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Fig. 14.6. Self-organized LISSOM afferent and lateral weights. Compared with the SOM map in Figure 14.5, the afferent weights are less sharply tuned to individual digits and the clusters are more irregular and change more abruptly, resulting in more distributed responses (Figure 14.8). The black outline identifies the lateral inhibitory connection weights with above-average strength of the unit marked with the thick black square, which is part of the representation for digit 8. Inhibition goes to areas of similar functionality (i.e. areas sensitive to similar input), thereby decorrelating the map activity and forming a sparse representation of the input.