Intra-session evaluation of the classification performance versus the number of EEG electrodes for different sensor selection approaches.

<p>The horizontal line <i>All</i> is a reference showing the performance using all available 62 electrodes. The grey patches correspond to histograms of performances of 100 randomly sampled electrode constellations. The elongation in <i>y</i>-direction spans the range of the occurring performances and the width of the patches in <i>x</i>-direction corresponds to the quantity of results in that particular range. The three black stars represent widely accepted sensor placements for 19, 32, and 62 EEG electrodes. All other curves depict the mean classification performance over all subjects and cross validation splits. The results for - sensors are shown separately in the inset. By using an inset the curves in the main graphic appear less compressed.