Fixation offset and stop signal intensity effects on saccadic countermanding: a crossmodal investigation.

Two experiments utilized the stop signal paradigm to examine whether fixation offset and stop signal intensity influenced saccadic inhibition. There was a robust fixation offset effect on saccadic latencies. However, contrary to expectations, fixation offset did not influence saccadic inhibition latencies. Importantly, saccadic inhibition latencies were found to be influenced by stop signal salience, with a more intense signal leading to faster stopping. This pattern of results was observed whether the stop signal was presented in the visual or auditory modality. The results provide new insights into the mechanisms of inhibition and help resolve previous inconsistencies in the literature.