A computational model revealing the effect of dopamine on action selection

TL;DR

This paper presents a computational model of the cortex-basal ganglia-thalamus loop to study how dopamine influences action selection, particularly in the context of the Stroop task, by modeling dopamine's effect as a parameter in a nonlinear dynamical system.

Contribution

It introduces a novel nonlinear dynamical system model of the basal ganglia that incorporates dopamine effects to explain action selection mechanisms.

Findings

Dopamine modulates the balance between habitual and novel actions.

The model reproduces key features of the Stroop effect.

Dopamine's influence on action selection aligns with experimental observations.

Abstract

In order to reveal the effect of nigrostriatal dopamine system on action selection, first a computational model of the cortex-basal ganglia-thalamus loop is proposed and based on this model a simple compound model realizing the Stroop effect is established. Even though Stroop task is mostly used to examine selective attention, the main objective of this work is to investigate the effect of action selection on Stroop task. The computational model of the cortex-basal ganglia-thalamus loop is a non-linear dynamical system which is not only capable of revealing the action selection property of basal ganglia but also capable of modelling the effect of dopamine on action selection. While the interpretation of action selection is based on the solutions of the non-linear dynamical system, the effect of dopamine is modelled by a parameter of the model. The inhibiting effect of dopamine on the habitual behaviour which corresponds to word reading in Stroop task and letting the novel one occur corresponding to colour naming is investigated using the compound computational model established in this work.