Figure 6:

Increasing the number of synaptic states decreases performance. (A) The deviation from the matching law increases as the number of synaptic states m increases and it causes a decrease of the harvesting performance. (B) As m increases, the difference I_L — I_R between the total synaptic currents injected in the choice populations decreases. (C, D) This decrease is due to fact that the equilibrium distribution of the two synaptic populations is biased toward the same side. The synaptic current difference is due to the skewness of the distribution. As m increases, the equilibrium distribution becomes progressively more localized around one of the two synaptic bounds, making the difference between I_L and I_R progressively smaller. This leads to an increased deviation from the matching law (A), which deteriorates the performance.