[FieldTrip] Source analysis and sensor space differences

[John Nguyen]

Hi All,

My Name is John Nguyen and I am working at the Reinhart Cognitive
Neuroscience Lab at Boston University. I have been using Fieldtrip (Version
4/10/17)​​ for several months now and have decided to tackle
SourceAnalysis. After a few weeks of struggling with it, I find myself
still far from the goal post.

A milestone I'm trying to achieve is plotting activity in the visual cortex
due to a visual stimulus onset. This activity is easily reflected in my
sensor-level plots but, in the source-level, it's projection is more than a
bit wonky [image link, Negative sensor potential ,1.09-1.23s, following
visual stimulus followed by positive sensor potential at 1.22-1.48s neither
of which are present in source space.]
[https://drive.google.com/file/d/0B2UdTHvTeS9NNWV6dGJKZ2JWbk0/
view?usp=sharing]

In my current code I am using Fieldtrip templates to minimize error on my
end as much as possible.
"elec = ft_read_sens('standard_1020.elc');
load('standard_bem.mat','vol')
load('standard_sourcemodel3d8mm.mat','sourcemodel')
mri = ft_read_mri('single_subj_T1_1mm.nii');"

My Sourceanalysis is timelocked LCMV with a relative baseline change at
times -0.2 to 0.0s. I also preformed a relative baseline change on my
sensor-level data because I was wondering if the disparity was a baseline
issue. I've reached a dead-end and would appreciate any help. I've attached
links to my script
[https://drive.google.com/file/d/0B2UdTHvTeS9NT05uWUk4T0hDUjQ/
view?usp=sharing]

and data (no rereference, no artifact reject)
[https://drive.google.com/file/d/0B2UdTHvTeS9NSl8yaW9fcXZWSjQ/
view?usp=sharing]

and sensor cap layout.
[https://drive.google.com/file/d/0B2UdTHvTeS9NSGJXZUszOHBUbGM/
view?usp=sharing]


Best regards,
John Nguyen
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20170919/304243b9/attachment-0001.html>