A neurally plausible schema-theoretic approach to modelling cognitive dysfunction and neurophysiological markers in Parkinson's disease

The cognitive mechanisms underlying sequential action selection in routine or everyday activities may be understood in terms of competition within a hierarchically organised network of action schemas. We present a neurobiologically plausible elaboration of an existing schema-based cognitive model of action selection in which the basal ganglia implements an activation-based selection process that mediates between assumed cortical representations of rule-based schemas. More specifically, the model employs a network of basal ganglia units with computations performed by individual BG nuclei, embedded in a corticothalamic loop that disinhibits schemas according to the received feedback. We provide bridging assumptions for linking the operation of the model with ERP components that describe the error-related negativity (ERN) and the parietal switch positivity (PSP), and evaluate the model against behavioural and neural markers of performance of the Wisconsin Card Sorting Test by healthy control participants and Parkinson's Disease patients.