The Gate Theory of Pain Revisited: Modeling Different Pain Conditions with a Parsimonious Neurocomputational Model

Figure 2

Intrinsic plasticity is the property of real neurons that allows the neuron’s sigmoidal activation function to shift either leftwards or rightwards, so that the sigmoid is placed over intervals corresponding to the average net input of the neuron. (a) Initial position of the sigmoidal activation function. (b) If the values of net inputs of the neuron are low (as in case of inputs A, B, and C), the activation function shifts leftwards. (c) If net input values are high (as in D, E, and F), the sigmoid gradually shifts rightwards.