Rats know when they remember: transfer of metacognitive responding across odor-based delayed match-to-sample tests

Metamemory entails cognitively assessing the strength of one’s memories. We tested the ability of nine Long-Evans rats to distinguish between remembering and forgetting by presenting a decline option that allowed a four-choice odor-based delayed match to sample (DMTS) tests to be by-passed. Rats performed significantly better on tests they chose to take than on tests they were forced to take, indicating metacognitive responding. However, rather than control by internal mnemonic cues, one alternative explanation is that decline use is based on external test-specific cues that become associated with increased rewards overtime. To examine this possibility, we tested rats on three generalization tests in which external contingencies were inconsistent and therefore could not serve as discriminative cues. Rats transferred adaptive use of the decline response in tests that eliminated memory by presenting no sample, increased memory by presenting multiple samples, and both weakened and strengthened memory by varying the retention interval. Further, subjects chose to take or decline the test before encountering the memory test, providing evidence that rats based their metacognitive responding on internal cues rather than external ones. To our knowledge, this is the first robust evidence for metamemory in rats using the DMTS decline-test paradigm in which several possible sources of external stimulus control can be ruled out.     

Self-denial and the role of intentions in the attribution of agency

The ability to distinguish between our own actions and those of an external agent is a fundamental component of normal human social interaction. Both low- and high-level mechanisms are thought to contribute to the sense of movement agency, but the contribution of each is yet to be fully understood. By applying small and incremental perturbations to realistic visual feedback of the limb, the influence of high-level action intentions and low-level motor predictive mechanisms were dissociated in two experiments. In the first, participants were induced to claim agency over movements that were subject to large perturbations and to deny agency over self-produced unperturbed movements despite the application of motor corrections by low-level mechanisms. A control experiment confirmed that if reaches met with their intended goal then they were more likely to be attributed to the agent, regardless of the discrepancy between the actual and seen positions of the limb.     

Attentional inhibition mediates inattentional blindness

Salient stimuli presented at unattended locations are not always perceived, a phenomenon termed inattentional blindness. We hypothesized that inattentional blindness may be mediated by attentional inhibition. It has been shown that attentional inhibition effects are maximal near an attended location. If our hypothesis is correct, inattentional blindness effects should similarly be maximal near an attended location. During central fixation, participants viewed rapidly presented colored digits at a peripheral location. An unexpected black circle (the critical stimulus) was concurrently presented. Participants were instructed to maintain central fixation and name each color/digit, requiring focused attention to that location. For each participant, the critical stimulus was presented either near to or far from the attended location (at the same eccentricity). In support of our hypothesis, inattentional blindness effects were maximal near the attended location, but only at intermediate task accuracy.     

The Novelty of Nano and the Regulatory Challenge of Newness

A great deal has been made of the question of whether nano-materials provide a unique set of ethical challenges. Equally important is the question of whether they provide a unique set of regulatory challenges. In the last 18 months, the US Environmental Protection Agency has begun the process of trying to meet the regulatory challenge of nano using the Toxic Substances Control Act (1976)(TSCA). In this central piece of legislation, ‘newness’ is a critical concept. Current EPA policy, we argue, does not adequately (or ethically) deal with the novelty of nano. This paper is an exploration of how to do a better job of accounting for nanomaterials as ‘new.’ We explore three alternative ways that nanomaterials might be made to fall under the TSCA regulatory umbrella. Since nanomaterials are of interest precisely because of the exciting new properties that emerge at the nano-scale, each of these three alternatives must meet what we call the ‘novelty condition’ and avoid what we call the ‘central paradox’ of existing regulatory policy. Failure to meet either of these conditions is a moral failure. We examine both the strengths and weaknesses of each alternative in order to illuminate the conceptual, practical, and moral challenges of novelty.     

