Belief revision and uncertain reasoning

When a new piece of information contradicts a currently held belief, one has to modify the set of beliefs in order to restore its consistency. In the case where it is necessary to give up a belief, some of them are less likely to be abandoned than others. The concept of epistemic entrenchment is used by some AI approaches to explain this fact based on formal properties of the belief set (e.g., transitivity). Two experiments were designed to test the hypothesis that contrary to such views, (i) belief is naturally represented by degrees rather than in an all-or-nothing manner, (ii) entrenchment is primarily a matter of content and not only a matter of form, and (iii) consequently prior degree of belief is a powerful factor of change. The two experiments used Elio and Pelletier's (1997) paradigm in which participants were presented with full simple deductive arguments whose conclusion was denied, following which they were asked to decide which premise to revise.     

Work and Rest Variables in the Acquisition of Psychomotor Tracking Skill

College students (75 men, 75 women) matched in preliminary performance of 100 sec on the rotary pursuit apparatus were randomly assigned to five experimental groups. Their work/rest ratios, measured in seconds, were: 20/20, 30/30, 60/60, 90/90,120/120. All subjects received 30 min of total practice time after the matching trial. There was a significant practice effect and a significant practice x conditions interaction, but no main effect due to the cycles’ length or number. The decay rate of reactive inhibition (lr) is probably independent of its prior growth level; hence postrest residual lr is proportional to prerest accumulation. Partly because they generated lr in hypothetically greater amounts, women were significantly less proficient on the average than men, and sex interacted with practice. Although males had higher initial and final levels of ability than females, the two sexes’ acquisition curves showed the same rate parameters in our mathematical model.     

Facilitation of a Distributed Shuttle-Box Conditioning with Posttraining Intracranial Self-Stimulation in Old Rats

Old Wistar rats (16–17 months) were trained in a two-way active avoidance task for 5 consecutive days (10 trials/day). Immediately after each training session a lateral hypothalamic intracranial self-stimulation session (ICSS group) or a sham-treatment session (Control group) was given to the animals. Long-term retention was tested 7 days after the last acquisition session. ICSS treatment led to a significant improvement in acquisition. In the long-term retention session the level of avoidance in both groups was similar to that achieved in the last acquisition session, although differences among groups failed to reach statistical significance. These results are compared with those obtained in previous experiments with young adult rats. While ICSS facilitated the process of acquisition in both young and old rats (however, it was much more powerful in young animals), further experiments are needed to elucidate whether this effect is long-lasting in old rats, as occurs in young adult subjects.     

THE USE AND IMPACT OF PSYCHOLOGY IN VENEZUELA: TWO EXAMPLES

Two cases are presented to illustrate how psychological knowledge and technology have been used in Venezuela. The first case relates to the use of psychological technology in Venezuelan politics where it is possible to identify a change from “caudillismo” to a more democratic “voting against” political culture. There is evidence that imported political compaigning techniques and extensive use of polling have been a factor of some importance in such change. The second case refers to the activities of the Minister for the Development of Intelligence, who has started a group of projects to improve cognitive functioning in different age groups. These programs are too recent to ascertain their effectiveness; so data is reported on an opinionative evaluation of one of the projects, carried out among Venezuelan psychologists and pediatricians.     

Social factors influence haloperidol-induced catalepsy in rat

This study employed manipulations which presumably influence social interactions in rats: (1) paired housing with a heavier conspecific and (2) exposure to the odors of other rats. The dependent variable was the akinetic state induced by haloperidol, a neuroleptic and dopamine antagonist. In Experiment 1, adult male Long-Evans hooded rats were matched by weight and caged alone or in pairs with one rat 30 g heavier than its cagemate. All rats received haloperidol (1.5 mg/kg) and catalepsy testing. Heavy rats showed more catalepsy than the lighter member of pairs or weight-matched, singly housed controls. In Experiment 2, adult male rats were left unrecaged or were recaged into cages with bedding recently soiled by females or other adult males. After haloperidol (1.0 mg/kg), the rats exposed to bedding soiled by other adult males showed more catalepsy than did the control groups. Thus, the results of both experiments indicated that social factors can influence the akinesia induced by dopamine antagonists.     

Ideology,modernization and politico-economic development in Latin America

The authors state that social and political processes are continuously interrelated and modify each other in a circular fashion. The economic variable seems to be the most independent and strategic one in the complex and circular causal process of contemporary history. Its importance is due to the fact that economic forces have become the means that contribute the most to the attainment of varied social and political goals. holding appointments in the Department of International Relations, Economics, Political Science and Sociology/Anthropology. He is also a Senior Research Scholar at the University of Miami’s Graduate School of International Studies. He has been a Senior Fellow at Brookings Institution and is presently a staff member there. He has published more than thirty books and over one hundred articles.     

Effects of left-hand preference on postinjury measures of distal motor ability

The relationship of preinjury left-hand dominance for motor performance to postinjury distal motor skills following penetrating brain wounds in patients without overt hemiplegia was examined. We studied 13 controls, 13 right-hemisphere brain-damaged patients, and 11 left-hemisphere brain-damaged patients on motor tasks measuring reaction time, strength, and coordination. Our results indicated that no persistent deficits were seen on distal motor tasks in left-handed adults who suffered a penetrating brain wound. These findings are compatible with the relative sparing of persistent neuropsychological deficits in left-handers following brain damage.     

Preliminary validation of a Spanish language version of the Adoption Communication Scale in adopted adolescents / Validación preliminar de una versión en español de la escala Adoption Communication Scale para adolescentes adoptados

Abstract

The Adoption Communication Scale (ACS) is a 28-item child-report instrument used to assess adoptees’ perception of communication openness in the family. The aim was to develop a Spanish language version of the scale (ACS-S) and to assess the instrument’s psychometric properties in a sample of 55 adopted adolescents. The ACS-S was found to have high internal consistency (α = .93) and moderately high test-retest stability (.68). An exploratory factorial analysis yielded two factors, the first loaded on satisfaction with emotional communication items and the second encompassing satisfaction with the completeness of the information offered by the parents. These factors are coherent with the theory underlying the scale. The total ACS-S score was significantly positively correlated with adolescent Global Satisfaction with Openness as measured by a Visual Analogue Scale. The ACS-S scale appears to be a valid tool in assessing communication openness in Spanish adopted adolescents.     

The Proof by Cases Property and its Variants in Structural Consequence Relations

This paper is a contribution to the study of the rôle of disjunction in Abstract Algebraic Logic. Several kinds of (generalized) disjunctions, usually defined using a suitable variant of the proof by cases property, were introduced and extensively studied in the literature mainly in the context of finitary logics. The goals of this paper are to extend these results to all logics, to systematize the multitude of notions of disjunction (both those already considered in the literature and those introduced in this paper), and to show several interesting applications allowed by the presence of a suitable disjunction in a given logic.     

Measurement Invariance of Personal Well-Being Index (PWI-8) Across 26 Countries

This report examines the measurement invariance of the Personal Well-being Index with 8 items (PWI-8). University students (N = 5731) from 26 countries completed the measure either through paper and pencil or electronic mode. We examined uni-dimensional structure of PWI and performed a Multi-group CFA to assess the measurement invariance across the 26 countries, using conventional approach and the alignment procedure. The findings provide evidence of configural and partial metric invariance, as well as partial scalar invariance across samples. The findings suggest that PWI-8 can be used to examine correlates of life satisfaction across all included countries, however it is impossible to compare raw scores across countries.