- In 1975, Kunihiko Fukushima introduced the Cognitron network, which was an extension of the original perceptron and was able to handle pattern recognition problems better than the perceptron. - The Cognitron used multiple layers of convergent subcircuits that allowed it to discriminate between patterns to some degree, unlike the perceptron. - Fukushima later modified the Cognitron into the Neocognitron in 1980 by adding additional summation nodes, which made the network able to recognize patterns regardless of their position in the visual field.