Dougherty Michael R P, Hunter Jennifer
Department of Psychology, University of Maryland, College Park, Maryland 20782, USA.
Mem Cognit. 2003 Sep;31(6):968-82. doi: 10.3758/bf03196449.
In this research, we examined the role that individual differences in working memory (WM) capacity, the strength of alternatives, and time constraints play in probability judgment and subadditivity. With a laboratory-based learning task, Experiment 1 revealed that the degree to which participants' probability judgments were subadditive was negatively correlated with a measure of WM capacity, even when variance due to short-term memory capacity was removed. In addition, participants were more subadditive when the viable alternatives were all rather weak. Experiment 2 extended the WM-capacity-subadditivity correlation to a population judgment task and revealed that subadditivity increases when the judgment task is performed under time constraints. Results support a model that assumes that people make probability judgments by comparing the focal hypothesis with relevant alternatives retrieved from long-term memory and that people high in WM span include more alternatives in the comparison process. Time constraints are assumed to truncate the alternative generation process, leading to fewer alternatives being recalled from long-term memory.
在本研究中，我们考察了工作记忆（WM）容量的个体差异、备择项的强度以及时间限制在概率判断和次可加性中所起的作用。通过一项基于实验室的学习任务，实验1表明，即使去除了短期记忆容量导致的方差，参与者概率判断的次可加程度仍与WM容量的一种测量指标呈负相关。此外，当可行的备择项都相当弱时，参与者的次可加性更强。实验2将WM容量与次可加性的相关性扩展到群体判断任务，并表明当判断任务在时间限制下进行时，次可加性会增加。结果支持了一个模型，该模型假设人们通过将焦点假设与从长期记忆中检索到的相关备择项进行比较来做出概率判断，并且WM跨度大的人在比较过程中会纳入更多的备择项。时间限制被认为会截断备择项生成过程，导致从长期记忆中回忆起的备择项减少。
