[FieldTrip] Source Analysis Normalisation in-subject and in-group

[Roey Schurr]

Hi all,

We have a question regarding normalisation of EEG signals for source
reconstruction analysis.

We have EEG records (not ERP) of a few patients in two different conditions
(each condition consists of several 2 seconds segments/trials). Each
recording was done over a period of a few days, and in different sessions.
We also have anatomycal MRI scans for each patient (subject).

We would like to make two statistic comparisons:

1.    Compare the source analysis of the two conditions in each subject.

2.    Compare the source analysis of the two conditions, based upon all
subjects.

For the first comparison, we are puzzled about the appropriate way to
normalise and standardize our data, since each EEG segment was recorded at
a different time, and hence may be affected by different electrode
conductivity, for example. How would you normalise the data?

For the second comparison, of course, we would like to normalise the source
analysis results in the anatomycal level using ft_volumenormalise.

However, we are puzzled about the appropriate way to normalise and
standardize our data, since subjects differ from each other (for example,
anatomycally, resulting in changes of power spectrum).

How would you standartize the data between subjects?



Thank you very much,

best regards,

Aia and Roey
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