Oriet Chris, Brand John
Department of Psychology, University of Regina, Canada.
Vision Res. 2013 Mar 7;79:8-16. doi: 10.1016/j.visres.2012.12.004. Epub 2012 Dec 27.
Research suggests that subjects can compute the mean size of two sets of interspersed objects concurrently, but that doing so incurs a cost of dividing attention across the two sets. Alternatively, costs may arise from failing to exclude irrelevant items from the calculation of mean size. Here, we examined whether attention can be selectively deployed to prevent the inclusion of items from an irrelevant, concurrently displayed set in the computation of the relevant set's mean size. The results suggest that mean size is computed prior to the deployment of attention, failing to exclude processing of items that are irrelevant to the task. The influence of the irrelevant items is evident both with brief exposures of the set (200ms) and in a simultaneous judgment task with unlimited viewing time, suggesting that attention cannot be effectively deployed to facilitate selective averaging of the size of the relevant set. Size averaging appears to precede the deployment of selective attention, suggesting that it may be carried out automatically, without intention.
研究表明，受试者能够同时计算两组散布物体的平均大小，但这样做会产生将注意力分散到两组物体上的代价。或者，代价可能源于在计算平均大小时未能排除无关项目。在此，我们研究了注意力是否可以有选择地部署，以防止在计算相关集合的平均大小时纳入来自同时显示的无关集合的项目。结果表明，平均大小是在注意力部署之前计算的，未能排除与任务无关的项目的处理。无关项目的影响在集合短暂呈现（200毫秒）时以及在具有无限制观看时间的同时判断任务中都很明显，这表明注意力无法有效地部署以促进对相关集合大小的选择性平均。大小平均似乎先于选择性注意力的部署，这表明它可能是自动进行的，无需刻意为之。
