Overshadowing by fixed- and variable-duration stimuli

Two experiments investigated the effect of the temporal distribution form of a stimulus on its ability to produce an overshadowing effect. The overshadowing stimuli were either of the same duration on every trial, or of a variable duration drawn from an exponential distribution with the same mean duration as that of the fixed stimulus. Both experiments provided evidence that a variable-duration stimulus was less effective than a fixed-duration cue at overshadowing conditioning to a target conditioned stimulus (CS); moreover, this effect was independent of whether the overshadowed CS was fixed or variable. The findings presented here are consistent with the idea that the strength of the association between CS and unconditioned stimulus (US) is, in part, determined by the temporal distribution form of the CS. These results are discussed in terms of time-accumulation and trial-based theories of conditioning and timing.     

Can children resist making interpretations when uncertain?

In two experiments, we examined young children's ability to delay a response to ambiguous input. In Experiment 1, 5- and 6-year-olds performed as poorly when they needed to choose between basing an interpretation on ambiguous input and delaying an interpretation as when making explicit evaluations of knowledge, whereas 7- and 8-year-olds found the former task easy. In Experiment 2, 5- and 6-year-olds performed well on a task that required delaying a response but removed the need to decide between strategies. We discuss children's difficulty with ambiguity in terms of the decision-making demands made by different procedures. These demands appear to cause particular problems for young children.     

Hidden consequences of the group-serving bias: Causal attributions and the quality of group decision making

A long stream of research in attribution theory suggests that groups are biased toward attributing their success to factors that are internal to their group. However, the existing research has confounded two types of attributions that are both internal to the group, but theoretically distinct: (1) attributions that differentiate between the contributions made by each individual group member and (2) attributions that focus on the group as a whole. This dichotomy is important because, drawing on theories of social influence, we predict that different types of attributions will have different consequences for the quality of group decision making. In Experiment 1, individually focused attributions for past success caused groups to consider more divergent alternatives prior to making a shared decision. In Experiment 2, individually focused attributions for past success facilitated the sharing of unique information and improved decision accuracy. These findings suggest that the group-serving tendency to internalize success may have important consequences for group performance that have not yet been considered in current research.     

Revisiting the university front

The article argues that the most important trends in the recent metamorphosis of higher education, especially of university teaching and research, cannot be understood without placing them in the context of general developments in political life. Both processes reveal alarming features and there is a link between them. In recent decades a religion has established its dominance in the public policy field. Its dogmas are called “liberalization”, “economic man”, “individual preference”, “the free market”, “competition” and “efficiency”. The consequences of the progressive imposition of this doctrine on the universities—including on the relation between teaching and research—are well documented but not always well understood. It is argued that the “commercialization” of higher education and research means in reality their hyper-bureaucratization, via the imposition of so-called evaluation, assessment and accreditation schemes, the latest avatars of the managerialist ideology. Might the final result be the disintegration of the university as an institution?     

Knowledge,adequacy, and approximate truth

Approximation involves representing things in ways that might be close to the truth but are nevertheless false. Given the widespread reliance on approximations in science and everyday life, here we ask whether it is conceptually possible for false approximations to qualify as knowledge. According to the factivity account, it is impossible to know false approximations, because knowledge requires truth. According to the representational adequacy account, it is possible to know false approximations, if they are close enough to the truth for present purposes. In this paper, we adopt an experimental methodology to begin testing these two theories. When an agent provides a false and practically inadequate answer, both theories predict that people will deny knowledge. But the theories disagree about an agent who provides a false but practically adequate answer: the factivity hypothesis again predicts knowledge denial, whereas the representational adequacy hypothesis predicts knowledge attribution. Across two experiments, our principal finding was that people tended to attribute knowledge for false but practically adequate answers, which supports the representational adequacy account. We propose an interpretation of existing findings that preserves a conceptual link between knowledge and truth. According to this proposal, truth is not necessary for knowledge, but it is a feature of prototypical knowledge.     

The One-to-One Constraint in Analogical Mapping and Inference

Theories of analogical reasoning have assumed that a 1-to-1 constraint discourages reasoners from mapping a single element in 1 analog to multiple elements in another. Empirical evidence suggests that reasoners sometimes appear to violate the one-to-one constraint when asked to generate mappings, yet virtually never violate it when asked to generate analogical inferences. However, few studies have examined analogical inferences based on nonisomorphic analogs, and their conclusions are suspect due to methodological problems. We sought to elicit mixed inferences that could result from combining information from 2 possible mappings. Participants generated 2-to-1 correspondences when asked for explicit mappings, but did not produce mixed inferences. Multiple correspondences appear to arise from multiple isomorphic mappings, rather than from a single homomorphic mapping.     

现代医学人文回归的学术性与现实性

以生物-心理-社会医学模式为背景,以哲学和生态审美理论为起点,提出了"医学人文精神"、"医学人文关怀"等概念,在此基础上,分析了医学人文回归的内容及其与医学审美之间的内在联系.从学术性和现实性两个层面,针对我国存在的医学人文缺失的现状,分析了以"三观"(生命观、健康的可持续发展观、科学观)为基础的人文信仰的内容、功能与意义,以及如何从内容与形式辩证统一的审美视角出发,运用美的规律去改善、丰富和提升医学人文关怀的境界.     

近现代中西医教育课程内容和教育形式的演变

近现代的中西医教育从课程内容和学位教育形式方面表现出完全不同的发展态势,主要原因是在中西医的学术内部.中医学理论属于哲学范畴,缺少自我更新的能力,只停留在形式上的表面进步.而西医学是以自然科学为基础,科技水平的进步也会带动其迅速发展.这就是当前中医教育面临的结症所在,需要中医人士潜心研究,为中医教育开辟新路.     

The effects of prior knowledge on children's memory and suggestibility

In this study, 5- and 6-year-olds were read a story and asked to recall its details. Two independent factors-prestory knowledge and poststory suggestions-were crossed to examine the effects on children's story recall. The results indicated that prestory social knowledge about the story protagonist as well as academic knowledge relating to the content of the story influenced the accuracy of children's recall immediately after the story presentation. Following the suggestive interview, children reported interviewer-provided social and academic misinformation to a greater extent when the misinformation was consistent with their prior knowledge. In contrast, children were more likely to refute misinformation that contradicted their academic knowledge. These findings are discussed in terms of the mechanisms underlying the knowledge-memory and knowledge-suggestibility linkages.     

Modeling parallelization and flexibility improvements in skill acquisition: from dual tasks to complex dynamic skills

Emerging parallel processing and increased flexibility during the acquisition of cognitive skills form a combination that is hard to reconcile with rule-based models that often produce brittle behavior. Rule-based models can exhibit these properties by adhering to 2 principles: that the model gradually learns task-specific rules from instructions and experience, and that bottom-up processing is used whenever possible. In a model of learning perfect time-sharing in dual tasks (Schumacher et al., 2001), speedup learning and bottom-up activation of instructions can explain parallel behavior. In a model of a complex dynamic task (Carnegie Mellon University Aegis Simulation Program [CMU-ASP], Anderson et al., 2004), parallel behavior is explained by the transition from serially organized instructions to rules that are activated by both top-down (goal-driven) and bottom-up (perceptually driven) factors. Parallelism lets the model opportunistically reorder instructions, leading to the gradual emergence of new task strategies.