Source Activity Correlation Effects on LCMV Beamformers in a Realistic Measurement Environment

Table 1

Localization errors (LEs) in the LCMV outputs. Results are acceptable up until a 55% level of correlation. To our surprise, results for source #1 and source #3 (nearby sources) at 55% were slightly better than findings on the same couple of sources with 15% correlation as well as with far sources #1 and #2 simultaneously active at same correlation level (55%). Differences were always in the order of 1 voxel (5 mm). For high correlation between sources (95%), a more relevant error is detectable for nearby sources whereas only a single local maximum is retrievable in the area between the two sources for the far ones.

Correlation level	LE source #1- source #2 (mm)	LE source #1- source #3 (mm)
15%	S1, 5; S2, 5	S1, 5; S3, 10
55%	S1, 11; S2, 9	S1, 5; S3, 7
95%	S1, 15; S2, 12	Single peaks not detectable