The performance of the AWF was assessed by computer simulations, wherein encouraging results were obtained in imaging multiple focal sources from simulated fMRI and EEG data [24]. Fig. 6 shows the data obtained from a pilot experiment exploring the cortical pathway specialized in processing unilateral visual stimuli [24]. The experiment included two separate sessions with the identical visual stimuli for the EEG and fMRI data collection. The visual stimulation was a rectangular checkerboard within the lower left quadrant of the visual field; the checkerboard pattern was reversed at 2 Hz. With significantly enhanced spatial resolution, the AWF algorithm revealed a pathway sequentially activating V1/V2, V3/V3a, V5/V7 and intraparietal sulcus, in general agreement with the hierarchical organization of the visual system [142]. This pathway was also observed in the low-resolution images reconstructed from the VEP alone. In contrast, a fMRI-weighted source imaging algorithm [20, 21] showed a false positive source region in and around V1/V2 at the latency of 212 ms, whereas a more likely high-tier EEG source around V5, as observed from the EEG data, was missed. This experimental result indicates the promises in dynamic neuroimaging by integrating fMRI with EEG using the model-based adaptive Wiener filter.
