I’d like to understand the best way to calculate the Theta /
Beta ratio with Mind Monitor. I’m new to EEG analysis and have some basic neuroscience questions.
In this https://journals.sagepub.com/doi/full/ ... de%20site. paper, ADHD is measured by the absolute power of bands at each site.
I don’t quite understand the difference between absolute and raw data for each dry electrode site. I was under the impression that each brain region has a unique power output at any given time. And this unique power is classified into power bands (delta,
beta, etc.).
But, mind monitor has a setting to record both raw data (a unique power output per site) and an absolute measure, where each powerband (theta, beta, alpha, etc) is measured at each site simultaneously.
What is Mind Monitor calculating when it outputs, for example, both Theta, Beta and Raw at AF7? i’ve tried to read tutorials but can’t find an answer. what does it mean for AF7 to be in both Theta and beta simultaneously?
If I wanted to calculate the theta/Beta ratio similar to the academic paper above, would I use the absolute or raw power band output, averaged over each site?
I hope this question made sense and please let me know if I can make it to be more clear.
thank you
https://journals.sagepub.com/doi/full/1 ... ode%20site.
Theta / beta ratios and basic eeg
Re: Theta / beta ratios and basic eeg
RAW EEG is voltage data. This is processed via FFT to give you power spectral density per frequency and these are grouped together into frequency sets, Alpha, Beta etc.
To calculate a Theta/Beta ratio, you can just take Theta Absolute divided by Beta Absolute, that's it.
Each wave has a value per sensor, so if you want to indivdually work out your ratio per locaction e.g Theta_AF7/Beta_AF7 would just be the ratio for AF7. Or for a single value take the average Theta for all four locations and divide that by the average Beta for all four locations.
The only time you want to use RAW EEG data is when you're doing your own FFT's to calcualte power at a specific indivdual frequency, or do your own filtering.
To calculate a Theta/Beta ratio, you can just take Theta Absolute divided by Beta Absolute, that's it.
Each wave has a value per sensor, so if you want to indivdually work out your ratio per locaction e.g Theta_AF7/Beta_AF7 would just be the ratio for AF7. Or for a single value take the average Theta for all four locations and divide that by the average Beta for all four locations.
The only time you want to use RAW EEG data is when you're doing your own FFT's to calcualte power at a specific indivdual frequency, or do your own filtering.