Seasonality of suicide in Eastern Europe: a rejoinder to Lester and Moksony

Seasonality of suicide in Hungary decreased from the 1980s to the 1990s, supporting the 2003 conclusion of Lester and Moksony. However, it was the strongest ever to be documented with contemporary suicide data, supporting the conjecture of Voracek, et al. (2002) that seasonality of suicide remains high in Eastern Europe. A new hypothesis regarding the co-occurrence of high incidence and strong seasonality of suicide is presented.     

Psychometric properties of the Multidimensional Anxiety Scale for Children (MASC) among Icelandic schoolchildren

A psychometric assessment of the Icelandic version of the Multidimensional Anxiety Scale for Children (MASC) was undertaken among Icelandic schoolchildren, between 10 and 15 years of age. In a first study 625 children between 10 and 15 years of age filled in the MASC. A confirmatory factor analysis indicated that the four-factor structure of the instrument was justified. Further, means and standard deviations of the total scale and the subscales were similar to the original normative data reported by March (1997). In a second study the MASC, the Children Depression Inventory (CDI) and the Revised Children's Manifest Anxiety Scale (RCMAS) were administered to a sample of 249 schoolchildren between 10 and 15 years of age. The results supported the convergent and divergent validity of the MASC. Together the two studies show satisfactory psychometric properties of the Icelandic version of the MASC in a normal population.     

A non-finitely based quasi-variety of De Morgan algebras

In this paper we exhibit a non-finitely based, finitely generated quasi-variety of De Morgan algebras and determine the bottom of the lattices of sub-quasi-varieties of Kleene and De Morgan algebras.Supported by Vicerrectoría Académica de la Facultad de Ciencias and by División de Investigación, Sede Bogotá of the Universidad Nacional de Colombia.Special issue of Studia Logica: Algebraic Theory of Quasivarieties Presented by M. E. Adams, K. V. Adaricheva, W. Dziobiak, and A. V. Kravchenko     

Implicit learning of nonlocal musical rules: implicitly learning more than chunks

Dominant theories of implicit learning assume that implicit learning merely involves the learning of chunks of adjacent elements in a sequence. In the experiments presented here, participants implicitly learned a nonlocal rule, thus suggesting that implicit learning can go beyond the learning of chunks. Participants were exposed to a set of musical tunes that were all generated using a diatonic inversion. In the subsequent test phase, participants either classified test tunes as obeying a rule (direct test) or rated their liking for the tunes (indirect test). Both the direct and indirect tests were sensitive to knowledge of chunks. However, only the indirect test was sensitive to knowledge of the inversion rule. Furthermore, the indirect test was overall significantly more sensitive than the direct test, thus suggesting that knowledge of the inversion rule was below an objective threshold of awareness.     

Alternate response preparation in a visuomotor serial task

The preparation of a particular motor pattern is related to the information available that enables the actor to predict the correct response to a forthcoming stimulus. In many situations, however, prediction is not possible. In such cases, the individual can guess the probable parameters of the next stimulus. The authors attempted to establish the bias in the motor intention for movement and its interaction with a possible memory trace of the stimulus-response mapping produced by the preceding stimulus. Two letters were presented bilaterally, and participants (N=21) had to discriminate the target letter and respond with the compatible hand. The present findings support the existence of a memory trace of the previous stimulus-response mapping.     

An evaluation scale of family environment for identification of children at risk of school failure

This study describes the development of the Home Environment Resources Scale, a Brazilian measure for families with children ages 6 to 12 years. The scale measures aspects of support for school achievement, made available to the child at home. A first version of the measure with 11 subscales was administered to 100 mothers or guardians of children with poor school achievement in a clinical setting. Analysis of the items in the first version resulted in a final version comprising 8 subscales with acceptable indices of internal consistency. Two validity studies were conducted. One aimed at verifying to what extent the Home Environment Resources Scale could discriminate the home environment of students referred to a mental health clinic on account of poor school performance. The sample included mothers of 53 referred and 23 nonreferred children. The two groups differed significantly in home resources and on four subscales. The other study assessed the validity, i.e., prediction of the academic outcome of children entering Grade 1. 70 children and their mothers participated. Results indicate that school achievement and social competence at school are mediated by family support.     

Perceptual learning enhances retrospective revaluation of conditioned flavor preferences in rats

Forward and backward blocking of taste preference learning was compared in rats. In the forward condition, thirsty rats were exposed to a flavor (A) in sucrose solution (+) or in water (-), after which they were exposed to A in compound with another flavor (B) in sucrose solution (i.e., AB+). In the backward condition, these phases were reversed. Consumption of B alone was assessed when rats were food deprived. In the forward condition, rats given A+ consumed less B than rats given A-, providing evidence of forward blocking, whereas in the backward condition, rats given A+ drank more of B than those given A-. Subsequent experiments found that alternating but not blocked preexposure to A and B, when given prior to training, produced blocking of B whether A+ was given before or after AB+, suggesting that prior failures to observe backward blocking reflect failures of discrimination.     

Mother-infant relationships in baboons (Papio hamadryas): predictors of differences and discontinuities in developmental pathways

This study uses hierarchical linear regression modeling to analyze sources of variation in the developmental pathways of mother-infant relationships and to search for behavioral discontinuities. The data come from 23 mother-infant dyads of baboons (Papio hamadryas), whose interactions were recorded longitudinally during the infants' 1st year of life. The infant's sex and the mother's age and reproductive experience accounted for part of the variation observed in the developmental pathways of 11 of 20 behavioral measures analyzed; however, some of them did so only in some periods but not in others. The authors proposed that this can reflect the occurrence of reorganizations or discontinuities in the mother-infant relationship that can be related to important life events such as the mother's resumption of sexual activity.     

Activation of adenosine receptors in the posterior cingulate cortex impairs memory retrieval in the rat

Adenosine A1 and A2A receptor agonists and antagonists have been reported to alter learning and memory. The aim of our study was to investigate the involvement of adenosinergic system in memory retrieval into posterior cingulate cortex (PCC) of Wistar rats. To clarify this question, we tested specifics agonist and antagonists of adenosine A1 and A2A receptors in rats submitted to a one-trial inhibitory avoidance task. The stimulation of adenosine A1 and A2A receptors by CPA and CGS21680, respectively, impaired memory retrieval for inhibitory avoidance task, into PCC. These findings provide behavioral evidence for the role of adenosinergic system in the memory retrieval into PCC.