Hippocampal synaptic plasticity during instrumental learning

present research examined the role of hippocampal NMDA-dependent synaptic potentiation on appetitive instrumental conditioning under a continuous reinforcement schedule. In the first experiment, low (.025 mg.kg) or moderate (.05 mg/kg) dosages of the NMDA receptor antagonist, MK801, failed to increase the number of training days required to reach acquisition criterion; number of training days required to reach criterion for extinction were also unaffected. In the second experiment, a higher dosage (.10 mg/kg) of MK801 or induction of long-term potentiation failed to alter the number of responses occurring during acquisition. These data suggest that hippocampal synaptic potentiation does not play a prominent role in instrumental learning with simple contingency conditions. It is suggested that hippocampal LTP reflects a perceptual process that contributes differentially to spatial cognition, classical and instrumental conditioning.     

Hippocampal synaptic plasticity during instrumental learning

present research examined the role of hippocampal NMDA-dependent synaptic potentiation on appetitive instrumental conditioning under a continuous reinforcement schedule. In the first experiment, low (.025 mg.kg) or moderate (.05 mg/kg) dosages of the NMDA receptor antagonist, MK801, failed to increase the number of training days required to reach acquisition criterion; number of training days required to reach criterion for extinction were also unaffected. In the second experiment, a higher dosage (.10 mg/kg) of MK801 or induction of long-term potentiation failed to alter the number of responses occurring during acquisition. These data suggest that hippocampal synaptic potentiation does not play a prominent role in instrumental learning with simple contingency conditions. It is suggested that hippocampal LTP reflects a perceptual process that contributes differentially to spatial cognition, classical and instrumental conditioning.     

THE CREDIBLE SHRINKING ROOM:

Abstract— Becoming a proficient symbol user is a universal developmental last in the first years of life, but delecting and mentally representing symbolic relations can be quite challenging for young children To test the extent to which symbolic reasoning per se is problematic, we compared the performance of 2-year-olds in symbolic and nonsymbolic versions of a search task. The children had to use their knowledge of the location of a toy hidden in a room to draw an inference about where to find a miniature toy in a scale model of the room (and vice versa) Children in the nonsymbolic condition believed a shrinking machine had caused the room to become the model They were much more successful than children in the symbolic condition, for whom the model served as a symbol of the room The symbol understanding and use.     

On the Nature of Embarrassabllity: Shyness, Social Evaluation, and Social Skill

In this study, the correlates of embarrassability, or chronic susceptibility to embarrassment, were examined. Competing theoretical models suggest either that embarrassable people should be especially concerned about others' evaluations of them or that they should lack social skills. Further, shyness and embarrassment are typically considered to be closely related states. To test these propositions, 310 participants provided extensive self-reports of social skill, fear of negative evaluation, self-esteem, self-consciousness, and negative affectivity. Regression and factor analyses indicated that, compared to those of low embarrassability, highly embarrassable people are particularly concerned with the normative appropriateness of behavior and are more motivated to avoid rejection from others. In contrast, shyness was best predicted by low social self-confidence and low social skill. The data best support a social-evaluation model of embarrassment and argue that embarrassability is linked to the appropriateness of social behavior, and shyness to its effectiveness.     

Are All Hostility Scales Alike? Factor Structure and Covariation Among Measures of Hostility1

Few studies have examined the correlational and structural relationships between measures of hostility that may predict coronary heart disease. Using data from a population-based study (N= 2,682), we examined the factor structure among the five subscales from Siegel's (1986) Multi-dimensional Anger Inventory, the three subscales from Spielberger et al.'s (1985) anger expression scales, a Cook-Medley (Cook & Madley, 1954) hostility subscale that measures cynicism, and items measuring hostility from four scales that assess Type A behavior. Eight separate factors were identified: hostile anger expression, perceived control over the expression of one's anger, frequency of anger, ease of anger provocation, brooding, hostile outlook, cynicism, and sullenness. These results suggest that the structure of hostility measures is more complex than previous factor analyses have suggested. Our findings point to the dangers in assuming that a factor structure can be generalized beyond the data on which it is based to provide theoretical statements about psychological structure. The new scales appear to be valid because they correlate with demographic variables and indicators of social support in the expected directions.     

Behavioral Intentions: Which Ones Predict Fertility Behavior in Married Couples?1

The published literature on the relationship between behavioral intentions and fertility behavior exhibits four major problems: inconsistent and confusing use of theoretical constructs, limited use of different types of intentions, use of nonbehavioral outcomes, and failure to explore adequately the couple aspects of the intentions/behavior relationship. The study reported here addresses these problems by using a theoretical framework that characterizes the psychological/behavioral sequence leading to a planned conception, three different types of fertility intentions, a behavioral outcome variable, and data from 196 married couples with no children and 185 married couples with one child. Data analysis results in a simultaneous equation, constrained regression model which indicates that child-timing intentions are the most important predictors of proceptive behavior over a 3-1/2 year period and that childbearing intentions are next in importance; that behavioral intentions are the final common pathway through which fertility motivations, attitudes, beliefs, and desires affect behavior; that the use of proceptive behavior as an outcome variable improves the explanatory power of our models; and that the interaction of couple intentions do not demonstrate greater husband or wife influence over couple proceptive behavior but do demonstrate that disagreement has a delaying effect on the onset of that behavior.     

Discursive logic towards a logic of rational discourse

Both logic and philosophy of science investigate formal aspects of scientific discourse, i.e. properties of (non-monotonic) consequence operations for discursive logic. In the present paper we handle two of them: paraconsistency and enthymematycity.Supported by grants from the Alexander von Humboldt-Stiftung, form the Fulbright-Foundation and from the Center for Philosophy of Science at the University of Pittsburgh.Presented byJan Zygmunt     

Taking an individualized approach to the assessment of self-efficacy and the prediction of alcoholic relapse

The present study reports on a clinical instrument designed for assessing self-efficacy in alcoholics. In contrast to studies that construct general measures, it was proposed that taking an individualized approach to assessment might offer an effective methodology. Thirty-four alcoholics in an outpatient, behaviorally oriented treatment program participated as subjects. During therapy, an Individualized Self-Efficacy Survey (ISS) was developed for each subject. The ISS was developed by (a) administering the Drinking Patterns Questionnaire (DPQ) to identify important problem areas (e.g., work, children, marital) and specific drinking antecedents and (b) constructing a 15-item scale using each drinker's most important cues. The utility of having clients choose their own items was supported by finding a significant relationship between problem areas identified as important on the DPQ and the areas reported as surrounding relapse. ISS ratings were reflective of efficacy changes during treatment, while posttreatment ISS scores were predictive of subsequent relapse. Situation-specific prediction of relapse was not found. The advantages of this methodology for clinical use are discussed, while general directions for future research are suggested.