tedor

I am wondering whether someone could give me a tip how to do a [I]

], which calculates the spectral "centre of gravity" of the 

signal; that is, the midpoint of its energy distribution. It is a 

measure of the average frequency weighted by amplitude. This is 

usually averaged over time (Miranda, 2006)

I am wondering whether someone could give me a tip how to do a [I]spectral centroid analysis[/I], which calculates the spectral "centre of gravity" of the 
signal; that is, the midpoint of its energy distribution. It is a 
measure of the average frequency weighted by amplitude. This is 
usually averaged over time (Miranda, 2006)

spectral-centroid-analysis

http://crca.ucsd.edu/~tapel/software.html

you can get a look at [centroid~] :http://crca.ucsd.edu/~tapel/software.html

and [brigthness~] :http://web.media.mit.edu/~tristan/

I wonder whether someone could help me here. I used the suggested objects [centroid] and [brightness] on the EEG data. 

The centroid object gives me a spectrum central of 17.2 hz which sounds good [attached picture]... but the 17.2 hz does not change at all and is the same in both hemispheres. (Live recording.) 

I reckon this value should change at least a bit if I change my mind , but at least when I move my eyes!

http://www.mitpressjournals.org/doi/abs/10.1162/comj.2008.32.3.87

I wonder whether someone could help me here. I used the suggested objects [centroid] and [brightness] on the EEG data. 
EEG data is in 120 Sampling rate. 

The centroid object gives me a spectrum central of 17.2 hz which sounds good [attached picture]... but the 17.2 hz does not change at all and is the same in both hemispheres. (Live recording.) 
 I reckon this value should change at least a bit if I change my mind ,  but at least when I move my eyes!

ps.: I might find something in here:http://www.mitpressjournals.org/doi/abs/10.1162/comj.2008.32.3.87

Out of curiosity, wondering what hardware and communication you're using to get and read in the EEG data? It's an interest of mine and I've tinkered a bit, but haven't found anything very satisfactory yet (in ease of use or concerning accuracy). 

I am using IBVA (bluetooth, 2ch, 3 electrode + earclip = bipolar) device. The software which came with it looks reliable. Gives me the visual representation of the raw data and the spectrum as well in 3d.

http://www.youtube.com/watch?v=MPOGguC2qgo&feature=related

I would like to use the device in Max/MSP as a biofeedback device, using a power spectrum analysis and a spectral centroid analysis.

I am using IBVA (bluetooth, 2ch, 3 electrode + earclip = bipolar) device. The software which came with it looks reliable. Gives me the visual representation of the raw data and the spectrum as well in 3d. 

I would like to use the device in Max/MSP as a biofeedback device, using a power spectrum analysis and a spectral centroid analysis. 