A Computational Model of Action Specification in the Basal Ganglia

The basal ganglia has traditionally been modelled as a system that represents the available, discrete action space using a finite set of distinct and non-overlapping representational units. This limits these models from addressing questions around how the basal ganglia is involved in action specification: the selection of continuously valued action dynamics such as speed and vigor. In this article we present a novel computational model of the basal ganglia which incorporates vector-symbolic algebras in order to represent continuous action spaces. The stages of model development are presented along with simulation experiments to test the basic properties of the model. This work represents a promising foundational step in providing a mechanistic account for neuroscientific and behavioural evidence implicating the basal ganglia in action specification, thereby filling a gap in the literature.