We investigated the mechanisms underlying timing of rapid interceptive actions under severe time constraints, such as those required in baseball, cricket, and tennis. To compensate for the temporal uncertainty of a moving target, participants were required to control their movement onset and/or duration. In Experiment 1, we tested how movement onset and/or duration are controlled under severe
... [Show full abstract] time constraints in a rapid baseball-simulation interceptive task. We found two distinct control strategies that modulated task performance. We also found that corrections to ongoing movements occurred more rapidly than had previously been reported. In Experiment 2, we used startling acoustic stimulation to investigate the detailed mechanisms underlying decisions about the timing of movement onset. Our findings indicate that the timing of movement onset is modified continuously via a subcortical motor circuit. Overall, our findings indicate that rapid movement decisions rely on a hybrid of feedforward and feedback control, allowing for the circumvention of severe time constraints during rapid interceptive actions.