Common Representations of Abstract Quantities

ABSTRACT— Representations of abstract quantities such as time and number are essential for survival. A number of studies have revealed that both humans and nonhuman animals are able to nonverbally estimate time and number; striking similarities in the behavioral data suggest a common magnitude-representation system shared across species. It is unclear, however, whether these representations provide animals with a true concept of time and number, as posited by Gallistel and Gelman (2000) . In this article, we review the prominent cognitive and neurobiological models of timing and counting and explore the current evidence suggesting that nonhuman animals represent these quantities in a modality-independent (i.e., abstract) and ordered manner. Avenues for future research in the area of temporal and mathematical cognition are also discussed.     

What Are Degrees of Belief?

Probabilism is committed to two theses:

Consistency Defaults

A consistency default is a propositional inference rule that asserts the consistency of a formula in its consequence. Consistency defaults allow for a straightforward encoding of domains in which it is explicitely known when something is possible. The logic of consistency defaults can be seen as a variant of cumulative default logic or as a generalization of justified default logic; it is also able to simulate Reiter default logic in the seminormal case. A semantical characterization of consistency defaults in terms of processes and in terms of a fixpoint equation is given, as well as a normal form. Presented by Melvin Fitting     

Adolescent development of motor imagery in a visually guided pointing task

The development of action representation during adolescence was investigated using a visually guided pointing motor task (VGPT) to test motor imagery. Forty adolescents (24 males; mean age 13.1 years) and 33 adults (15 males; mean age 27.5 years) were instructed to both execute and imagine hand movements from a starting point to a target of varying size. Reaction time (RT) was measured for both Execution (E) and Imagery (I) conditions. There is typically a close association between time taken to execute and image actions in adults because action execution and action simulation rely on overlapping neural circuitry. Further, representations of actions are governed by the same speed-accuracy trade-off as real actions, as expressed by Fitts’ Law. In the current study, performance on the VGPT in both adolescents and adults conformed to Fitts’ Law in E and I conditions. However, the strength of association between E and I significantly increased with age, reflecting a refinement in action representation between adolescence and adulthood.     

Reason,Representation, and Participation

This paper argues that the contrast between direct and representative democracy is less important than that between simple majoritarianism and deliberative i.e., public reason centred, democracy, as only the latter is sufficiently sensitive to the problem of domination. Having explored a range of arguments in favour of direct democracy it is argued that moves in this direction are only warranted when the practice of public reasoning will be enhanced. Both symbolic representation and delegate democracy are rejected in favour of substantive measures to formalise communication between voters and representatives and permit the formal contestation of political decision on the ground that these will provide stronger defences against domination within the political system.     

Feature binding in visual working memory evaluated by type identification paradigm

Memory for feature binding comprises a key ingredient in coherent object representations. Previous studies have been equivocal about human capacity for objects in the visual working memory. To evaluate memory for feature binding, a type identification paradigm was devised and used with a multiple-object permanence tracking task. Using objects defined by shape and color, observers identified types of changes in feature combinations across an occlusion event, and the effects of object motion and number of switches were investigated. With only one switch, task performance was impaired even under stationary conditions, suggesting highly limited capacity of binding memory. Second switch improved performance only in the stationary condition, suggesting that object motion strongly disrupts feature binding. Further analyses and experiments suggest that improvement by the second switch reflects transition of binding memory by selective attention.     

区分度在面部表情与面孔身份识别交互中的作用

已有研究表明,身份对面部表情识别的影响较常见,但表情对面孔身份识别的影响却很罕见。只有个别研究发现了表情对熟悉面孔身份识别的影响。最近有研究使用非常相似的模特面孔图片为实验材料,也发现了表情对身份识别的影响,并提出在以往研究中表情不影响身份识别是因为身份的区分度高于表情的区分度。本研究置疑表情区分度低于身份区分度的必然性,认为过去的研究使用静态表情图片,使得表情自然具有的强度变化线索缺失,才导致表情的区分度相对较低。本研究假设,当表情的强度变化线索得以体现时,表情的区分度就会提高,此时表情识别可能就不会受身份的影响。实验结果支持该假设,证明表情与身份的区分度水平是决定二者识别交互模式的重要因素。表情身份识别之间的相互影响并不能完全证明这两者之间的独立加工关系。此外,研究结果也提示在一定条件下可以部分分离表情与身份信息     

表征与认知发展

One of the major divergences between dynamical systems theory and symbolism lies in their views on the role of representation in cognition. From the perspective of development, the cognitive development could be divided into three levels: sensorimotor, imagery representation and linguistic representation. It is claimed that representation is not a sufficient condition though it is necessary for cognition. However, it does not mean that the authors agree with the notion of strong coupling in dynamicism that completely rejects representation. Translated by Wang Xiaolu, Xiao Jiayan and Li Hengwei from Zhongguo Shehui Kexue 中国社会科学 (Social Sciences in China), 2006, (2): 34–44     

统计认知理论及应用研究

长期以来大家认为人类认知尽管可以看成是非确定的推理计算过程,但它的知识表达、模型结构、及计算方法和概率统计理论在本质上是不同的,因此认知科学和概率统计方法存在巨大的鸿沟,过去两者基本上独立发展。近年来随着Bayesian概率统计模型研究的一系列突破性工作和认知过程本质的不断被发现和挖掘,两者的相关性和互补性逐渐突显出来。许多研究者认为认知是近似遵循概率统计推理原则的,一些研究工作显示两者的结合有可能对人工智能发展产生深远的影响。本文对当前统计认知理论及应用研究的现状进行系统的梳理,并结合自身的研究对它今后的发展提出自己的看法。