Ruthruff Eric, Pashler Harold E, Hazeltine Eliot
NASA Ames Research Center, Moffett Field, California 94035, USA.
Percept Psychophys. 2003 Jul;65(5):801-16. doi: 10.3758/bf03194816.
Most studies using the psychological refractory period (PRP) design suggest that dual-task performance is limited by a central bottleneck. Because subjects are usually told to emphasize Task 1, however, the bottleneck might reflect a strategic choice rather than a structural limitation. To evaluate the possibility that central operations can proceed in parallel, albeit with capacity limitations, we conducted two dual-task experiments with equal task emphasis. In both experiments, subjects tended to either group responses together or respond to one task well before the other. In addition, stimulus-response compatibility effects were roughly constant across stimulus onset asynchronies (SOAs). At the short SOA, compatibility effects also carried over onto response times for the other task. This pattern of results is difficult to reconcile with the possibility that subjects share capacity roughly equally between simultaneous central operations. However, this pattern is consistent with the existence of a structural central bottleneck.
大多数采用心理不应期（PRP）设计的研究表明，双重任务的表现受到一个中枢瓶颈的限制。然而，由于通常会告知受试者要重视任务1，所以这个瓶颈可能反映的是一种策略性选择，而非结构性限制。为了评估中枢操作尽管存在能力限制但仍可并行进行的可能性，我们进行了两项对任务同等重视的双重任务实验。在这两项实验中，受试者往往要么将反应归为一组，要么在另一任务之前很早就对其中一个任务做出反应。此外，刺激 - 反应相容性效应在不同的刺激呈现间隔（SOA）中大致保持不变。在短SOA时，相容性效应也会延续到另一任务的反应时间上。这种结果模式很难与受试者在同时进行的中枢操作之间大致平均分配能力的可能性相协调。然而，这种模式与存在结构性中枢瓶颈是一致的。
