Unmixing Oscillatory Brain Activity by EEG Source Localization and Empirical Mode Decomposition
Table 1
Performance on synthetic data (average deviation between estimated and actual source components). Performances are averaged across the three SOI components and the 100 repetitions. The simulations containing distractors 1 and 2 are additionally averaged across the distractor frequency, while the simulations containing five distractors are averaged across SNR levels.
Deviation in phase (rad)
Deviation in frequency (Hz)
Temporal correlation
Distractor 1
1 sensor
0.175
0.205
0.955
4 sensors
0.559
0.901
0.752
1 + sensors
0.209
0.221
0.932
1 source
0.146
0.173
0.972
4 sources
0.156
0.177
0.967
1 + sources
0.154
0.177
0.968
Bandpass
0.164
0.178
0.920
EMD + SL
0.484
0.720
0.799
Distractor 2
1 sensor
0.208
0.276
0.939
4 sensors
0.218
0.231
0.932
1 + sensors
0.217
0.227
0.933
1 source
0.164
0.182
0.962
4 sources
0.193
0.198
0.947
1 + sources
0.173
0.182
0.957
Bandpass
0.211
0.204
0.900
EMD + SL
0.491
0.670
0.786
5 distractors
1 sensor
0.432
0.474
0.830
4 sensors
0.570
0.525
0.739
1 + sensors
0.439
0.404
0.816
1 source
0.390
0.433
0.850
4 sources
0.391
0.352
0.844
1 + sources
0.396
0.347
0.842
Bandpass
0.452
0.480
0.791
EMD + SL
0.509
0.804
0.776
Significant improvements () are indicated. Applying a paired t-test did not change the significance pattern. Each of the source-level decompositions is significantly better than the sensor-level decompositions and the EMD + SL.