Video 4.
In vivo measurement from a phase-encoded mapping study of visual angle. (left) The stimulus is a counterclockwise rotating, counterphase flickering wedge. There are a total of 36 activations in the entire rotation series. In order to line up stimuli and activations, we used our measured 6-s neurovascular lag. Here, the stimulus is shown without flicker and at 10× actual presentation speed. (upper right) Activations from these stimuli reconstructed with the triangular sparse array. Note the poor localization (especially in the lower half of the field of view) and strange activation shapes. (lower right) Reconstructions using the high-density array. Activations are correctly placed with reasonable sizes. The videos have been thresholded such that changes in hemoglobin concentration below baseline are not shown (MPEG, 1 MB). .