Brief wakeful resting can eliminate directed forgetting

When cued to intentionally forget previously encoded memories, participants typically show reduced recall of the memories on a later recall test. We examined how such directed forgetting is affected by a brief period of wakeful resting between encoding and test. Encoding was followed by a “passive” wakeful resting period in which subjects heard emotionally neutral music or perceived neutral pictures, or it was followed by an “active” distraction period in which subjects were engaged in counting or calculation tasks. Whereas typical directed forgetting was present after active distraction, the forgetting was absent after wakeful resting. The findings indicate that the degree to which people can intentionally forget memories is influenced by the cognitive activity that people engage in shortly after learning takes place. The results provide first evidence on the interplay between wakeful resting and intentional forgetting.     

Semantic coherence and fallacies in estimating joint probabilities

In three experiments on joint probability estimation, gist representations were manipulated with analogies, and the suboptimal strategy of ignoring relevant denominators was counteracted with training in using 2 × 2 tables to clarify joint probability estimates. The estimated probabilities of two events, as well as their conjunctive and disjunctive probabilities, were assessed against two benchmarks, logical fallacies and semantic coherence—a constellation of estimates consistent with the relationship among sets. Fuzzy‐trace theory (FTT) predicts that analogies will increase semantic coherence, and a table intervention affecting denominator neglect will both increase semantic coherence and reduce fallacies. In all three experiments, analogies increased semantic coherence. In both experiments training participants to use 2 × 2 tables, such tables reduced fallacies and increased semantic coherence. As the relations among sets in the problem materials progressed in cognitive complexity from identical sets, mutually exclusive sets, and subsets to overlapping sets, fallacies generally increased, and semantic coherence generally decreased. These findings indicate that denominator neglect is pervasive, but that it can be remedied with a straightforward intervention that clarifies relations among sets. Further, intuitive gist‐based probability estimation can be improved through the use of simple analogies. Copyright © 2009 John Wiley & Sons, Ltd.     

1918年流感世界大流行病毒株溯源

发生于1918年的第一次世界流感大流行夺走至少两千万人的生命,这场灾难赋予了科学家探求其来源的巨大责任感.病毒学家发挥了严谨而又富有创造性的科研精神,使流感病毒的真实面目得以逐步揭开.这些研究成果加深了我们对流感病毒本身的认识,更为重要的是,为下一次流感世界大流行的防治提供了若干有价值的信息.     

文本阅读中信息精确化推理的初步研究

采用动窗技术对文本阅读中信息精确化推理进行了初步研究。实验1研究在工作记忆范围内,信息精确化推理是即时发生的还是当局部信息不连贯时再重新追溯才发生。实验2探究信息精确化推理在长时记忆中是否也会发生。结果表明,文本阅读中的信息精确化推理,不管需要进行精确化推理的句子与包含推理所需信息的句子是处于同一工作记忆范围内,还是处于长时记忆中,推理都是即时发生的。     

Eight-year-olds,but not six-year-olds,perform just as well as adults when playing Concentration: Resolving the enigma?

Anecdotal reports suggest that children often outperform adults when playing Concentration. This is surprising as cognitive processes tend to develop progressively throughout childhood. To date, very few studies have examined this apparent paradox, and with mixed results. In the present study, the ability of 6-year-olds (n = 34), 8-year-olds (n = 48), and adults (n = 38) to play Concentration was examined in a controlled computer-based setup involving eye tracking. The main dependent variables were the number of moves and time in seconds to finish the first nine (out of 12) matching pairs. The results revealed that while 6-year-olds were outperformed by older children and adults, 8-year-olds performed just as well as adults. It is suggested that Concentration may represent a cognitive challenge rarely encountered in the real world, and when playing Concentration, adults seem to use strategies that are effective in real life situations, but may be less appropriate when playing the game.     

