Computational Mechanisms Mediating Inhibitory Control of Coordinated Eye-Hand Movements. Brain Sci. 2021. Jana, S. et al.

Inhibitory control refers to executive processes that stop contextually inappropriate actions and is a requirement for everyday life.  These processes have usually been studied using simple movements such as eye movements and button presses. However, majority of our daily activities involve complex multi-effector movements which are poorly understood. We have studied the computational mechanisms that generate one such complex two-effector system – coordinated eye-hand movements. Using behavioural tasks, accumulation-to-threshold, and race-to-threshold models we suggest that depending on the task context, coordinated eye-hand movements can operate in two modes – coupled and decoupled. The coupled mode operates when the task demands tight coupling between the effectors – the two effectors are initiated by a common motor command and stopped by a unitary inhibitory process. The decoupled mode operates when the task requires weaker coupling between the effectors- the two effectors are initiated by separate motor command and stopped by separate inhibitory processes.