Pattern association is the technique of memorizing input-output patterns in a heteroassociative network architecture, or input patterns only in anautoassociative network, so as to recall the patterns when a whole new input pattern is presented. It is certainly not required that the new input pattern be exactly the same as one which is memorized. It may be different, but similar to it. Three exemplar patterns are demonstrated in figure 4.27. After memorizing them in a system, a new pattern is presented, a corrupted variant of the pattern 3. An associative memory system should associate this pattern with one among the memorized patterns. This can be a task for an autoassociative network architecture.