Conditioned taste aversion modifies persistently the subsequent induction of neocortical long-term potentiation in vivo

The ability of neurons to modify their synaptic strength in an activity-dependent manner has a crucial role in learning and memory processes. It has been proposed that homeostatic forms of plasticity might provide the global regulation necessary to maintain synaptic strength and plasticity within a functional dynamic range. Similarly, it is considered that the capacity of synapses to express plastic changes is itself subject to variation dependent on previous experience. In particular, training in several behavioral tasks modifies the possibility to induce long-term potentiation (LTP). Our previous studies in the insular cortex (IC) have shown that induction of LTP in the basolateral amygdaloid nucleus (Bla)-IC projection previous to conditioned taste aversion (CTA) training enhances the retention of this task. The aim of the present study was to analyze whether CTA training modifies the ability to induce subsequent LTP in the Bla-IC projection in vivo. Thus, CTA trained rats received high frequency stimulation in the Bla-IC projection in order to induce LTP 48, 72, 96 and 120 h after the aversion test. Our results show that CTA training prevents the subsequent induction of LTP in the Bla-IC projection, for at least 120 h after CTA training. We also showed that pharmacological inhibition of CTA consolidation with anisomycin (1 μl/side; 100 μg/μl) prevents the CTA effect on IC-LTP. These findings reveal that CTA training produces a persistent change in the ability to induce subsequent LTP in the Bla-IC projection in a protein-synthesis dependent manner, suggesting that changes in the ability to induce subsequent synaptic plasticity contribute to the formation and persistence of aversive memories.     

ABILITIES OF TWINS

The investigation concerns two main problems: (1) the distribution of ability test scores among twins in comparison with single-borns; and (2) intra-pair similarity among the various twin categories. More than 1000 individual twins were compared with 2700 single-borns on 21 test variables covering Swedish, Mathematics and English. The twin group consistently showed a lower average than the single-borns due to a displacement of the test score distribution as a whole among twins. The intra-pair similarities, expressed as intra-class correlations, run between 0.85 and 0.90 for identical pairs, whereas like-sex fraternals showed coefficients about 0.60. The unlike-sex fraternals had coefficients ten to twenty hundredths lower than those of the like-sex pairs.     

The Fundamental Problem of Logical Omniscience

Journal of Philosophical Logic - We propose a solution to the problem of logical omniscience in what we take to be its fundamental version: as concerning arbitrary agents and the knowledge attitude...     

Dialogue and Dominance in Couple Therapy for Depression: Exploring Therapists’ Responses in Creating Collaborative Moments

Previous investigations have found specific communication patterns in couples dealing with depression, specifically when depression concurs with conjugal conflicts. The presence of these patterns can reflect couples’ difficulties in engaging in collaborative communication during their sessions, posing a real challenge for therapists. This exploratory study uses a dialogical approach to examine issues of dominance and type of dialogue in two couples who differed in terms of their levels of dyadic adjustment. The therapists’ reactions were explored in order to detect the kinds of responses that were most effective at engendering a collaborative attitude in therapy sessions. The method used to analyze the dialogue was Dialogical Investigations of Happenings of Change (DIHC). Results on dominance indicated that the degree of quantitative and semantic dominance displayed by a different member of the couple in each case was illustrative of their relational dynamics, while in both cases interactional dominance was exercised by the therapists. Results on dialogue revealed that dialogic dialogue might help to coconstruct new shared meanings of depression. The findings indicated that certain responses by therapists as part of the dialogue could be useful in bringing about a reduction in hostility between the members of a couple, provided that the responses are maintained over the course of the session. Some research and clinical implications that emerge from the results are discussed.     

