Synapses

• Neurons are connected to each other by synapses.
• Chemical synapses are undirectional, and are relatively slow.
• They send over excitation or inhibition in 10s of milliseconds.
• Electrical synapses are faster and are often bidirectional.
• They function milliseconds.
• Most of the learning is done with synaptic change.
• With point models, this is done by changing the weight of the synapses.
• The standard rule is a Hebbian rule. Commonly this is spike timing dependent plasticity, and there are several variants of this rule.
• This is, of course, a simplification of the actual process.