Randomized Trial Comparing Two Treatment Strategies Using Prize-Based Reinforcement of Abstinence in Cocaine and Opiate Users

We compared two strategies of prize-based contingency management (CM) in methadone-maintained outpatients. Urine was tested thrice weekly for 5 weeks pre-CM, 12 weeks CM, and 8 weeks post-CM. Participants were randomly assigned to a cocaine contingency (four prize draws for each cocaine-negative urine, N  =  29) or an opiate-cocaine contingency (one draw for each urine negative for opiates or cocaine, four draws if negative for both, N  =  38). There were no group differences in cocaine abstinence during CM or post-CM and no differences in opiate abstinence during CM. Opiate abstinence was greater in the opiate-cocaine group post-CM, and heroin craving was reduced in this group during and post-CM. Draws earned per cocaine-negative urine (four vs. one) did not affect cocaine use.     

How well can the theory of planned behavior account for occupational intentions?

We tested the capacity of an extended version of the theory of planned behavior (TPB) to account for intentions to work for the UK’s National Health Service (NHS) as a nurse, physiotherapist or radiographer amongst three groups: professionally unqualified (N = 507), in professional training (N = 244), and professionally qualified (N = 227). We found strong support for the three core TPB variables attitude, subjective norm and perceived behavioral control as predictors of behavioral intention, and limited support for two additional variables: moral obligation and identification. There were some differences in the relative importance of TPB variables between groups. We conclude that the TPB has utility for more complex behaviors as well as simpler ones that are more frequently researched. However, more attention should be paid to differences in people’s circumstances, particularly regarding past vocational decisions and behavior, and to obstacles to implementing an intention.     

Some Antiepileptic Compounds Impair Learning by Rats in a Morris Water Maze

In the present experiments, we investigated the effects of several commonly employed antiepileptic drugs on the performance of adult rats in a Morris water maze task. We found that phenytoin treatment produced the most deleterious performance impairments across all days of training, and that these performance deficits are not likely due to any general sensorimotor impairments. Carbamazepine had milder, but detectable negative effects, as carbamazepine-treated animals exhibited initial acquisition deficits, but rapidly achieved escape levels comparable to controls. In marked contrast, valproate and ethosuximide had no detectable effects on learning in the water maze. These results parallel previous findings in rats treated with these compounds and tested in an instrumental learning task, and are in general agreement with the human clinical literature. To the extent that one might wish to minimize learning deficits associated with maintenance on antiepileptic drugs, phenytoin is definitely not the treatment of choice, while valproate or ethosuximide are apparently much less disruptive.     

Prolegomena to any Future History of Analytic Philosophy

Abstract: The careful historical and metaphilosophical attention recently bestowed upon analytic philosophy has revealed that traditional ways of defining it are inadequate. In the face of this inadequacy, contemporary authors have proposed new definitions that detach analytic philosophy from its turn of the twentieth century origins. I argue that this contemporary trend in defining analytic philosophy is misguided, and that it diminishes the likelihood of our coming to an accurate historical and metaphilosophical understanding of it. This is especially unsatisfactory since such understanding is essential to finding an adequate remedy for the widely perceived ills of contemporary analytic philosophy. I suggest that a more fruitful approach to developing such understanding might begin with treating the unity of analytic philosophy as illusory.     

The simultaneous consideration of between‐participants and within‐participants analyses in research on predictors of behaviours: The issue of dependence

Although there is wide acceptance among personality and social psychologists of the importance of performing both between‐participants and within‐participants analyses to obtain a more complete picture of the phenomena under investigation, such analyses are rare (Mishela, 1990). Research on the predictors of behaviour, particularly concerning variables such as attitude, subjective norm, affect, cognition, and intention provides an exception, where the results from within‐participants analyses are sometimes compared to the results from between‐participants analyses. These comparisons raise the issue of whether the two types of analyses are independent of each other (and whether they can be validly compared), which is the topic of the present paper. Although we show that there is dependence, which suggests that it is a bad idea to compare both kinds of analyses, we also show that the degree of dependence approaches zero as the number of participants and items increase. Thus, with a sufficiently large design, the degree of dependence is unimportant, and therefore is no obstacle to the simultaneous consideration of both within‐participants and between‐participants analyses. How large is large enough? A set of computer simulations suggests that 15 participants and 15 items is sufficient, though we provide data from which researchers can designate their own criteria. Copyright © 2004 John Wiley & Sons, Ltd.