Three Approaches to Iterated Belief Contraction

In this paper we investigate three approaches to iterated contraction, namely: the Moderate (or Priority) contraction, the Natural (or Conservative) contraction, and the Lexicographic contraction. We characterise these three contraction functions using certain, arguably plausible, properties of an iterated contraction function. While we provide the characterisation of the first two contraction operations using rationality postulates of the standard variety for iterated contraction, we found doing the same for the Lexicographic contraction more challenging. We provide its characterisation using a variation of Epistemic ranking function instead.     

Belief change as change in epistemic entrenchment

In this paper, it is argued that both the belief state and its input should be represented as epistemic entrenchment (EE) relations. A belief revision operation is constructed that updates a given EE relation to a new one in light of an evidential EE relation, and an axiomatic characterization of this operation is given. Unlike most belief revision operations, the one developed here can handle both multiple belief revision and iterated belief revision.The authors are thankful to John G. Bennett, Henry E. Kyburg, Jr., Norman Foo, Pavlos Pepas, Maurizio Pagnucco, Bob Hadley, members of the Knowledge Systems Group at the University of Sydney and participants of the AI'93 workshop on Belief Revision: Bridging the Gap Between Theory and Practice at Melbourne where a version of this paper was presented, for their suggestions. The authors also express their gratitude to the two anonymous referees for Synthese for their excellent comments and suggestions. Of course it is only the authors that are responsible for the errors that remain.     

Conceptual knowledge in the interpretation of idioms

The authors examined how people determine the contextual appropriateness of idioms. In Experiment 1, idioms referring to the same temporal stage of a conceptual prototype were judged to be more similar in meaning than idioms referring to different temporal stages. In Experiment 2, idioms in a prototypical temporal sequence were more meaningful than idioms in sentences that violated the temporal sequence. In Experiment 3, idioms referring to the same stage of a conceptual prototype were differentiable on the basis of conceptual information. The conceptual coherence between idioms and contexts facilitated the processing speed of idioms in Experiment 4. Experiment 5 showed that speakers can recover the underlying conceptual metaphors that link an idiom to its figurative meaning. Experiment 6 showed that the metaphoric information reflected in the lexical makeup of idioms also determined the metaphoric appropriateness of idioms in certain contexts.     

Speakers' assumptions about the lexical flexibility of idioms

In three experiments, we examined why some idioms can be lexically altered and still retain their figurative meanings (e.g., John buttoned his lips about Mary can be changed into John fastened his lips about Mary and still mean "John didn't say anything about Mary"), whereas other idioms cannot be lexically altered without losing their figurative meanings (e.g., John kicked the bucket, meaning "John died," loses its idiomatic meaning when changed into John kicked the pail). Our hypothesis was that the lexical flexibility of idioms is determined by speakers' assumptions about the ways in which parts of idioms contribute to their figurative interpretations as a whole. The results of the three experiments indicated that idioms whose individual semantic components contribute to their overall figurative meanings (e.g., go out on a limb) were judged as less disrupted by changes in their lexical items (e.g., go out on a branch) than were nondecomposable idioms (e.g., kick the bucket) when their individual words were altered (e.g., punt the pail). These findings lend support to the idea that both the syntactic productivity and the lexical makeup of idioms are matters of degree, depending on the idioms' compositional properties. This conclusion suggests that idioms do not form a unique class of linguistic items, but share many of the properties of more literal language.     

Foundational belief change

This paper is concerned with the construction of a base contraction (revision) operation such that the theory contraction (revision) operation generated by it will be fully AGM-rational. It is shown that the theory contraction operation generated by Fuhrmann'sminimal base contraction operation, even under quite strong restrictions, fails to satisfy the supplementary postulates of belief contraction. Finally Fuhrmann's construction is appropriately modified so as to yield the desired properties. The new construction may be described as involving a modification of safe (base) contraction so as to make it maxichoice.     

