Fig. 2From: Perspective on photonic memristive neuromorphic computinga Diagram of the biological neuron highlighting the main components of the cell, the connection between axon and dendrite and the direction of signal propagation (red arrows). Reproduced with permission of© 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece. b Schematic illustration of McCulloch and Pitts model. The model consists of N inputs (IN) multiplied by corresponding N weights (wN), which are summed together (∑). The activation function (φ(∙)) evaluates the sum of the inputs and if a threshold is reached, the neuron will send its output signal. c Schematic illustration of an implementation of the leaky-integrate-and-fire (LIF) model. The four functional blocks are input, state, leak, and action potential. Combined in a circuit, they integrate linearly the input, exhibit a constant leakage, and emit a spiking signal when the potential crosses a threshold. In this way they implement an integrate-and-fire neuron. Reproduced from ref. [12] with permissionBack to article page