Handling Negative wPLI² Debiased Values

Support & Discussions
1

Hi everyone,

I’ve been working with wPLI² debiased and, as expected (Vinck et al., 2011), I sometimes obtain negative values. From what I understand, these negative values don’t indicate “negative connectivity” per se, but rather reflect issues related to small sample sizes.

I wanted to ask how you typically handle these small negative values in statistical analyses or subsequent processing. Do you clip them to zero, use them as-is, or apply another approach?

Thanks,

2

Hi,

I haven’t worked with debaised wPLI before, but I did come across these old forum posts with a similar question and some suggestions: [FieldTrip] Negative values of debiased wPLI and [FieldTrip] Clarification on plotting WPLI.

Skimming through some papers using the measure, I didn’t see this mentioned in their methods sections. Maybe if you dig further you will find an example of handling this, or perhaps they just left the negative values as-is.

Sorry I can’t give a definitive answer. Maybe @wmvanvliet has experience with this measure?

3

Thanks for your reply. I have been reading papers that use this metric, but it is not clear what they do or even if they get negative values. That is why I posted here, in case someone knows. Thanks anyway, I will continue my search.

4

Sorry, I don’t :frowning:

1 Like