Dear Muhammad,
You can go back to those datasets with power and do something like:
D = spm_eeg_load('filename.mat');
data = D.selectdata('Cz', [0.3 0.5], {'Cond1', 'Cond2', 'Cond3', 'Cond4'});
Do
help meeg/selectdata
for additional explanations and more options.
Best,
Vladimir
On Wed, Apr 28, 2010 at 11:10 PM, MP <[log in to unmask]> wrote:
> Hello SPMers,
>
> I am working with an EEG dataset that has trials for 4 different
> experimental conditions. i pre-processed the data with SPM and then I
> converted the data into time-frequency domain and then averaged it for each
> condition. Then I converted these averages into image files by using
> "Convert to Image" function. In this step i averaged across a frequency band
> of interest for each channel. This step generated a folder with image files
> for each condition and an EEG file (.DAT and .MAT) with averaged frequency
> band across all the channels. After doing the statistics on the images, I
> now know the channel and the time range that I need to extract the power
> (numerical values) of the frequency band. How can I access this data? Is
> there a way to automate this extraction across all the subjects?
>
> For example, how can I extract the average power over 300 - 500 msec for CZ
> electrode for each condition?
>
> Thanks
>
> -Muhammad
>
>
|