The effects of binge MDMA on acquisition and reversal learning in a radial-arm maze task

The current study used the partially-baited radial-arm maze paradigm to study the effects of a single-treatment high-dose exposure ('binge') to MDMA (± 3,4-methylenedioxymethaphemtamine or 'Ecstasy') on memory task acquisition. Sprague-Dawley rats were administered a binge dose (4 × 10 mg/kg) of MDMA and their ability to subsequently acquire the radial-arm maze task was compared against saline controls. The MDMA-treated rats were significantly slower to learn the task and made more reference memory errors than the controls. Working memory function was found to be relatively unimpaired. Following a reversal of task rules the MDMA-treated rats were again significantly slower to acquire the appropriate rule despite having eventually achieved a similar level of overall performance as control rats. However evidence of drug tolerance was found when all rats were challenged with an acute low dose of MDMA (1 × 4.0 mg/kg) because the binge MDMA rats were relatively less impaired. Therefore, although binge treated MDMA rats were able to achieve very accurate performance equivalent to the controls they took significantly longer to do this and were less able to adapt their behavior to a change in task rules. In addition the binge treated MDMA rats displayed tolerance to acute MDMA exposure. These findings are consistent with the possibility that human Ecstasy users may show deficits in acquiring information and may experience deficits in cognitive flexibility as well as developing tolerance to the drug with repeated exposure.     

The empirical case for role-governed categories

Most theories of categorization posit feature-based representations. Markman and Stilwell (2001) argued that many natural categories name roles in relational systems and therefore they are role-governed categories. There is little extant empirical evidence to support the existence of role-governed categories. Three experiments examine predictions for ways that role-governed categories should differ from feature-based categories. Experiment 1 shows that our knowledge of role-governed categories, in contrast to feature-based categories, is largely about properties extrinsic to category members. Experiment 2 shows that role-governed categories have more prominent ideals than feature-based categories. Experiment 3 demonstrates that novel role-governed categories are licensed by the instantiation of novel relational structures. We then discuss broader implications for the study of categories and concepts.     

Do wild New Caledonian crows (<Emphasis Type="Italic">Corvus moneduloides</Emphasis>) attend to the functional properties of their tools?

New Caledonian crows are the most proficient non-hominin tool manufacturers but the cognition behind their remarkable skills remains largely unknown. Here we investigate if they attend to the functional properties of the tools that they routinely use in the wild. Pandanus tools have natural barbs along one edge that enable them to function as hooking implements when the barbs face backwards from the working tip. In experiment 1 we presented eight crows with either a non-functional (‘upside-down’) or a functional pandanus tool in a baited hole. Four of the crows never flipped the tools. The behaviour of the four flipping birds suggested that they had a strategy of flipping a tool when it was not working. Observations of two of the eight crows picking up pandanus tools at feeding tables in the wild supported the lack of attention to barb direction. In experiment 2 we gave six of the eight crows a choice of either a barbed or a barbless pandanus tool. Five of the crows chose tools at random, which further supported the findings in experiment 1 that the crows paid little or no attention to the barbs. In contrast, a third experiment found that seven out of eight crows flipped non-functional stick tools significantly more than functional ones. Our findings indicate that the crows do not consistently attend to the presence or orientation of barbs on pandanus tools. Successful pandanus tool use in the wild seems to rely on behavioural strategies formed through associative learning, including procedural knowledge about the sequence of operations required to make a successful pandanus tool. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Learning from experience: Examining the impact of client work upon two trainee therapists

This qualitative research study, focusing on the learning and change of two trainee therapists over a nine‐month period, was conducted by the trainees themselves. In collecting and analysing their data, the researchers made use of the heuristic methodology, to which some of the principles of the co‐operative inquiry methodology were added. The findings shed light on some of the ways in which trainee counsellors and psychotherapists might learn through their work with clients, the forms and contexts in which this learning may arise, and how the learning might affect the trainees. The findings additionally highlight some of the possible benefits of engaging in research for trainee counsellors and psychotherapists, in terms of their roles as practitioners. These include positive changes in the ways in which they work with clients, and changes in the ways they think about their practice.     

Zur Dynamik der Interaktion in der Supervision

The manifold functions of a supervisor in following the course of complex processes together with the trainee, are: ? to keep the goals of the supervision in view, ? to establish a teaching alliance and to support the wish and ambitions of the candidate to learn, ? to build a platform for the complex interactions with the trainee with regard to the dynamics of the training situation and keeping in mind the institutional influences, ? to lay down the setting for the work, ? to explore and to reflect how transference and counter-transference influence the interaction between patient and analyst as well as between trainee and supervisor, ? to examine these interactions together focussing continuously on the interaction between candidate and patient, and to encourage the candidate to do the same on his own, ? to continuously formulate hypotheses about the core conflict, the transference phenomena and resistance of the patient, ? to explore and reflect on the cooperative work.     

Expectancy Disconfirmation and Negotiator Reactions Across Negotiation Episodes

In the negotiation literature, relatively little attention has been paid to the impact of negotiator goals and expectancy disconfirmations on negotiator behaviors and affective outcomes. We found that negotiators with larger negative expectancy disconfirmations were less satisfied; set lower targets for a subsequent negotiation; and were more likely to settle with the other party in the second negotiation, rather than requiring third-party imposition of a settlement. Those negotiators who settled had more positive feelings and perceptions about the negotiation and set higher targets for a third negotiation. Further, negotiators who experienced repeated high levels of negative expectancy disconfirmation also experienced the greatest decrements in their feelings and perceptions across negotiation episodes. Implications of study findings for future research are discussed.     

Considerations Relating to the Study of Group Differences in Intelligence

ABSTRACT— There are signs that the debate over racial and gender differences in intelligence is about to begin again. In this article we will be concerned primarily with racial differences but will make remarks about gender differences where applicable. Previously there have been bitter arguments over whether or not races exist, over whether it is either important or proper to study racial and gender differences in intelligence, and over the conclusions that have been drawn about environmental and genetic causes as determinants of these differences. We argue that races do, indeed, exist and that studying differences in cognitive competence between groups is a reasonable thing to do. We also point out that past research on both racial and gender differences in intelligence has been marked by methodological errors and overgeneralizations by researchers on all sides of the issue. We propose ten principles of design, analysis, and reporting that ought to be considered carefully when doing or evaluating research in this area.