On Potentiality And Respect For Embryos: A Reply To Mary Mahowald

In order to understand the nature of human embryos I first distinguish between active and passive potentiality, and then argue that the former is found in human gametes and embryos (even in embryos in vitro that may fail to be implanted) because they all have an indwelling power or capacity to initiate certain changes. Implantation provides necessary conditions for the actualization of that prior, active potentiality. This does not imply that embryos are potential persons that do not deserve the same respect as actual persons. To claim that embryos become persons is to understand the predicate person as a phase sortal, roughly equivalent to adult person. This entails that we would not be essentially persons. In order to explain the traditional understanding of person as a proper sortal rather than a phase sortal, the author distinguishes between proximate and remote potentiality, and shows that, unlike feline embryos, human embryos, by their genetic constitution, possess the remote potentiality to later exercise the typically human activities. It follows that they are already persons essentially.     

Introduction: Law and Disobedience

This essay considers some major questions raised by civil and other forms of conscientious disobedience. What distinguishes that form of dissent? Can we recognise the legitimacy of a political system yet defy its laws? Is disobeying a democratic decision especially or entirely unacceptable, or can disobedience be an instrument of democracy? If a regime recognises rights, how should we regard disobedience that appeals to those rights in challenging the regime’s laws? How should reasons for obedience figure in our thinking about justified disobedience? The essay locates the contributions that make up this special issue of Res Publica within these debates about disobedience. It questions whether any general theory of justified disobedience can command agreement: the conditions that give rise to conscientious disobedience -- conflicting values and judgements -- seem to preclude consensus on when its use is justified.     

Global Economy,Justice and Sustainability

Although this paper attends to some extent to the question whether the global economy promotes or impedes either justice or sustainability, its main focus is on the relationship between justice and sustainability. Whilst sustainability itself as a normative goal is about sustaining inter alia justice, justice itself requires intergenerationally the sustaining of the conditions of a good life for all. At the heart of this is a conception of justice as realising the basic rights of all–in contrast to a more demanding distributive principle or a less demanding principle of not violating the liberty rights or other basic rights of others. Although Pogge’s analysis that the global economy causes harm by failing to realise basic rights is seen as a useful challenge to common libertarian assumptions, the acceptance of other positive correlative duties, following Shue, is advocated. Insofar as the global economy fails to realise basic justice, the question is ‘how far can it realistically be changed?’ and this is a function partly of the moral attitudes of individuals at large.     

Variational solution of the one-dimensional t–J model

A new variational scheme based on a modified Bethe–Peierls method is used to study the ground state properties of the one-dimensional t–J model. Expectation values are evaluated by cutting out a four-site cluster from a correlated Fermi sea, the ground state of which is described by a variational trial wave function. We study a generalized Gutzwiller state where nearest-neighbour hole–hole correlations are controlled variationally. From the electron concentration dependence of the ground state energy, we determine the true thermodynamic boundary where segregation into an electron-rich, and purely hole phase sets in. We also determine the spinodal line and pair susceptibilities. The variational method is applied also to an extended t–J–V model, where V is the coupling constant of the charge interaction term.     

Updating mental models in predictive reasoning

Abstract

A mental model account for predictive judgement is proposed. According to this view, solving a predictive task involves the foundation ad updating of a mental he work as the relevant data are provided. The final model state determines the subject's predictive outcome. Two experiments examine the temporal course of reasoning in novices (Experiment 1) and experts (Experiment 2). Each task provided in succession a quantitative source (e.g. “Last year, of the vehidts that stopped at the cafe, 80% were cars and 20% were trucks”), a diagnostic source (e.g. “This vehide is mksy”) and a categorical choice (e.g. “What kind of vehicle was it?”). Two factors were manipulated: The order of sources aimed at analysing the contextual dependence of the updating processes, and the between-sources congruence (congruent or incongruent) in order to explore the integrative processes in model building. The pattern of the sources reading times, the choice times and the categorical choices suggested that: (1) the processing of a source depends on the previous one, (2) subjects try to integrste both sources into a single mental framework, and (3) experts and novices have a similar performance, although experts give more importance to the quantitative source in the diagnostic-quantitative order. These results are better accounted for by the mental model framework than both the heuristic and the formal view of prediction.