Frequency Bands

How to view frequency information

Frequency Analysis can be found in the menu on the left-hand side of the EmotivPRO screen.

The Frequency Analysis view allows you to see frequency information of a single EEG channel.

Selecting an EEG channel

To select an EEG channel:

1. Click on the eye icon, next to Channel, at the top-right-hand corner of the screen.

2. A pop-up box will open showing the channels you can select

3. Click on the channels you want to see.

4. To close the pop-up box, click anywhere outside of the box.

Selecting a window

To select a window:

1. Click on the drop-down menu next to Window at the top right-hand corner of the screen.

2. Select either:

   • Hanning,

   • Hamming,

   • Hann,

   • Blackman, or

   • Rectangle.

Fast Fourier Transform (FFT) graph

The graph at the top of the Frequency Information view displays an FFT analysis of the selected EEG channel as dB over frequency (Hz). You can adjust the parameters using the controls on the left-hand-side of the screen.

‌The parameters include:

• amax, amin - Adjust the maximum and minimum amplitude (dB) for the y-axis

• fmax, fmin - Adjust the maximum and minimum frequency (Hz) for the x-axis

• length - Adjust the transform length for the FFT analysis

• step - Adjust the step size for the FFT analysis

Band power graph

The bar graph at the bottom of the Frequency Information view displays the power of theta (4-8Hz), alpha (8-12Hz), low beta (12-16Hz), high beta (16-25Hz) and gamma (25-45Hz) frequencies for the channel selected.

You can adjust the parameters using the controls at the bottom left-hand-side of the screen.

The parameters include:

• ‌pmax, pmin - Adjust the maximum and minimum amplitude for the y-axis

• autoscale - Automatically scale the data to fit the max value on the y-axis and update the y-axis appropriately

‌You can choose to export the time series values of these five frequency bands for each sensor on your headset when you export data. You can view the format of these files here.