Interpreting amplitude envelope correlation (AEC) values

I am using amplitude envelope correlation (AEC) to estimate MEG connectivity. I need some help understanding the output of AEC, which is resulting in a value between -1 and 1. How should I interpret the negative values? Is it similar to the Pearson correlation? in the Pearson correlation, the closer the value is to 1 or –1, the stronger the linear correlation and a value of 0 denotes no linear correlation


This process "Amplitude Envelope Correlation" has been deprecated in June.
Please update Brainstorm and use the process "Envelope correlation" instead.
You won't have negative values with this one.

Hi @Francois,

I have a question, just out of curiosity. Why did you remove negative values? It is just from a "biological" point of view where negative coupligs do not make sense?

Thank you!

This is discussed also in these two topics:

@hossein27en @Sylvain @leahy @Raymundo.Cassani
Some text to explain the positive-only values should probably be added to the documentation for this method:

@hossein27en @Sylvain @leahy @Raymundo.Cassani @Marc.Lalancette Reminder

This implementation is aligned with those of MNE-Python's and Fieldtrip's. We will be looking into alternatives as soon as we have addressed other priorities in our development plan.