Selective Revision

We introduce a constructive model of selective belief revision in which it is possible to accept only a part of the input information. A selective revision operator ο is defined by the equality K ο α = K * f(α), where * is an AGM revision operator and f a function, typically with the property ⊢ α → f(α). Axiomatic characterizations are provided for three variants of selective revision. This revised version was published online in June 2006 with corrections to the Cover Date.     

Bias in visual attention behavior in a normal school-aged population

Hemi-field visual-spatial attention was studied on a timed letter cancellation task in proficient readers from 7th to 9th grades. Participants maintained greater accuracy in identifying targets in the left quadrants (top/bottom) when compared with the right quadrants (top/bottom), revealing a leftward bias in their responses. Effects of gender and age were evident on performance; females scored significantly higher than males, and 9th graders scored significantly higher than 7th and 8th graders. Thus, a substantial shift in brain maturation may take place from 8th to 9th grades or from the ages of 13.0 to 14.11. Discriminative characteristics of the task are analyzed by assigning greater value to targets located in the top left quadrant. The 9th graders, as compared to the younger students, and the girls, as compared to the boys, evidenced a reading-direction-related bias toward systematic preference for the upper-left to lower-right quadrants.     

The hippocampus and memory of verbal and pictorial material

Recognition of words and kaleidoscope pictures showed a double dissociation of left and right hippocampal activity using magnetic source imaging (MSI). MSI has advantages over alternative imaging techniques that measure hemodynamic changes for identifying regional changes in brain activity in real time and on an individual subject basis without the need for image subtraction. In this study, lists of words or kaleidoscope pictures were presented for memorization followed by tests of list items and foils during which brain activity was recorded. There was greater activation in the left than the right hippocampus with abstract nouns (e.g., relief) and greater activation in the right than the left hippocampus with kaleidoscope pictures. This dissociation was evident on a case by case basis. This study demonstrates the specialization of the two medial temporal lobe (MTL) regions, including the hippocampi, for mnemonic processing of verbal and pictorial items that are difficult to encode verbally.     

Is it Morally Wrong to Defend Unjust Causes as a Lawyer?

The question I address in this article is whether it is morally wrong for a lawyer to represent a client whose purpose is immoral or unjust. My answer to this question is that it is wrong, prima facie. This conclusion holds, even accepting certain traditional principles of lawyer's professional ethics, such as the right of defence and the so‐called principle of ‘adversarial’ litigation. Both the adversarial system and the right of defence are sufficient to support or justify the right of potential clients (and citizens in general) to defend their interests in the judicial system and to do so with the technical assistance of a lawyer. This right includes a right to pursue unjust or immoral purposes (within the law). However, having a right to do X does not mean that it is morally permissible to do X. We can have a right to do something morally wrong. This being so, the fundamental moral reason for a lawyer not to accept representation for a client with an immoral purpose is that it is, prima facie, morally wrong to help someone do something wrong.     

THE EVOLUTION OF HUMAN BIRTH AND TRANSHUMANIST PROPOSALS OF ENHANCEMENT

Some transhumanists argue that we must engage with theories and facts about our evolutionary past in order to promote future enhancements of the human body. At the same time, they call our attention to the flawed character of evolution and argue that there is a mismatch between adaptation to ancestral environments and contemporary life. One important trait of our evolutionary past which should not be ignored, and yet may hinder the continued perfection of humankind, is the peculiarly human way of bearing and raising children. The suffering associated with childbirth and a long childhood have demanded trade‐offs that have enhanced our species, leading to cooperation, creativity, intelligence and resilience. Behaviors such as mother–infant engagement, empathy, storytelling, and ritual have also helped to create what we value most in human beings. Therefore, the moral, cognitive, and emotional enhancements proposed by these transhumanists may be impaired by their partial appropriation of evolution, insofar as the bittersweet experience of parenthood is left aside.     

The Logics of Strict-Tolerant Logic

Adding a transparent truth predicate to a language completely governed by classical logic is not possible. The trouble, as is well-known, comes from paradoxes such as the Liar and Curry. Recently, Cobreros, Egré, Ripley and van Rooij have put forward an approach based on a non-transitive notion of consequence which is suitable to deal with semantic paradoxes while having a transparent truth predicate together with classical logic. Nevertheless, there are some interesting issues concerning the set of metainferences validated by this logic. In this paper, we show that this logic, once it is adequately understood, is weaker than classical logic. Moreover, the logic is in a way similar to the paraconsistent logic LP.     

Symbolic representation of the number three: a study with three-year-old children from contrasting socioeconomic environments

The goal of the present study was to compare a range of aspects in children’s symbolic knowledge about the number three among two groups of three-year-olds from contrasting socioeconomic backgrounds. Every child was presented with five tasks that focused on the number three and that had cognitive demands of different complexity: expressing their age, reciting the conventional number series up to three, quantifying a collection of three, and two tasks requiring the use of visually presented quantitative information.The results showed the same order of difficulty of the tasks in both socioeconomic groups and a clear performance difference depending on socioeconomic background. These findings show that symbolic knowledge about the number three does not come in an all or none fashion. Rather, different aspects of this symbolic competence become apparent in response to different tasks, and seem to depend largely on the socioeconomic environment in which children develop.