The countermanding saccade task has been used in many studies to investigate the neural mechanisms that underlie the decision to execute or restrain saccades. In this task, the presentation of a saccade target is sometimes followed by the appearance of a stop cue that indicates that the subject should cancel the planned movement. Performance has been modeled as a race between motor preparation and cancellation processes. In these studies, an important parameter is the time required to process the stop cue, referred to as the stop signal reaction time (SSRT). SSRT is estimated using statistical approaches, the validity of which has not been unequivocally established. A more direct measure of this parameter might be obtainable if a method were available to "unmask" the developing motor command. This can be accomplished by air-puff evoked blinks, which inhibit pontine omnipause neurons that serve as an inhibitory gate for the saccadic system. In the present study, puffs of air were used to elicit blinks at various times while monkeys performed a countermanding saccade task. If the developing motor command has not yet been cancelled, this should trigger a saccade. When blinks occurred between ~50-200 ms after target onset, saccades were often evoked. Saccades were rarely evoked more than ~70 ms after stop cue onset; this value was comparable to the SSRT estimates obtained using standard statistical approaches. When saccades occurred near the SSRT on blink trials, they were often hypometric. Overall, the study supports the validity of the statistical methods currently in use.