Place learning in scopolamine-treated rats: the roles of distal cues and catecholaminergic mediation

Experiments 1 and 2 tested the hypothesis that cholinergic receptor antagonists impair place learning in a water maze by interfering with the processing of distal, visual cues. Extramaze cues were offered to rats in the form of geometrical patterns arranged on the inner circumference of a curtain surrounding the water maze. In Experiment 1 the animals were offered both the distal cues and proximal cues in the form of pingpong balls in fixed positions on the surface of the water while only distal cues were present in Experiment 2. Animals were injected with either scopolamine (0.5 mg/kg body wt) or saline 20 min prior to the daily place learning sessions. Upon reaching criterion level performance the animals were tested on "rotation" sessions on which the distal cues were displaced. The outcome of such "rotations" demonstrated that-regardless of the presence or absence of proximal cues-scopolamine-treated rats relied at least as much as normal animals on the distal cues. The acquisition phase of both Experiments 1 and 2 demonstrated an almost complete lack of scopolamine-associated impairment in acquisition and performance of the place learning task. In Experiment 3 (when scopolamine was no longer administered) the subjects of Experiment 2 were exposed to a series of pharmacological "challenges" of their place learning performance and eventually to surgical ablation of the anteromedial prefrontal cortex. The outcome of the pharmacological challenges and the postoperative test of task performance demonstrated that the place learning performance of animals which had acquired the task under scopolamine was mediated by a neural substrate dissimilar to the substrate of task performance in normal animals. Rats acquiring the task while deprived of the cholinergic system demonstrated above-normal contributions to task mediation from catecholaminergic-probably dopaminergic-mechanisms and tentative results pointed to a "shift" toward prefrontal task mediation.     

Higher and Lower Pleasures – Doubts on Justification

According to the discontinuity view we can have a (lower) pleasure which, no matter how often a certain unit of it is added to itself, cannot become greater in value than a unit of another (higher) pleasure. All recent adherents of this view seem to rely basically on the same sort of reasoning which is referred to here as the preference test. This article presents three arguments, each of which indicates that the inference from the preference test to the discontinuity view is not conclusive.     

Effects of a Danish Student‐Centered Prosocial Intervention Program Among Japanese Children

Japan and Denmark represent two different educational cultures. Where Danish students in general report high scores on self‐esteem, Japanese children report low. A student‐centered and interaction‐based prosocial intervention program that was designed according to Danish educational culture was administered to children aged 11–12 years in Japan. Questionnaires measuring the children's quality of life (QoL) and metacognitive awareness were applied. Overall, the results showed that the student‐centered intervention improved the emotional well‐being aspect of QoL among Japanese boys. In contrast, Japanese boys’ scores on the declarative knowledge of metacognitive regulation declined. The teachers’ attitudes towards the intervention program were analyzed by use of interviews. The effect of the student‐centered intervention program is discussed with respect to the educational cultures in Japan.     

Neuroscience and Criminal Justice: Introduction

This special issue of The Journal of Ethics is devoted to ethical considerations of the use of neuroscience in the criminal justice system. In this introduction, an overview is provided of the different topics dealt with in the volume.     

Virtue Epistemology and Epistemic Twin Earth

A popular form of virtue epistemology—defended by such figures as Ernest Sosa, Linda Zagzebski and John Greco—holds that knowledge can be exclusively understood in virtue‐theoretic terms. In particular, it holds that there isn't any need for an additional epistemic condition to deal with the problem posed by knowledge‐undermining epistemic luck. It is argued that the sustainability of such a proposal is called into question by the possibility of epistemic twin earth cases. In particular, it is argued that such cases demonstrate the need for virtue‐theoretic accounts of knowledge to appeal to an independent epistemic condition which excludes knowledge‐undermining epistemic luck.     

Experimenting with phenomenology

We review the use of introspective and phenomenological methods in experimental settings. We distinguish different senses of introspection, and further distinguish phenomenological method from introspectionist approaches. Two ways of using phenomenology in experimental procedures are identified: first, the neurophenomenological method, proposed by Varela, involves the training of experimental subjects. This approach has been directly and productively incorporated into the protocol of experiments on perception. A second approach may have wider application and does not involve training experimental subjects in phenomenological method. It requires front-loading phenomenological insights into experimental design. A number of experiments employing this approach are reviewed. We conclude with a discussion of the implications for both the cognitive sciences and phenomenology.     

The epistemology of absence-based inference

Our main aim in this paper is to contribute towards a better understanding of the epistemology of absence-based inferences. Many absence-based inferences are classified as fallacies. There are exceptions, however. We investigate what features make absence-based inferences epistemically good or reliable. In Section 2 we present Sanford Goldberg’s account of the reliability of absence-based inference, introducing the central notion of epistemic coverage. In Section 3 we approach the idea of epistemic coverage through a comparison of alethic and evidential principles. The Equivalence Schema–a well-known alethic principle–says that it is true that $p$ if and only if $p$ . We take epistemic coverage to underwrite a suitably qualified evidential analogue of the Equivalence Schema: for a high proportion of values of $p$ , subject $S$ has evidence that $p$ due to her reliance on source $S^{*}$ if and only if $p$ . We show how this evidential version of the Equivalence Schema suffices for the reliability of certain absence-based inferences. Section 4 is dedicated to exploring consequences of the Evidential Equivalence Schema. The slogan ‘absence of evidence is evidence of absence’ has received a lot of bad press. More elaborately, what has received a lot of bad press is something like the following idea: absence of evidence sufficiently good to justify belief in $p$ is evidence sufficiently good to justify belief in $\sim p$ . A striking consequence of the Evidential Equivalence Schema is that absence of evidence sufficiently good to justify belief in p is evidence sufficiently good to justify belief in $\sim p$ . We establish this claim in Section 4 and show how this supports the reliability of an additional type of absence-based inference. Section 4 immediately raises the following question: how can we make philosophically good sense of the idea that absence of evidence is evidence of absence? We address this question in Section 5. Section 6 contains some summary remarks.     

Extended Cognition and Propositional Memory

The philosophical case for extended cognition is often made with reference to ‘extended‐memory cases’ (e.g. Clark & Chalmers 1998); though, unfortunately, proponents of the hypothesis of extended cognition (HEC) as well as their adversaries have failed to appreciate the kinds of epistemological problems extended‐memory cases pose for mainstream thinking in the epistemology of memory. It is time to give these problems a closer look. Our plan is as follows: in §1, we argue that an epistemological theory remains compatible with HEC only if its epistemic assessments do not violate what we call ‘the epistemic parity principle’. In §2, we show how the constraint of respecting the epistemic parity principle stands in what appears to be a prima facie intractable tension with mainstream thinking about cases of propositional memory. We then outline and evaluate in §3 several lines of response.