Artificial neuron

From Citizendium
Revision as of 05:41, 29 April 2007 by imported>Derek Harkness (Add workgroup tag and cz live)
Jump to navigation Jump to search

Artificial neurons (also called McCulloch-Pitts neurons) are simple processing units based on the biological neurons. They can get connected to form artificial neural networks.

Artificialneuron.png

Behavior

Input signals are multiplied by values called weights producing a new value called activation. After the activation is produced, it gets filtered if the input doesn't exceed a value called threshold.

Transfer Functions

Transfer functions is the name given for the functions which apply the threshold to the activation value. This functions can be discrete or continuous, and they also can be defined as step functions.

Analogy to Biological Neurons

In biological neurons there is a similar behavior. Inputs are electrical pulses transmitted to the synapses (terminals in the dendrites). Electrical pulses produce a release of neurotransmitters which may alter the dendritic membrane potential (Post Synaptic Potential). The Post Synaptic Potential travels over the axon, reaching another neuron, which will sum all the Post Synaptic Potentials received, and fire an output if the total sum of the Post Synaptic Potentials in the axon hillock received exceeds a threshold.