On the Compositional Extension Problem

A semantics may be compositional and yet partial, in the sense that not all well-formed expressions are assigned meanings by it. Examples come from both natural and formal languages. When can such a semantics be extended to a total one, preserving compositionality? This sort of extension problem was formulated by Hodges, and solved there in a particular case, in which the total extension respects a precise version of the fregean dictum that the meaning of an expression is the contribution it makes to the meanings of complex phrases of which it is a part. Hodges' result presupposes the so-called Husserl property, which says roughly that synonymous expressions must have the same category. Here I solve a different version of the compositional extension problem, corresponding to another type of linguistic situation in which we only have a partial semantics, and without assuming the Husserl property. I also briefly compare Hodges' framework for grammars in terms of partial algebras with more familiar ones, going back to Montague, which use many-sorted algebras instead.

     

Book Reviews

Books reviewed:
James Campbell, Recovering Benjamin Franklin
Elliot L. Jurist, Beyond Hegel and Nietzsche: Philosophy, Culture, and Agency     

视知觉组织在整体知觉中的作用--脑损伤病人的实验研究

本实验研究大脑损伤如何影响复合图形的整体知觉。三例病人脑损伤部位分别在大脑枕区、顶区、颞区、额区及基底节和豆状核。复合图形被呈现给病人和正常对照被试。强迫选择识别等任务表明,当空间相邻性决定局部图形的知觉组织时,病人识别整体性质的正确率高于(ZD和FL)或略底于(GK)识别局部性质的正确率;当形状相似性决定局部图形的知觉组织时,病人识别整体性质的正确率显著降低,而识别局部性质的正确率受到的影响较小。在同样的任务中正常被试识别整体和局部性质的正确率受知觉组织因素的影响很小。这些结果提示大脑损伤对整体知觉的破坏可能主要通过影响基于形状相似性的知觉组织实现。     

Products of Modal Logics. Part 3: Products of Modal and Temporal Logics

In this paper we improve the results of [2] by proving the product f.m.p. for the product of minimal n-modal and minimal n-temporal logic. For this case we modify the finite depth method introduced in [1]. The main result is applied to identify new fragments of classical first-order logic and of the equational theory of relation algebras, that are decidable and have the finite model property.     

Recognition of natural scenes from global properties: seeing the forest without representing the trees

Human observers are able to rapidly and accurately categorize natural scenes, but the representation mediating this feat is still unknown. Here we propose a framework of rapid scene categorization that does not segment a scene into objects and instead uses a vocabulary of global, ecological properties that describe spatial and functional aspects of scene space (such as navigability or mean depth). In Experiment 1, we obtained ground truth rankings on global properties for use in Experiments 2-4. To what extent do human observers use global property information when rapidly categorizing natural scenes? In Experiment 2, we found that global property resemblance was a strong predictor of both false alarm rates and reaction times in a rapid scene categorization experiment. To what extent is global property information alone a sufficient predictor of rapid natural scene categorization? In Experiment 3, we found that the performance of a classifier representing only these properties is indistinguishable from human performance in a rapid scene categorization task in terms of both accuracy and false alarms. To what extent is this high predictability unique to a global property representation? In Experiment 4, we compared two models that represent scene object information to human categorization performance and found that these models had lower fidelity at representing the patterns of performance than the global property model. These results provide support for the hypothesis that rapid categorization of natural scenes may not be mediated primarily though objects and parts, but also through global properties of structure and affordance.     

Does language about similarity play a role in fostering similarity comparison in children?

Commenting on perceptual similarities between objects stands out as an important linguistic achievement, one that may pave the way towards noticing and commenting on more abstract relational commonalities between objects. To explore whether having a conventional linguistic system is necessary for children to comment on different types of similarity comparisons, we observed four children who had not been exposed to usable linguistic input - deaf children whose hearing losses prevented them from learning spoken language and whose hearing parents had not exposed them to sign language. These children developed gesture systems that have language-like structure at many different levels. Here we ask whether the deaf children used their gestures to comment on similarity relations and, if so, which types of relations they expressed. We found that all four deaf children were able to use their gestures to express similarity comparisons (point to cat + point to tiger) resembling those conveyed by 40 hearing children in early gesture + speech combinations (cat + point to tiger). However, the two groups diverged at later ages. Hearing children, after acquiring the word like, shifted from primarily expressing global similarity (as in cat/tiger) to primarily expressing single-property similarity (as in crayon is brown like my hair). In contrast, the deaf children, lacking an explicit term for similarity, continued to primarily express global similarity. The findings underscore the robustness of similarity comparisons in human communication, but also highlight the importance of conventional terms for comparison as likely contributors to routinely expressing more focused similarity relations.     

Equivalents for a Quasivariety to be Generated by a Single Structure

We present some equivalent conditions for a quasivariety of structures to be generated by a single structure. The first such condition, called the embedding property was found by A.I. Mal′tsev in [6]. It says that if are nontrivial, then there exists such that A and B are embeddable into C. One of our equivalent conditions states that the set of quasi-identities valid in is closed under a certain Gentzen type rule which is due to J. Łoś and R. Suszko [5]. Presented by Jacek Malinowski     

选择、自我表达与选择扩散效应

自我表达会影响西方人的态度, 产生选择扩散效应。国外相关的跨文化研究发现东方人不存在该效应。通过4个实验研究中国文化下自我表达对选择态度的影响, 发现选择方式(主动、被动)和自我表达形式(直接、间接)对选择态度产生影响。无论是自己的主动选择还是强加的被动选择, 直接的自我表达会增加对所获对象的喜爱程度, 表现为对获得性的肯定。研究者认为, 两种选择方式下不同的心理加工过程导致了这种获得性：直接表达使个人态度暴露在外, 进行主动选择时要对他人的给予做出肯定回应; 而进行被动选择时, 人们要减缓因利益受损可能导致的失调, 同时中国文化下的面子策略也使人们增加对所获对象的喜爱程度。不过, 间接的自我表达对选择态度的影响不明显。研究者认为, 多个影响因素的相互消长使选择态度得以维持。     

Need for uniqueness,self-schemas,and thought as moderators of the false-consensus effect

L. Ross and his colleagues (L. Ross, D. Greene, & P. House, 1977, Journal of Experimental Social Psychology, 32, 880–892) have demonstrated the tendency for people to expect peer similarity in behavior, termed the “false-consensus” bias. The present study was concerned with factors that might affect the generality of this bias. Specifically, we looked at the impact of level of need for uniqueness (C. R. Snyder & H. L. Fromkin, 1977, Journal of Abnormal Psychology, 5, 518–527), existence of a self-schema (H. Markus, 1977, Journal of Personality and Social Psychology, 35, 63–78), and thought on expectations of peer similarity. It was predicted that thought would polarize the estimates of high and low N Uniq individuals in opposite directions, but only when the individual possessed a self-schema along the relevant behavioral dimension. The results for behaviors reflecting independence supported this prediction. Discussion centered around limits of the false-consensus bias, along with consideration of the complexities involved in the link between availability factors and interpersonal judgments.     

Self-consciousness and aspects of identity

This study investigated the relationship between public and private self-consciousness and social and personal aspects of identity. As predicted by self-consciousness theory, public self-consciousness correlated significantly more strongly with social than with personal aspects of identity, and private self-consciousness correlated significantly more strongly with personal than with social aspects of identity. Implications for the psychology of identity are discussed.