Dopamine D2 receptors mediate reversal learning in male C57BL/6J mice

Dopamine is critical for directing goal-oriented behavior. We investigated dopamine D₂ receptor involvement in reversal learning and reinforcement efficacy in mice lacking functional dopamine D₂ receptors and their heterozygous and wild-type littermates. Mice discriminated between two odors to receive a food reinforcer: One odor signaled a reinforcer (S⁺); the other odor signaled no reinforcer (S⁻). After mice learned the S⁺/S⁻ relationship, we inverted the reinforcement contingencies. The necessary number of trials to relearn the new reinforcement contingencies served as our index of reversal learning. Mice lacking functional dopamine D₂ receptors repeatedly failed to inhibit previously reinforced responses during reversal trials. In a separate experiment, mice responded for reinforcers on a progressive ratio schedule of reinforcement. Mice lacking functional dopamine D₂ receptors earned significantly fewer reinforcers than did heterozygous mice. Our results suggest that dopamine D₂ receptors regulate reversal learning and influence the reinforcing efficacy of natural rewards.     

Considering rational self-interest as a disposition: organizational implications of other orientation

In contrast with major theories of attitudes and behavior, the authors propose that individuals are not equally motivated to pursue their self-interests. The authors show that differences in other orientation affect the extent to which actions and attitudes reflect self-interested calculation (instrumental rationality) and the extent to which beliefs represent their external environment (epistemic rationality). These differences have consequences for processes underlying a wide range of attitudes and behavior typically assumed to be rationally self-interested. Thus, the authors' model exposes a common explanation for diverse organizational phenomena. It also clarifies inconsistencies surrounding the validity of certain attitudinal and motivational models, the relationship between job attitudes and actions, cross-cultural differences in attitudes and behavior, escalation of commitment, and the relationship between chief executive officer characteristics and organizational performance.     

Development of an ethanol model using social insects: III. Preferences for ethanol solutions

Experiments are designed to assess whether free-flying honey bees have an aversion to an ethanol solution when given a choice between targets containing an ethanol solution in sucrose or sucrose only. Animals given a choice between a 1% ethanol solution and sucrose only show no aversion to the ethanol solution either in acquisition or extinction. Honey bees given a choice between a 5% ethanol solution and sucrose only show no differences in the initial choice of targets but some ees do switch over to the sucrose-only target. Performance during extinction indicates that bees landed on the previously reinforced sucrose-only target more than the target previously containing the 5% ethanol solution. An experiment in which bees were given a single 5%, ethanol target showed that of 20 bees, 11 returned for the entire 12 trials of the experiment. All bees returned at least 6 times to the 5% ethanol target. Additional experiments were run on harnessed foragers in a palatability study of alcoholic beverages consumed by humans. The results of the palatability experiment indicate that in general, bees prefer more sweet drinks with less alcohol.     

Stressors and child and adolescent psychopathology: moving from markers to mechanisms of risk

In the first half of this review, the authors critically evaluate existing research on the association between stressors and symptoms of psychopathology in children and adolescents. This analysis reveals (a) problems with conceptualizations of stress, (b) variability in measurement of stressors, and (c) lack of theory-driven research. To address these problems, the authors propose a general conceptual model of the relation between stressors and child and adolescent psychopathology. The authors examine basic tenets of this general model in the second half of this article by testing a specific model in which negative parenting mediates the relation between economic stressors and psychological symptoms in young people. Results generally provide support for the specific model as well as for the broader model.     

The acquisition of category structure in unsupervised learning

Four experiments examined the extent to which prior knowledge influences the acquisition of category structure in unsupervised learning conditions. Prior knowledge is general knowledge about a broad domain that explains why an object has the features it does. Category structure refers to the statistical regularities of features within and across categories. Subjects viewed items and then divided them up into the categories that seemed most natural. Each item had one feature that was related to prior knowledge and five features that were not. The results showed that even this small amount of prior knowledge helped subjects to discover the category structure. In addition, prior knowledge enhanced the learning of many of the category's features, and not just the features that were directly relevant to the knowledge. The results suggest that prior knowledge may help to integrate the features of a category, thereby improving the acquisition of category structure.     

An application of the state-trait concept to the need for achievement

This study concerned relationships between state (situationally defined) n Ach, trait n Ach, and sex of subject in 80 college freshmen. Three standard n Ach tests (the Adjective Check List, Personal Preference Schedule, and TAT measures) and the mean of n Ach states measured under nonarousal conditions were used as trait measures. State measures of n Ach were also obtained in four experimental conditions (Social Ability, Success-Failure, Conventional Arousal, and Extrinsic Competition). There were no significant correlations between the four trait measures. The mean of states in the neutral conditions was highly predictive of states in three of the four arousal conditions, but none of the standard trait tests predicted state arousal to any significant extent.     

MAINTENANCE OF FOREIGN LANGUAGE VOCABULARY AND THE SPACING EFFECT

Abstract— In a 9-year longitudinal investigation, 4 subjects learned and relearned 300 English-foreign language word pairs. Either 13 or 26 relearning sessions were administered at intervals of 14, 28, or 56 days. Retention was tested for 1, 2, 3, or 5 years after training terminated. The longer intersession intervals slowed down acquisition slightly, but this disadvantage during training was offset by substantially higher retention. Thirteen retraining sessions spaced at 56 days yielded retention comparable to 26 sessions spaced at 14 days. The retention benefit due to additional sessions was independent of the benefit due to spacing, and both variables facilitated retention of words regardless of difficulty level and of the consistency of retrieval during training. The benefits of spaced retrieval practice to long-term maintenance of access to academic knowledge areas are discussed.     

An examination of stimulus technology level and preference displacement during multiple stimulus without replacement preference assessments

Researchers have observed that preference for edible items may displace preference for leisure items when items from the stimulus classes are assessed together within multiple stimulus without replacement (MSWO) preference assessments. The current study extends previous research by examining patterns of preference and displacement when assessing preference for high-tech and low-tech leisure items. We conducted three separate MSWO preference assessments; one assessing low-tech items, another assessing high-tech items, and a combined assessment (using the top four high- and low-tech items from the previous assessments) to test for displacement. Preference for high-tech items fully or partially displaced preference for low-tech items in five of eight participants. We then conducted concurrent and single operant reinforcer assessments using the highly preferred high-tech and low-tech items. Reinforcer assessment results demonstrated similar levels of responding for the highest preferred high-tech and low-tech items, indicating that combining high- and low-tech items within preference assessments may influence the validity of results.     

Argumentation,Adversariality, and Social Norms

Janice Moulton's “The Adversary Method: A Philosophical Paradigm” articulated several criticisms of the popular idea of philosophy as adversarial debate. Moulton criticizes it on epistemic grounds, arguing that philosophy's overreliance on adversarial debate is to the detriment of its goals. Some, notably Trudy Govier, have argued in favor of at least a minimal adversariality, governed by norms of respectful argumentation. This paper suggests that Govier's faith in these norms is misplaced, because it neglects the social circumstances of the arguers. While some authors have argued that politeness and aggression apply differently to those of different genders, this paper extends that analysis to social identities other than gender. In fact, given certain assumptions about the philosophy of language, engagement in polite adversarial debate may not even be possible for people occupying certain social locations.     

Meaning before grammar: A review of ERP experiments on the neurodevelopmental origins of semantic processing

Psychonomic Bulletin & Review - According to traditional linguistic theories, the construction of complex meanings relies firmly on syntactic structure-building operations. Recently, however,...