In Adrian’s frog muscle experiments, a neuron might fire one hundred spikes in response to a certain weight. But after this first exposure, the neuron quickly adapts; if you apply the same weight shortly after, it might elicit only eighty spikes. And as you keep doing this, the number of spikes continues to decline. This applies in many neurons throughout the brains of animals—the stronger the stimuli, the greater the change in the neural threshold for spiking.
