Perception-action integration is modulated by the catecholaminergic system depending on learning experience.

BACKGROUND The process underlying the integration of perception and action is a focal topic in neuroscientific research and cognitive frameworks such as the "Theory of Event Coding (TEC)" have been developed to explain the mechanisms of perception-action integration. The neurobiological underpinnings are poorly understood. While it has been suggested that the catecholaminergic system may play a role, there are opposing predictions regarding the effects of catecholamines on perception-action integration. METHODS Methylphenidate (MPH) is a compound commonly used to modulate the catecholaminergic system. In a double-blind, randomized crossover study design, we examined the effect of MPH (0.25mg/kg) on perception-action integration using an established "event file coding" paradigm in a group of N = 45 healthy young adults. RESULTS The data reveal that, compared to the placebo, MPH attenuates binding effects based on the established associations between stimuli and responses, provided participants are already familiar with the task. However, without prior task experience, MPH did not modulate performance, compared to the placebo. CONCLUSIONS Catecholamines and learning experience interactively modulate perception-action integration, especially when perception-action associations have to be reconfigured. The data suggest that there is a gain control based mechanism underlying the interactive effects of learning/task experience and catecholaminergic activity during perception-action integration.