You should set the channel types of channels 20 and 50 to 'LFP' and that of the rest of the channels to 'Other'. Then specify 'LFP' as the spatial model and the names of the channels as source names. See the rat anaesthesia data example in the manual.

Best,

Vladimir

On Sun, Oct 11, 2015 at 9:00 PM, pari eghbali <[log in to unmask]> wrote:

Thank you for your help.
I have one more question! In 64 channels I want to find connectivity between channel 20 and channel 50. How can I define those areas in electromagnetic model of DCM? Should I define source location ( dimension of 64 channels) in Prep?
Thank you again for your prompt reply,
Best,
Arezoo

On Sun, Oct 11, 2015 at 6:58 AM, Vladimir Litvak <[log in to unmask]> wrote:
Dear Pari,

The channel data should be in the dat file. I think the example script has a data variable which you can replace with your own data.

Best,

Vladimir

On Sun, Oct 11, 2015 at 7:37 PM, pari eghbali <[log in to unmask]> wrote:
Hello
I am currently working with ECoG channel signals to investigate brain effective connectivity(DCM). I used a sample script of LFP to convert my data format to spm format. It gave me two format files:.dat and .mat. It seems both of them have header information since there was not any function in sample script to import my data. I am wondering to know where should I import the channel signals?

Thank you,
Pari