Attention failures versus misplaced diligence: Separating attention lapses from speed-accuracy trade-offs

► We examined the effects of altering speed-accuracy trade-offs through instructions in a sustained attention task (SART). ► We examined the effects of auditory alerts on sustained attention (using the SART). ► We argue that instructions emphasizing accuracy provide a more precise assessment of attention lapses. ► We found that auditory alerts have complex and sometimes deleterious effects on attention to task.