Attentional limitations in doing two tasks at once: The search for exceptions

ABSTRACT—People generally have difficulty doing two tasks at once. To explain this fact, theorists have proposed that central processing—the thought-like stages following perceptual encoding and preceding response processing— takes place for only one task at a time. Because this bot-tleneck imposes severe limits on human cognitive process-es, research has attempted to find exceptions. There is now solid evidence that, at least in the laboratory, the entire bo-ttleneck can be completely bypassed under favorable com-binations of circumstances. While these findings provide a ray of hope for enabling parallel multitasking in real-world scenarios, it will not be easy to take advantage of the combination of conditions that appear to be necessary. KEYWORDS—dual-task interference; central bottleneck The question of whether humans can perform multiple tasks i