and select both Main Signal and Spectrogram for viewing. (Note: even though you only select a few parameters for viewing, All of the data will be captured on memory for later upload to the PC for analyses and storage.)  If everything is setup properly, you should see signals start moving on the display.  If the signal is intermittent, adjust the orientation and angle of the controller.

Now let the fun start.

Sit comfortably in front of your PC, follow the instructions and the sequence below.

Step 1: find your EMG band: you have done this before, do a few "jaw clenchings" and you can see the large rapid spikes on the Main Signal display. Now look at the Spectrogram display, see the high frequency high intensity characteristics of jaw clenching. The high frequency end goes through the 256Hz limit, and the low frequency end spills all the way down to ~20Hz. Clench a few more times with various force, and try tightening up different facial muscles, and note the consistent power spectrum of EMG.

Step 2: find your alpha (α) wave band: Close your eyes and stay calm and quiet, relax all facial muscles and try not to think of anything.  Write down its approximate frequency from the Spectrogram.  Don't worry if you cannot detect it at this time, either you have very weak alpha wave, or you can learn to do it better later.

Step 3: find your sigma (σ) wave band (sleep spindles): Now relax totally and take a nap lying down for about 20 minutes or more.  Record your data in memory module and analyze it later. Make sure to write down your unique frequency.  Although most people have this band between 12~14Hz, some people can be up to 30Hz.

Step 4: Observe how your slow eye and facial skin movements can create artificial lower frequency bands.

Starting from high to low frequencies:

1. EMG: generally from 80~3000Hz with most energy in the higher frequency region. Caused by a lot of muscle neurons firing together.

2. Super beta (β) or Gamma (γ) wave: from 30~150Hz with most energy between 60~100Hz, associated with visual processing, problem solving and memory work.

3. Beta (β) wave: from 12~40Hz with most energy between 20~30Hz, associated with attention and fast activities.

4. Spindles or Sigma (σ) wave: generally from 12~14Hz, a burst of waves with unique spindle shaped envelope, associated with deeper sleep stages.

5. Alpha (α) wave: generally from 8~12Hz with significant variations, associated with relaxation and when eyes are closed. Certain fraction of the population have weak to undetectable alpha waves.

6. Theta (θ) wave: generally from 4~8Hz, associated with drowsiness.

7. Delta (δ) wave: generally from 0.5~4Hz, associated with deep sleep.