Biological neurons

The working principles of ANNs are inspired by how a human brain works, depicted in Figure 7. The receptors receive the stimuli either internally or from the external world; then they pass the information into the biological neurons for further processing. There are a number of dendrites, in addition to another long extension called the axon.

Towards its extremity, there are minuscule structures called synaptic terminals, used to connect one neuron to the dendrites of other neurons. Biological neurons receive short electrical impulses called signals from other neurons, and in response, they trigger their own signals:

Working principle of biological neurons

We can thus summarize that the neuron comprises a cell body (also known as the soma), one or more dendrites for receiving signals from other neurons, and an axon for carrying out the signals generated by the neurons.

A neuron is in an active state when it is sending signals to other neurons. However, when it is receiving signals from other neurons, it is in an inactive state. In an idle state, a neuron accumulates all the signals received before reaching a certain activation threshold. This whole thing motivated researchers to introduce an ANN.