C.R.A.B.: The Paradigm to Study Motor-Related Cortical Potentials in Children

In the current paper, we propose a novel paradigm to study motor-related cortical potentials: C.R.A.B. (Contrasting Routines Affecting Bereitschaftspotential). The paradigm is gamified in order to be easily transferred to the clinical children population in future studies. The typical "Libet-type" clock is replaced for this type of research by the gradual movement of the crab characters on the screen. Different modes of hide-and-seek game between the characters allowed to induce different decision-making scenarios during (and before) the movement initiation process. In particular, we used conditions with different availability of the external stimuli used as hints concerning the current position of the hiding crab, and a control condition with no hinting stimuli. As a result, we showed that readiness potential waveforms are decreased in the condition, where participants could choose the right movement immediately after trial onset based on visual hints in comparison to conditions with non-reliable hint and no-hint conditions. We suggest that our results favor the interpretation of the readiness potential as a counterpart of the contingent negative variation, reflecting rather an anticipation of a particular movement-related stimulus than the movement initiation (or movement-related intention) per se.