Iterated belief change based on epistemic entrenchment

In this paper it is argued that, in order to solve the problem of iterated belief change, both the belief state and its input should be represented as epistemic entrenchment (EE) relations. A belief revision operation is constructed that updates a given EE relation to a new one in light of an evidential EE relation. It is shown that the operation in question satisfies generalized versions of the Gärdenfors revision postulates. The account offered is motivated by Spohn's ordinal conditionalization functions, and can be seen as the Jeffrization of a proposal considered by Rott.I am indebted John G. Bennett and Henry E. Kyburg. jr. for their insightful comments on an earlier draft of this paper. I thank the referees forErkenntnis who, apart from giving extended comments and suggestions, provided me with some hard-to-find relevant material. I also thank Prashanta Bandyopadhyay, Norman Foo, Maurice Pagnucco, Hans Rott and Mary-Anne Williams for their suggestions. The errors that remain are, of course, mine.     

The relationship of childhood trauma to nicotine dependence in pregnant smokers

Pregnant women with high levels of nicotine dependence are the least likely to quit smoking spontaneously during pregnancy or to benefit from smoking cessation interventions. In the general population, there is increasing evidence of a relationship between smoking, nicotine dependence, and exposure to childhood trauma. We examined the relationship of childhood trauma to several measures of nicotine dependence and evaluated whether this relationship was mediated by major depressive disorder or depressive symptom severity in pregnant smokers. Moderate to extreme levels of childhood trauma were significantly related to smoking within 5 minutes or less of waking, and to the Behavioral Choice-Melioration, Negative Reinforcement, and Tolerance subscales of the Wisconsin Inventory of Smoking Dependence Motives (WISDM-68) scale. The relationships between childhood emotional abuse and the WISDM-68 Total and Negative Reinforcement subscale were partially mediated by depressive symptoms. Results suggest that childhood trauma may be a risk factor underlying nicotine dependence in pregnant smokers. Increased understanding of the relationship of affect regulation to smoking in individuals with childhood trauma histories may aid in the development of more effective treatments of nicotine dependence for this population of smokers.     

Attitudes Toward Violence Against Women: A Cross-Nation Study

An understanding of attitudes toward violence against women is vital for effective prevention strategies. In this study we examined attitudes regarding violence against women in samples of undergraduate women and men students from four countries: India, Japan, Kuwait, and the United States. Attitudes toward sexual assault and spousal physical violence differed between men and women and across the four countries. Variations in gender differences across countries indicated that, for attitudes regarding sexual assault of women in particular, sociocultural factors may be a stronger influence than gender. Findings suggest the importance of examining differences within the larger sociocultural context of political, historical, religious, and economic influences on attitudes toward gender roles and violence against women.     

Performance Effects of Reward-Related Feedback on the Dimensional Change Card Sort Task

The Dimensional Change Card Sort (DCCS) is one of the most widely used measures of preschool executive function, yet relatively little is known about how altering emotional demands of the task affects DCCS performance. This study examined the effects of emotionally evocative reward-related feedback on preschool children's performance on the DCCS in a sample of 105 children aged 3.5–4.5 years. In a within-subjects design, children completed the standard DCCS and a modified version of the DCCS in which sticker rewards were gained or lost after each trial. With a reward at stake, children were more accurate but had slower reaction time on the post-switch DCCS. Another sample (N = 20) of 3.5- to 4.5-year-olds who completed the standard DCCS twice without reward showed no change in performance, indicating results are not due to practice effects. Findings demonstrate preschool children's ability to adjust their approach to the DCCS in the presence of emotionally evocative reward-related feedback by prioritizing accuracy over speed. Trial-by-trial reward-related feedback may facilitate cognitive control in early childhood.     

Gricean Belief Change

One of the standard principles of rationality guiding traditional accounts of belief change is the principle of minimal change: a reasoner's belief corpus should be modified in a minimal fashion when assimilating new information. This rationality principle has stood belief change in good stead. However, it does not deal properly with all belief change scenarios. We introduce a novel account of belief change motivated by one of Grice's maxims of conversational implicature: the reasoner's belief corpus is modified in a minimal fashion to assimilate exactly the new information. In this form of belief change, when the reasoner revises by new information p ∨ q their belief corpus is modified so that p∨q is believed but stronger propositions like p∧q are not, no matter what beliefs are in the reasoner's initial corpus. We term this conservative belief change since the revised belief corpus is a conservative extension of the original belief corpus given the new information.