Learned preferences induced by electrical stimulation of a food-related area of the parabrachial complex: effects of naloxone

Electrical stimulation of the External Lateral Parabrachial Subnucleus (LPBe), a food-related area, induced behavioral preferences for associated stimuli in a taste discrimination learning task. Although this stimulation appeared to be ineffective to elicit standard lever press self-stimulation, it induced place preference for one of two training compartments of a rectangular maze in which animals (adult male Wistar rats) received concurrent electrical brain stimulation. In subjects that consistently showed a preference behavior in different trials, administration of the opioid antagonist naloxone (4 mg/ml/kg) blocked concurrent learning when the test was made in a new maze but not in the same maze in which animals had learned the task. These results are discussed in terms of the possible participation of the LPBe subnucleus in different natural and artificial brain reward systems.     

Adaptation to sensory-motor temporal misalignment: instrumental or perceptual learning?

Sensory-motor delays vary over the course of development and under different environmental conditions. Previous research has shown that humans can compensate for the resulting temporal misalignment while performing sensory-motor tasks (e.g., Cunningham, Billock, & Tsou, 2001a), but remains silent on the question of whether perceptual learning-similar to that involved in adaptation to spatial misalignment (e.g., Redding & Wallace, 1993) and in adaptation to purely intersensory misalignment (e.g., Fujisaki, Shimojo, Kashino, & Nishida, 2004)-is also involved in this adaptive response. Following an attempted replication of Cunningham et al.'s (2001a) study in a preliminary experiment, we present in this paper two experiments that demonstrate that after-effects of adaptation to temporal misalignment do not spontaneously decay. The literature on adaptation to spatial misalignment suggests that, while instrumental learning spontaneously decays in the absence of reinforcement, perceptual learning persists. Therefore our results are consistent with adaptation being effected through perceptual learning.     

Signalling signalhood and the emergence of communication

A unique hallmark of human language is that it uses signals that are both learnt and symbolic. The emergence of such signals was therefore a defining event in human cognitive evolution, yet very little is known about how such a process occurs. Previous work provides some insights on how meaning can become attached to form, but a more foundational issue is presently unaddressed. How does a signal signal its own signalhood? That is, how do humans even know that communicative behaviour is indeed communicative in nature? We introduce an experimental game that has been designed to tackle this problem. We find that it is commonly resolved with a bootstrapping process, and that this process influences the final form of the communication system. Furthermore, sufficient common ground is observed to be integral to the recognition of signalhood, and the emergence of dialogue is observed to be the key step in the development of a system that can be employed to achieve shared goals.     

The theoretical and empirical links between bullying behavior and male sexual violence perpetration

Bullying experiences and male sexual violence (SV) perpetration are major public health problems, and while extant literature suggests that they may share some developmental correlates, there is no established empirical link between being a perpetrator or victim of bullying and SV perpetration in the literature. Nonetheless, some SV prevention programs in the U.S. include bullying prevention components for elementary and middle-school aged children. Research is needed to test the hypothesized links between bullying experiences and SV perpetration to determine whether bullying prevention programs are likely to prevent SV perpetration. The purpose of this paper is to present results from a review of research on each of these topics and to discuss the potential shared and unique risk and protective factors within a social-ecological framework. The paper concludes with suggested directions for future research.     

Necessity, possibility and belief: A study of syllogistic reasoning

The present study extended the investigation of the belief bias effect in syllogistic reasoning in two ways: (1) The effect was studied under instructions to decide whether conclusions were possible, as well as necessary, given the premises; and (2) the effect was studied for types of syllogism where people rarely endorse the conclusions as well as those (valid and fallacious) where endorsements are common. Three experiments are reported, which show first that there is a marked tendency to reject unbelievable conclusions relative to abstract or neutral controls on all kinds of syllogism and under both types of instruction. There was also significant evidence of positive belief bias (increased acceptance of believable conclusions) and of interactions between belief bias effects and logical form. The results are discussed with particular respect to accounts of belief bias offered by theorists in the mental-model tradition.     

Prenatal testosterone treatment potentiates the aggression‐inhibiting effect of the neurosteroid dehydroepiandrosterone in female mice

The neurosteroid dehydroepiandrosterone (DHEA) is a powerful inhibitor of aggression in murine models when given for 15 days and potentially may be useful in the management of inappropriate human aggression. Although the biosynthesis and metabolism of DHEA have been described, little is known about the potential effect of the steroidal environment during sexual differentiation on the subsequent response to DHEA. Whether prenatal androgen exposure influences the subsequent response to DHEA was assessed by comparing the effect of DHEA (80 μg/d) on aggression in female offspring where dams were treated with 1, 10, or 100 μg of testosterone (T) on days 15 to 18 of gestation (Experiment I) or that developed in different uterine positions (Experiment II). The results showed that DHEA decreased attack behavior in general and that the 100‐μg prenatal T treatments enhanced the antiaggressive effect of this neurosteroid. Neither the lower doses of exogenously administered T nor the uterine position led to an enhanced response to DHEA. In addition, whether DHEA produced changes in social and nonsocial activities was examined. In the 100‐μg T females, DHEA increased the duration of the former and decreased the frequency and duration of the latter, indicating that it was not a general decrement in behavioral expression that mediated the enhanced response to the antiaggressive effect of DHEA. In the second experiment, DHEA treatment led to increased frequencies of social nonaggressive and nonsocial activities. However, the uterine positions × treatment interactions were not significant, demonstrating that contiguity to male fetuses did not differentially affect the response to DHEA. Aggr. Behav. 27:130–138, 2001. © 2001 Wiley‐Liss, Inc.     

Innocence Without Naivete,Uprightness Without Stupidity: The Pedagogical Kavannah of Emmanuel Levinas

While it is impossible to transfigurephilosophical and Judaic thought of EmmanuelLevinas into a moral agenda for education orthe programmatic regularities of a pedagogicalmethodology, this paper argues for theimportance of his work for re-openingeducational questions. These questions engagethe problem of what it could mean to livehistorically, to live within an uprightattentiveness to traces of those who haveinhabited times and places other than one'sown. In this sense, I address the problem ofremembrance as a question of and for history,as a force of inhabitation, as an inheritance weare obligated to live within, that intertwineswith our sense of limits and possibilities,hopes and fears, identities and distinctions.Substantively, this problem is manifest in howone attends to the experiences of others: howone reads, how one views, and how one listens,always historically specific normalizedpractices that in any given epoch are ingrainedin what it means to live in consort withothers, to live as though the lives of otherpeople mattered. The paper seeks to display thefecundity of the thought of Levinas forre-thinking such issues.     

Epistemic Unities

I bring together social ontology and social epistemology by consideringsocial entities (``epistemic unities') that are constituted by the holdingof epistemic relations between their members. In particular, I focus onthe relation of taking someone as an expert. Among the types of structuresexamined are ones with a single expert and one or more non-experts whomay or may not know of each other's situation; and ones with more thanone expert, including cases in which the relation between the experts ishierarchical and cases in which it is symmetrical. These structures modela variety of social situations which can thus be given a unified treatment.Among the cases I discuss are persons, which I argue are multiple-expertunities of persons at times. Taking a person as a social unity like this offersa clear sense in which some groups can also be person-like.