He notes that the output of neurons is digital: an axon either fires or it doesn’t. This was far from obvious at the time, in that the output could h… - John von Neumann

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He notes that the output of neurons is digital: an axon either fires or it doesn’t. This was far from obvious at the time, in that the output could have been an analog signal. The processing in the dendrites leading into a neuron and in the soma neuron cell body, however, are analog. He describes these calculations as a weighted sum of inputs with a threshold.