In this letter, a novel critic-like algorithm was developed to extend the synaptic plasticity rule described in Florian (2007) and Izhikevich (2007) in order to solve the problem of learning multiple distal rewards simultaneously. The system is augmented with short-term plasticity (STP) to stabilize the learning dynamics, thereby increasing the system's learning capacity. A theoretical threshold is estimated for the number of distal rewards that this system can learn. The validity of the novel algorithm was verified by computer simulations.
© 2012 Massachusetts Institute of Technology