Fig. 4.

Cortexwide activation changes. (A) Spatial distribution of change in mean activation comparing early to late trials for all targets for all subjects. Activations for individual electrodes are normalized against rest periods from the same electrode for a given run. Activation change values are blurred using a 12-cm FWHM Gaussian filter. Frontal areas and posterior parietal areas exhibited lessening in task-related activation over the course of BCI use. (B) Change in mean activation for all electrodes showing significant change from early to late trials, classified into approximate cortical areas.