Plasticity associated with escalated operant ethanol self-administration during acute withdrawal in ethanol-dependent rats requires intact matrix metalloproteinase systems

Repeated cycles of ethanol intoxication and withdrawal associated with dependence induce neuroadaptations in a variety of brain systems. Withdrawal-induced negative emotional states can be ameliorated by ethanol consumption; a learned process termed negative reinforcement. Accordingly, a dependence-induced phenotype is escalated ethanol self-administration. Matrix metalloproteinases (MMPs) are proteolytic enzymes which degrade the extracellular matrix to allow for synaptic reorganization and plasticity. To test the hypothesis that an intact MMP system is required for animals to learn about the negative reinforcing effects of ethanol and display escalated self-administration during acute withdrawal when ethanol-dependent, male Wistar rats were trained to self-administer ethanol and then assigned to either acute or chronic MMP inhibition treatment groups. The chronic treatment group received intracerebroventricular (ICV) infusions of the broad spectrum MMP inhibitor FN-439 or artificial cerebrospinal fluid (aCSF) via osmotic minipumps during a 1 month ethanol dependence induction period and subsequent post-dependence induction self-administration sessions that occurred during acute withdrawal. The acute treatment group only received ICV FN-439 or aCSF on the day of self-administration sessions following dependence induction during acute withdrawal. The results showed that inhibition of MMPs attenuated escalated ethanol self-administration following chronic and acute exposure conditions. Furthermore, once learning (i.e., plasticity) had occurred, MMP inhibition had no impact on escalated response patterns and animals previously subjected to MMP inhibition that did not escalate evidenced normal escalations in operant ethanol self-administration once FN-439 treatments were terminated. Thus, the present data identified that an intact MMP system is required for the escalated responding that occurs during acute withdrawal in dependent animals and implicate such escalation as a learned response.     

Dimensions of Perfectionism, Unconditional Self-Acceptance, and Depression

The current research investigated the associations among dimensions of perfectionism, unconditional self-acceptance, and self-reported depression. A sample of 94 students completed the Multidimensional Perfectionism Scale, the Unconditional Self-Acceptance Questionnaire, and a self-report depression measure. Correlational results indicated that all three trait dimensions of perfectionism (i.e., self-oriented, other-oriented, and socially prescribed perfectionism) were associated negatively with unconditional self-acceptance. Also, as expected, depression was associated with relatively low unconditional self-acceptance. Finally, a path analysis revealed that unconditional self-acceptance mediated the association between socially prescribed perfectionism and depression, and other-oriented perfectionism was found to affect depression only indirectly through its association with low levels of self-acceptance. The findings indicate that perfectionists evaluate themselves in terms of a contingent sense of self-worth, and as such, they are vulnerable to psychological distress when they experience negative events that do not affirm their self-worth.     

Uncertainty orientation in the group context: categorization effects on persuasive message processing

Persuasive messages often originate from in-group or out-group sources. Theoretically, in-group categories could facilitate heuristic-based message processing (because of the attractiveness of in-groups and their social reality cues) or systematic-based processing (because of high personal relevance of the message). The authors expected individual differences in uncertainty orientation and socially based expectancy congruence to be important variables in understanding these processes. Participants were exposed to strong or weak, in-group or out-group messages that were either expectancy congruent (in-group agreement, out-group disagreement) or expectancy incongruent (in-group disagreement, out-group agreement). As predicted, uncertainty-oriented participants increased systematic information processing under incongruent conditions relative to congruent (i.e., relatively certain) conditions; certainty-oriented individuals processed systematically only under congruent conditions. These findings suggest that uncertainty that has been created through social-categorization conflicts is treated differently by people of different personality styles.     

Abstract-concept learning and list-memory processing by capuchin and rhesus monkeys

Three capuchin monkeys (Cebus apella) touched the lower of 2 pictures (same) or a white rectangle (different), increased same/different abstract-concept learning (52% to 87%) with set-size increases (8 to 128 pictures), and were better than 3 rhesus monkeys (Macaca mulatta). Three other rhesus that touched the top picture before choices learned similar to capuchins but were better at list-memory learning. Both species' serial position functions were similar in shape and changes with retention delays. Other species showed qualitatively similar shape changes but quantitatively different time-course changes. In abstract-concept learning, qualitative similarity was shown by complete concept learning, whereas a quantitative difference would have been a set-size slope difference. Qualitative similarity is discussed in relation to general-process versus modular cognitive accounts.     

First-trial adaptation to prism exposure

Terminal target-pointing error on the 1st trial of exposure to optical displacement is usually less than that expected from the optical displacement magnitude. Such 1st trial adaptation was confirmed in 2 experiments (N = 48 students in each) comparing pointing toward optically displaced targets and toward equivalent physically displaced targets (no optical displacement), with visual feedback delayed until movement completion. First-trial performance could not be explained by ordinary target undershoot, online correction, or reverse optic flow information about true target position and was unrelated to realignment aftereffects. Such adaptation might be an artifact of the asymmetry of the structured visual field produced by optical displacement, which induces a felt head rotation opposite to the direction of the displacement, thereby reducing the effective optical displacement.     

Piaget's Grouping II: The model, its assessment, and the effects of training

Although Piaget emphasized the importance of negation in equilibration theory, few data are available pertaining to children's use of Grouping II (Gr. II) logic, which relies on negation. Three approaches to assessing Gr. II capability are reviewed in light of Piaget's (1949, Traité de logique: Essai de logistique opératoire, Paris: Colin) discussion of Gr. II. The paper describes a new task to assess three aspects of Gr. II thought: (a) naming secondary classes, (b) comparing a secondary class with a primary class contained within it, and (c) reasoning about vicariance relationships. An experimental group of third graders trained to use Gr. II logic performed significantly better on post-test tasks than did an untrained control group. Training included rule instruction, evaluative and informative feedback, and manipulative activities.