2.3.2 The Perceptron

In late 1950s, Frank Rosenblatt introduced a network composed of the units that were enhanced version of McCulloch-Pitts Threshold Logic Unit (TLU) model. Rosenblatt's model of neuron, a perceptron, was the result of merger between two concepts from the 1940s, McCulloch-Pitts model of an artificial neuron and Hebbian learning rule of adjusting weights [BL96]. In addition to the variable weight values, the perceptron model added an extra input that represents bias. Thus, the modified equation from (2.1) is now as follows:

$$Sum = \mathop{\sum_{i = 1}^{N}}{I_{i} W_{i}} + b,$$ (2.3)

where $b$ represents the bias value.