, Volume 8, Issue 1, pp 73-80

Processing bottlenecks in dual-task performance: Structural limitation or strategic postponement?


Recent evidence indicates that a central bottleneck causes much of the slowing that occurs when two tasks are performed at the same time. This bottleneck might reflect a structural limitation inherent in the cognitive architecture. Alternatively, the bottleneck might reflect strategic (i.e., voluntary) postponement, induced by instructions to emphasize one task over the other. To distinguish structural limitations from strategic postponement, we examine a new paradigm in which subjects are told to place equal emphasis on both tasks and to emit both responses at about the same time. An experiment using this paradigm demonstrated patterns of interference that cannot easily be attributed to strategic postponement, preparation effects, or conflicts in response production. The data conform closely to the predictions of structural central bottleneck models.

During the course of this research, E.R. received support from National Research Service Award 1F31-MH10922 and from a National Research Council Postdoctoral Fellowship. The research was also supported by Grant 1-R29-MH45584 from the National Institute of Mental Health to H.E.P.