Motor overload: GABAergic index of parallel buffer costs

Everyday life actions are continuously adjusted to the context and halted promptly when the environment requires to switch from the current action to a different one. Action changing/adaptation is a multicomponent process that effectively optimizes the chaining of different sub-actions. This process is based on different control strategies that operate on a continuum, adopting either serial (i.e., a task goal is activated after the previous one has been carried out) to parallel (i.e., multiple goals active at the same time or overlay mode) strategies [[1]]. In the parallel strategy, the different task sub-goals share the same limited processing capacity, ultimately hampering response speed. Otherwise, the serial strategy produces no interference between sub-goals. One early component of the action changing process is the preliminary stop of the ongoing action. This stopping has been related to the activity of inhibitory GABAergic circuits in the motor system, that may account for individual differences in action stopping performance [[2],[3]]. However, to date, it is unclear if and how GABAergic neurotransmission relates to individual strategies adopted in action changing.