Neural signatures of voluntary action with long-range intentions

Abstract

Long-range intentions are a vital feature of real-world voluntary action, but have not been extensively studied in relation to their neural correlates. The current study adopted a procedure instead that previous highly repeatable and single decision point paradigms, in which voluntary action (generated by a random ratio (RR), yoked random interval (RI) reinforcement schedule) could be compared with a yoked condition in which participants responded to an external cue. Participants were required to reach the highest reward rates they could in the RI schedule, which offered an indicator of the extent to which long-range intentions have been formed. A classical RP amplitude occurred preceding participants’ keypress action in the current study. EEG amplitudes and EEG variability decreased significantly prior to voluntary action, compared to externally triggered action. These results extend previous findings regarding voluntary action arising from a particular set of long-range intention-based processes, rather than the outcome of stochastic neural fluctuations. Notably, EEG amplitudes decreased significantly differently prior to higher RI-reward rates (i.e., higher plane of long-range intentions formed). The novel experimental paradigm suggests a possible contribution of long-range intentions on the neural activities stage prior to voluntary action.