BENEFITS AND COST OF DUAL-TASKING IN A VIGILANCE TASK: A LABORATORY AND DRIVING SIMULATOR INVESTIGATION

Abstract

It is believed that under certain conditions, the presence of a secondary task such as a cell phone conversation would minimize a decrease in vigilance. The current study investigates this assumption by using two different vigilance paradigms. Further investigations were done by applying the same secondary task conditions to a monotonous driving scenario in a simulator. Results from the vigilance studies showed robust effects of dual task interference, and improvement in task performance for participants engaged in dual task from beginning to end. It was noted that the benefit of an improvement in task performance did not outweigh its cost as the reported improvement only reached a level similar to that of an individual who was low in vigilance. Results from the driving simulator indicated a possible driving improvement with the presence of a secondary task during later stages of the driving task as indicated by smaller lane keeping variability. The perceived improvement was questioned as there was a significantly poorer recall memory under dual task conditions. In general, it might be suggested that a secondary task may improve task performance under vigilance conditions, but the reported benefit may not outweigh its costs.