Reactivation and Consolidation of Memory During Sleep

ABSTRACT— Recent research has shown compellingly that sleep supports the consolidation of declarative memories for events and facts. During consolidation, memories are stabilized against future interference and undergo qualitative changes with regard to their "explicitness" and underlying neural representation. In this article, we argue that declarative memory consolidation during sleep is based on covert reactivations of newly encoded memory traces in the hippocampus. During slow-wave sleep (SWS), the prominent slow oscillations act to synchronize the repeated reactivation of the newly encoded representations in hippocampal networks with the generation of spindle activity in the thalamus, supporting changes in neocortical networks that contribute to long-term memory storage. In this view, sleep plays an active role in the consolidation of memories, in which the neuronal reactivation of newly acquired memories is critical for the redistribution and integration of these memories into the network of pre-existing long-term memories.     

Between Mind and Trace — A Research into the Theories on Xin 心 (Mind) of Early Song Confucianism and Buddhism

From Han Yu’s yuan Dao 原道 (retracing the Dao) to Ouyang Xiu’s lun ben 论本 (discussing the root), the conflicts arising from Confucianists’ rejection of Buddhism were focused on one point, namely, the examination of zhongxin suo shou 中心所守 (something kept in mind). The attitude towards the distinction between mind and trace, and the proper approach to erase the gap between emptiness and being, as well as that between the expedient and the true, became the major concerns unavoidable for various thinkers to integrate the two teachings and to propel academic development. “To understand by mind” and “to blame for matter” were of crucial methodological significance for transcendence in both Confucianism and Buddhism. The arguments of Confucian scholars like Zhang Zai and the Cheng brothers on the identity of mind and trace and the unity of void and solid are mutually manifested. The same mind with the same principle means “mind is principle.” The “common axis of Confucianism and Buddhism” exists in the emphasis on mind beyond trace. The unification of mind and trace or the accordance of body and function has actually become the cardinal foundation for the possible mergence of the Three Teachings.     

Kernel smoothing approaches to nonparametric item characteristic curve estimation

The option characteristic curve, the relation between ability and probability of choosing a particular option for a test item, can be estimated by nonparametric smoothing techniques. What is smoothed is the relation between some function of estimated examinee ability rankings and the binary variable indicating whether or not the option was chosen. This paper explores the use of kernel smoothing, which is particularly well suited to this application. Examples show that, with some help from the fast Fourier transform, estimates can be computed about 500 times as rapidly as when using commonly used parametric approaches such as maximum marginal likelihood estimation using the three-parameter logistic distribution. Simulations suggest that there is no loss of efficiency even when the population curves are three-parameter logistic. The approach lends itself to several interesting extensions.The author wishes to acknowledge the support of the National Sciences and Engineering Research Council of Canada through grant A320 and the support of Educational Testing Service during his leave there.     

Searching for the Trace: The Influence of Age, Lexical Activation and Working Memory on Sentence Processing

To investigate the stability of trace reactivation in healthy older adults, 22 older volunteers with no significant neurological history participated in a cross-modal priming task. Whilst both object relative center embedded (ORC) and object relative right branching (ORR) sentences were employed, working memory load was reduced by limiting the number of words separating the antecedent from the gap for both sentence types. Analysis of the results did not reveal any significant trace reactivation for the ORC or ORR sentences. The results did reveal, however, a positive correlation between age and semantic priming at the pre-gap position and a negative correlation between age and semantic priming at the gap position for ORC sentences. In contrast, there was no correlation between age and priming effects for the ORR sentences. These results indicated that trace reactivation may be sensitive to a variety of age related factors, including lexical activation and working memory. The implications of these results for sentence processing in the older population are discussed.     

Memory retrieval as a self-propagating process

Retrieval of a subset of studied items and the presentation of those items as retrieval cues typically impair retrieval of the other items. Previous research on this self-limiting property of memory retrieval has relied heavily on short retention intervals and similar context between encoding and test. Here, we examined retrieval dynamics also after a prolonged retention interval with different spatial and social context between encoding and test, conditions that mimic people’s remembering in many situations of daily life. For both unrelated word lists and more integrated prose material, we found retrieval and cuing to impair recall of other studied items after a short retention interval, but to improve recall in the prolonged retention interval condition. The results demonstrate that retrieval dynamics depend critically on situation, indicating that quite often in daily life, retrieval may be a self-propagating, rather than a self-limiting process.