[Eeglablist] Connectivity normalization

[Michael Glassen - Biomedical Engineer]

Hi Makato,

I had a follow up, I’m doing a similar normalization to task related connectivity, and I was wondering if it’s good practice to also apply some filtering(moving average) to the connectivity data either before or after normalizing to help smooth out the effects in the time domain as I noticed they can oscillate.

Best,

Michael Glassen



> On Jun 14, 2023, at 10:54 PM, Makoto Miyakoshi via eeglablist <eeglablist at sccn.ucsd.edu> wrote:
>
> Hello Sampath,
>
> You may divide the post values with the pre values. I have been using
> subtraction to show the differences between the conditions in the past. I
> guess both should work just fine. Or do you see any concern in using
> division there?
>
> Makoto
>
>> On Wed, Jun 14, 2023 at 8:23 AM Sampath Thoutanahalli Kapanaiah <
>> sampath.kapanaiah at uni-ulm.de> wrote:
>>
>> Dear Makoto,  Arnaud Delorme and EEGLab Users,
>>
>> I hope this email finds you well. I seek guidance on the appropriate
>> method for normalizing SIFT resting state connectivity matrix data obtained
>> from LFP continuous recordings in mice depth electrodes.
>>
>> My dataset consists of connectivity matrices calculated over 20-second
>> intervals spanning a total duration of 60 minutes. The first 10 minutes of
>> the recording represent the pre-injection baseline, while the remaining
>> time captures the post-injection data.
>>
>> To check the drug's effect, I am interested in normalizing the
>> post-injection connectivity data relative to the baseline. I have been
>> dividing the post-injection connectivity values by the connectivity values
>> obtained during the 10-minute baseline period. However, I am uncertain if
>> this approach is the most appropriate and would greatly appreciate your
>> expert advice.
>>
>> Considering the nature of the data and the desired normalization, could
>> you kindly suggest the best method to normalize the connectivity matrix
>> data to the baseline? I want to ensure that differences do not solely
>> influence any observed changes in connectivity post-injection in the
>> baseline values.
>>
>> Thank you very much for your time. I look forward to your valuable
>> insights and suggestions.
>>
>> Best regards,
>> Sampath
>>
>> PhD student,
>> Ulm University
>> Ulm, Germany
>>
>>
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