Mayr Ulrich
Department of Psychology, University of Oregon, Eugene 97403, USA.
Psychon Bull Rev. 2006 Oct;13(5):794-9. doi: 10.3758/bf03193999.
Schneider and Logan (2006) recently showed that cue-switch and task-switch costs are sensitive to the relative probability of cue switches versus task switches. From this they concluded that task-switch costs reflect priming of cue-cue transitions rather than actual task-switching operations. However, because this design confounded probability of specific cue transitions with probability of task switches, the results could also reflect task-switch-level adjustments. The present experiment (N = 80) pits the critical prediction of the cue-priming account, namely that costs for high-probability cue-cue transitions are smaller than for low-probability cue-cue transitions, against the main prediction of the switch-probability account, namely that switch probability, irrespective of specific cue-cue transitions, determines switch costs. Whereas the cue-priming prediction was rejected, a specific version of the probability account--that subjects are sensitive to the probability of a task switch, given a cue switch--was fully confirmed. Thus, tasks are in fact the critical representational units that determine task-switch cost.
施奈德和洛根（2006年）最近表明，线索转换和任务转换成本对线索转换与任务转换的相对概率敏感。据此他们得出结论，任务转换成本反映的是线索 - 线索转换的启动，而非实际的任务转换操作。然而，由于该设计将特定线索转换的概率与任务转换的概率混淆了，结果也可能反映了任务转换层面的调整。本实验（N = 80）将线索启动理论的关键预测，即高概率线索 - 线索转换的成本低于低概率线索 - 线索转换的成本，与转换概率理论的主要预测，即转换概率（与特定线索 - 线索转换无关）决定转换成本，进行了对比。虽然线索启动预测被否定，但概率理论的一个特定版本——即给定线索转换时，受试者对任务转换的概率敏感——得到了充分证实。因此，任务实际上是决定任务转换成本的关键表征单元。
