Nadja Jankovic¹, Rachel Yapp¹, Aaron Richardson¹, Vincent Di Lollo¹, Thomas M. Spalek¹; ¹Simon Fraser University

When a task-irrelevant cue (e.g., a tone) becomes familiar, ignoring it is easy. If it changes suddenly (e.g., increases pitch), it can cause distraction and slowed responses. This effect – called deviance distraction – is observed during visual tasks that are preceded by tones of either a standard pitch (e.g., 80% of trials) or a deviant pitch (20%). Yet similar conditions elicit the alerting effect: leading alerting cues quicken responses during visual tasks. Trials with alerting cues (on 50% of trials or more) are compared to no-cue trials. These two contradictory effects have been explained by invoking the same neural mechanisms: salient cues cause a brief increase in arousal by triggering locus coeruleus activity, which fires strongly to salient, novel, or task-relevant stimuli. Notably, distraction and alerting are rarely considered in tandem, and accounts reconciling both effects remain to be proposed. One possible source of the conflict is the different probabilities of cue occurrence: because deviant cues occur infrequently (20%) compared to alerting cues (50% or more), simply reducing the number of alerted trials may change the alerting effect to distraction. In Experiment 1, participants performed a pop-out search task that was either preceded by a visual cue (white flash, 20% of trials) or a blank interval (80%). We found no differences between cue conditions, but the cue reduced the response repetition effect, which has been reported in distraction studies. Experiment 2 had identical procedures except for the inclusion of a standard cue (black flash, 80% of trials). Surprisingly, there were no differences between cue conditions, and no response repetition interaction. Interestingly, responses were significantly faster in E2 than in E1, indicating an overall alerting effect when a cue occurred every trial. The implications are discussed in the context of both deviant distraction and alerting.

Acknowledgements: Natural Sciences and Engineering Research Council of Canada