Not all summary statistics are made equal: Evidence from extracting summaries across time
Not all summary statistics are made equal: Evidence from extracting summaries across time
复制标题
DOI：
10.1167/15.4.5
复制
发表时间：
2015-04-01
影响因子：
1.8
通讯作者：
Boynton, Geoffrey M.
中科院分区：
文献类型：
--
作者：
Hubert-Wallander, Bjorn;Boynton, Geoffrey M.
在过去的15年中，许多行为学研究表明，人类视觉系统可以沿着各种特征维度提取一组物品的平均值，通常非常方便和准确。这些项目集的有效表示通常被称为摘要表示，但是对于它们的计算是否构成一个单一的过程，或者是否涉及不同领域的不同机制，我们知之甚少。在这里，我们要求参与者报告在四个不同的特征维度上随时间连续呈现的一组项目的平均值。然后，我们测量了信息流的不同部分对报告摘要的贡献。我们发现，这种时间加权分布在不同的域之间差异很大。具体来说，对平均物体定位的总结（实验1）受到早期项目的影响大约是后期项目的2.5倍。然而，平均物体尺寸（实验1）、平均面部表情（实验2）和平均运动方向（实验3）的摘要受后期项目的影响更大。这些因因效应和近因效应表明，计算时间的汇总表示并不平等地包含所有项目。此外，我们的研究结果支持这样的假设，即摘要表示在不同的特征域中运行不同，并且可能由不同的机制提供。
Over the past 15 years, a number of behavioral studies have shown that the human visual system can extract the average value of a set of items along a variety of feature dimensions, often with great facility and accuracy. These efficient representations of sets of items are commonly referred to as summary representations, but very little is known about whether their computation constitutes a single unitary process or if it involves different mechanisms in different domains. Here, we asked participants to report the average value of a set of items presented serially over time in four different feature dimensions. We then measured the contribution of different parts of the information stream to the reported summaries. We found that this temporal weighting profile differs greatly across domains. Specifically, summaries of mean object location (Experiment 1) were influenced approximately 2.5 times more by earlier items than by later items. Summaries of mean object size (Experiment 1), mean facial expression (Experiment 2), and mean motion direction (Experiment 3), however, were more influenced by later items. These primacy and recency effects show that summary representations computed across time do not incorporate all items equally. Furthermore, our results support the hypothesis that summary representations operate differently in different feature domains, and may be subserved by distinct mechanisms.