The influence of voluntary actions on temporal preparation to visual stimuli

Humans and non-human animals can anticipate future events to optimize behavior. However, environments are shaped by both externally and voluntarily initiated events. This study examined how voluntary actions influence temporal preparation for visual stimuli. Across four experiments, we compared reaction times (RTs) using variable and constant foreperiod (FP) paradigms. In each experiment, the target stimuli were triggered by voluntary actions or externally, with FPs ranging from 0.6 to 2.8 seconds. Participants performed a go/no-go task (Experiment 1) or an orientation discrimination task (Experiments 2–4). We observed slower RTs for action-triggered stimuli than external stimuli, particularly at shorter FPs, with this effect diminishing as the FPs lengthened. This pattern was observed only in variable FP paradigms, indicating an interaction of voluntary actions and FP variability. In contrast, the constant FP paradigms did not show significant differences. These findings suggest that voluntary actions influence temporal preparation under temporal uncertainty. We discuss these results in light of current theories of temporal preparation, proposing new perspectives on the role of voluntary actions in shaping anticipatory behavior.