[FieldTrip] Artifact in LCMV beamformer source localization

[Bushra Riaz Syeda]

Hello



I am using lcmv to source localize somatosensory response of Electric stimulation to the index finger of the left hand of subjects.



500 ms of post-stimulus interval is contrasted to 500 ms of pre-stimulus interval. The problem is I see strong activity in the middle of the head for couple of my subjects. It is very strong for one subject as shown ( link to figure 1: https://chalmersuniversity.box.com/s/jxmq5zp8k9m9tdfpogem7ee3r4z9q3ac )and week for other subjects ( link for figure 2: https://chalmersuniversity.box.com/s/o3yl57s6phr96f9rxh4wuthjcgllr2vv ) . I thought that noise bias towards the center of the head is usually taken care of when comparing conditions. Could somebody guide me how to solve this problem. Specially figure 1 where the noise bias is so strong that I don't see any activity in somatosensory cortex.



Thank you



Kind regards

Bushra Riaz

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