Interpreting the site locations on Spectogram trials

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stotler
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Joined: Mon Aug 24, 2020 1:51 pm

Interpreting the site locations on Spectogram trials

Post by stotler »

Hello.

When we are analyzing the EEG through the Spectogram graphs, how do we intrepret what locations are being graphed? Must we understand the Fast Fourier Transform to understand what locations are in what frequencies, or must we understand that all of the sites are somehow averaged and dispalyed averaged in all frequency locations? It is obvious that we have the colors as frequency identifiers (in the frequency respective locations) although the graphs dispalys "AF7" and "AF8" at the top of the graph, but these sites do not seem to be clearly represented.

How to understand what sites are in what frequencies, or how do we understand where AF7 and AF8 are isolated sites (within their own frequencies) and seperately represented in the Spectogram graph application?

Thank you and please reply,
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James
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Re: Interpreting the site locations on Spectogram trials

Post by James »

The default display shows the average of the two front electrodes AF7 and AF8.
If you want to show the FFT from a single electrode, you can change this in the settings under "FFT Components".
stotler
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Re: Interpreting the site locations on Spectogram trials

Post by stotler »

Thank you James!
stotler
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Joined: Mon Aug 24, 2020 1:51 pm

Re: Interpreting the site locations on Spectogram trials

Post by stotler »

Do we know of a way to display and record two sides of the frontal lobe at the same time?
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James
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Re: Interpreting the site locations on Spectogram trials

Post by James »

If you record your session at the "Constant/256Hz" recording interval, you will get the raw eeg data for each of the four sensors. You would need to do you own FFT calculations to get a spectrogram, but the source data is there.
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