One of the new features in BESA 5.1 are 3D imaging tools. The Multiple-Source Beamformer (MSBF) provides a method to image evoked and induced activity in the time-frequency domain.
The figure shows an MSBF image of low-frequency (4-12 Hz) evoked brain responses to visual flowfield stimulation. The beamformer computes changes of power in the time-range from 50-300 ms poststimulus relative to the prestimulus baseline. The MSBF image is superimposed to the subject's anatomical MRI. The image reveals involvement of primary visual areas in the occipital cortex and of the right-hemispheric MT area.
Superimposed is an equivalent current dipole model that was fitted to the averaged evoked response.