Integrate and Fire Neurons

• Trappenberg says that McCullouch and Pitts came up with the first neural model in 1943. That's not quite right as Lapicque came up with a similar model in 1907 (Abbott).
• None the less, it's pretty much the same idea as a Perceptron.
• For each input, multiply it by a weight, and add that weight to the total.
• If the total is over a threshold, the neuron fires.
• That is the neuron integrates activation from its presynaptic neurons, and fires if it gets enough.
• If the neuron fire, it in turns sends an output (weighted by the synapses) to all the neuron it connects to.
• In the perceptron model, time doesn't matter, because it is a one time system.
• In an IF system it does matter. The neuron can fire (or send a spike or just spike) in lots of time steps.