Detecting transient changes in dynamic displays: the more you look, the less you see.

OBJECTIVE: Two experiments examined the detectability of transient changes in cluttered and dynamic displays and optimal scan strategies for performance.
BACKGROUND: Research has demonstrated that onset changes are prioritized by the attention system and onsets are often used to signal important display changes. However, research has mostly used uncluttered, static displays and has largely ignored the role of scan strategy.
METHOD: We had participants monitor a cluttered and dynamic display and respond when an object changed color or onset abruptly. Scan strategies were also evaluated. In another experiment participants were instructed to use particular strategies to detect changes.
RESULTS: Consistent with previous results, onset events were detected better than were color change events. Scan strategy accounted for a large proportion of variance in detection performance. Participants who made few eye movements performed best. Participants who actively scanned the display performed worst. When poor performers were instructed to make few eye movements, their performance matched that of the best performers.
CONCLUSION: Onset alerts can be an effective means of signaling important events in complex displays. Additionally, scan strategy plays an important role in the detection of transient events. APPLICATION: These results have important implications for training operators to search for transient changes within dynamic and cluttered displays.