[FieldTrip] lcmv weightnorm

[Schoffelen, J.M. (Jan Mathijs)]

Hi Edoardo,

The first thing I would check would be the sanity of the sensor level data. Are the sensor level data (i.e. the time series on which you computed the sensor covariance, and te resulting sensor covariance) real-valued? If this is not the case, then somehow the spatial filters that you compute automagically become complex-valued. If it’s not due to the sensor level data being ill-behaved in terms of complex-valuedness, my next diagnostic step would be to put some breakpoints in the matlab code (ft_inverse_lcmv), and investigate step by step what is happening.

Good luck,
Jan-Mathijs

> On 27 Sep 2024, at 18:50, Edoardo Pinzuti via fieldtrip <fieldtrip at science.ru.nl> wrote:
>
> Dear Fieldtrip users,
>
> Do you know why if I use this setting cfg.lcmv.weightnorm = 'nai' for my lcmv beamformer analysis I get complex value avg.mom.
>
> I am doing a lcmv on resting state data and I need the timecourses of specific ROIs is this "nai" parameter required ?
>
> Thanks
> Edoardo
> _______________________________________________
> fieldtrip mailing list
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmailman.science.ru.nl%2Fmailman%2Flistinfo%2Ffieldtrip&data=05%7C02%7Cfieldtrip%40science.ru.nl%7C4c84195fb39d4d1ff7ab08dce2dacf7e%7C084578d9400d4a5aa7c7e76ca47af400%7C1%7C0%7C638634676624524382%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=ProB%2BDd8z2rcnhu3gaMF1DcQEGm4JQwhLvYKftcgM7k%3D&reserved=0
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1371%2Fjournal.pcbi.1002202&data=05%7C02%7Cfieldtrip%40science.ru.nl%7C4c84195fb39d4d1ff7ab08dce2dacf7e%7C084578d9400d4a5aa7c7e76ca47af400%7C1%7C0%7C638634676624680605%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=AcqIJq5rsm0Xf4Jd%2BEy0skeMoINCQteA%2BPTVSXvCQVQ%3D&reserved=0