Mechanisms of dual-task interference

Doing two tasks at once often leads to worse performance than doing just one task. The present article deals with the mechanisms of dual-task interference when performing quite elementary cognitive tasks (e.g., pressing a button in response to a tone). These mechanisms are typically investigated using the “psychological refractory period” (PRP) paradigm. Traditional accounts of dual-task interference assume a central information-processing bottleneck at the level of decision and response selection. New empirical evidence suggests, however, that interference also comes from other processes, such as the encoding and retrieval of information in short-term memory as well as the cognitive control of task order. This diversity of mechanisms of dual-task interference requires a substantial extension of traditional theoretical frameworks. This extension also casts new light on applied issues of dual-task interference, such as using cell phones while driving