23-01-2012, 02:02 PM
Artificial Neural Networks
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Biological inspiration
Animals are able to react adaptively to changes in their external and internal environment, and they use their nervous system to perform these behaviours.
An appropriate model/simulation of the nervous system should be able to produce similar responses and behaviours in artificial systems.
The nervous system is build by relatively simple units, the neurons, so copying their behavior and functionality should be the solution.
Biological inspiration
The spikes travelling along the axon of the pre-synaptic neuron trigger the release of neurotransmitter substances at the synapse.
The neurotransmitters cause excitation or inhibition in the dendrite of the post-synaptic neuron.
The integration of the excitatory and inhibitory signals may produce spikes in the post-synaptic neuron.
The contribution of the signals depends on the strength of the synaptic connection.
Learning as optimisation
The objective of adapting the responses on the basis of the information received from the environment is to achieve a better state. E.g., the animal likes to eat many energy rich, juicy fruits that make its stomach full, and makes it feel happy.
In other words, the objective of learning in biological organisms is to optimise the amount of available resources, happiness, or in general to achieve a closer to optimal state.
