How to understand the graph

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fivesenses
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Joined: Sat Nov 19, 2016 7:49 am

How to understand the graph

Post by fivesenses » Sat Nov 19, 2016 7:52 am

Hi, I'm using Muse Monitor solely for personal use and so have never seen an EEG graph in my life. I want to know when I'm entering the 7.5-8.5Hz state so I can figure out which meditation practices induce this most easily. But I have no idea how to find that out when I look at the graph. Can you give me some insight please? Thanks.

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James
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Re: How to understand the graph

Post by James » Sun Nov 20, 2016 9:33 am

To see a specific frequency, switch to the discrete frequency graph, shown below.

You can then read off values for each individual frequency. For example, the approximate 7.5-8.5Hz area is circled in red.
Muse8Hz.png
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fivesenses
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Re: How to understand the graph

Post by fivesenses » Mon Nov 21, 2016 3:16 am

Thanks for replying. So let's say I do a 20 minute session and I want to know how long I was in the theta state. How could I tell from this graph?

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James
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Re: How to understand the graph

Post by James » Mon Nov 21, 2016 8:25 am

This is a real time graph, so you would have to watch it and see ;-)
Instead switch to the spectrogram, which displays discrete frequency data plotted over time.
Use a two finger touch to adjust the maximum and minimum magnitude range values, to tweak the spectral output.

carbophoze
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Joined: Thu Sep 28, 2017 9:17 am

Re: How to understand the graph

Post by carbophoze » Thu Sep 28, 2017 9:29 am

I recorded the hour-long data and want to interpret the result correctly. Help me please.
How do I know in what state my brain was?
What is the theoretically ideal graph for the alpha state?
Thank you.
csv format
https://drive.google.com/open?id=0B3ZRC ... mNNaUgtdm8
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James
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Re: How to understand the graph

Post by James » Fri Sep 29, 2017 7:29 am

There is not really any such thing as being "in" a brainwave state. At any point in time, your brain has some activity in all brainwave frequeucies. Delta, Theta, Alpha, Beta and Gamma are names that we give to ranges of these frequencies. Alpha for example is any brain activitiy occuring between 7.5Hz and 13Hz. Since there is activity in all areas at all times, we quantify each of these brainwaves by measuring the amount of power within the range and we call this the Power Spectral Density (PSD for short). Think of this like the signal strength of an old FM radio station.

From a meditation stand point, what you should see is that your average Alpha PSD will be higher during meditation than it is during normal activity (As it appears to be in the above graph). You may also see that during meditation the other brainwaves will be lower. It is this effect that people sometimes refer to as being "in" a particular brainwave state.

carbophoze
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Re: How to understand the graph

Post by carbophoze » Fri Sep 29, 2017 8:36 am

Thanks for your reply. OK. I think I understood what is FFT. Maybe if you add a view to PSD on the site, it will be clearer for newbies. IMHO.
Thank you, great work).

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