Allen P A, Smith A F, Vires-Collins H, Sperry S
Department of Psychology, Cleveland State University, Ohio 44115, USA.
Psychol Aging. 1998 Jun;13(2):218-29. doi: 10.1037//0882-7974.13.2.218.
The authors report 2 psychological refractory period (PRP) experiments in which the stimulus onset asynchrony (SOA) between Task 1 and Task 2 was 150 ms, 250 ms, 600 ms, and 1,100 ms for both younger and older adults. H. Pashler's (1994a) response-selection bottleneck theory predicts that SOA manipulations should not affect Task 1 performance, but that reaction time (RT) for Task 2 should increase as the SOA between the 2 tasks decreases (i.e., the classical PRP effect). In Experiment 1 (Task 1 = tone discrimination, Task 2 = dot location), older adults showed a larger PRP effect than younger adults did, although Task 1 RT was affected by SOA, suggesting that participants were grouping their responses on some trials. That is, participants were holding their response for Task 1 until they had completed processing Task 2, and then they responded to both tasks almost simultaneously. However, a subset of participants (11 younger adults and 11 older adults) who showed no evidence of response grouping on Task 1 continued to show a larger PRP effect for older adults on Task 2. In Experiment 2 (Task 1 = dot location, Task 2 = simultaneous letter matching), older adults continued to show a larger PRP effect than younger adults for Task 2, and Task 1 performance was unaffected by SOA. Consequently, these experiments provide evidence that older adults (relative to younger adults) exhibit a decrement in time-sharing at the response-selection stage of processing. These results suggest that attentional time-sharing needs to be added to the list of topics examined in aging research on varieties of attention.
作者报告了两项心理不应期（PRP）实验，其中，对于年轻人和老年人，任务1和任务2之间的刺激起始异步性（SOA）均为150毫秒、250毫秒、600毫秒和1100毫秒。H. 帕施勒（1994a）的反应选择瓶颈理论预测，SOA操作不应影响任务1的表现，但任务2的反应时间（RT）应随着两项任务之间的SOA减小而增加（即经典的PRP效应）。在实验1中（任务1 = 音调辨别，任务2 = 点定位），老年人比年轻人表现出更大的PRP效应，尽管任务1的RT受SOA影响，这表明参与者在某些试验中将他们的反应进行了分组。也就是说，参与者会在完成任务2的处理之前暂不做出任务1的反应，然后几乎同时对两项任务做出反应。然而，一部分在任务1上没有表现出反应分组迹象的参与者（11名年轻人和11名老年人）在任务2上，老年人仍然表现出更大的PRP效应。在实验2中（任务1 = 点定位，任务2 = 同时进行字母匹配），老年人在任务2上继续表现出比年轻人更大的PRP效应，并且任务1的表现不受SOA影响。因此，这些实验提供了证据，表明老年人（相对于年轻人）在加工的反应选择阶段表现出时间共享能力的下降。这些结果表明，注意力的时间共享需要被添加到关于各种注意力的衰老研究中所考察的主题列表中。
