This demo is written in JavaScript by Prof. Jaap Murre (use Google Chrome for best performance). You can set a temporary lesion by left-clicking on a cell (becomes black at first but recovers) and a permanent one with right-click (stays white; make temporary again by left-clicking). It is interesting to see how a converged map is able to repair a smallish lesion (black spot). A large lesion usually leads to a local reorganization of the map with the massive repair necessary. Use 'white lesions' to see what happens if you isolate areas of the map. It is also possible to turn off one of the color channels. E.g., turning of blue will lead to only red-green based colors to be presented. This is essentially a two-dimensional stimulus and the map should be able to reach an optimal layout, which is not possible with a three-dimensional color stream.