Development of lateral asymmetry in the perception of sequentially touched fingers

In order to investigate lateral asymmetry in tactile perception, two or four fingers of normal primary school children were touched sequentially. Stimulation was either unimanual or bimanual and either verbal or nonverbal responses were required. Right hand advantage was demonstrated subsequent to uni- and bimanual stimulation in both the verbal and nonverbal response conditions. Neither an age nor a sex effect on laterality was found. Right hand advantage was affected by direction of stimulation in the bimanual condition. Left hemispheric dominance was argued to be related to the temporal nature of the tasks.     

The integration of family therapy in a psychiatric day hospital

The clients, who present themselves at our psychiatric day hospital in Amsterdam, often have long-standing problems. These problems are usually of a complex nature, and the age of the clients plays an imporant role in this. Their age varies from seventeen to forty, with an average of twenty-eight.
Efforts were made over a long period to facilitate solutions to the clients' family conflicts. During this time an extensive range of problems within the family were presented of which the symptoms of the client represent just a part.
Working as a family therapist in a psychiatric day hospital, where clients are admitted individually, places the family therapist in a number of dilemmas, especially when many working in the hospital see the problems only as individual ones.     

Work, Competences and Learning Scenarios for the Future

Il arrive que les occasions d'apprentissage et d'acquisition des compétences et des aptitudes soient tiées aux opportunités professionnelles et ainsi, indirectement, au développement de l'économie. L auteur illustre, avec cinq scénarios, comment l'apprentissage peut être conditionné par des choix macro-économiques et macro-sociaux.
Opportunities for learning and the acquisition of competences or skills happen to be linked to work opportunities and thence indirectly to the development of the economy. The author sketches five scenarios indicating how learning may be conditioned by macroeconomic and macro-social choices.     

Exposure to violence and suicide risk in adolescents: a community study

The prevalence of violence exposure is relatively unexplored in adolescents in European communities, and reports on the association between exposure to community violence and suicidal behavior are rare. The aim of this study was to investigate (1) the prevalence of community violence in a European urban adolescent sample, (2) the relationship between exposure to community violence and suicidal ideation/deliberate self-harm, and (3) the influence of depressive symptoms and aggressive behavior on this relationship. Self-report surveys were administered to a representative school-based sample of 1509 adolescents in Antwerp (Belgium). The prevalence rate of violence exposure was still high but lower than that reported in U.S. communities. Suicidal ideation and deliberate self-harm were both related to violence exposure. The gender-specific influence of depressive symptomatology and aggressive behavior on the association between exposure to violence and suicidal behavior suggests the need for further research.     

Timing precision in continuation and synchronization tapping

 Wing and Kristofferson (1973) have shown that temporal precision in self-paced tapping is limited by variability in a central timekeeper and by variability arising in the peripheral motor system. Here we test an extension of the Wing–Kristofferson model to synchronization with periodic external events that was proposed by Vorberg and Wing (1994). In addition to the timekeeper and motor components, a linear phase correction mechanism is assumed which is triggered by the last or the last two synchronization errors. The model is tested in an experiment that contrasts synchronized and self-paced trapping, with response periods ranging from 200–640 ms. The variances of timekeeper and motor delays and the error correction parameters were estimated from the auto-covariance functions of the inter-response intervals in continuation and the asynchronies in synchronization. Plausible estimates for all parameters were obtained when equal motor variance was assumed for synchronization and continuation. Timekeeper variance increased with metronome period, but more steeply during continuation than during synchronization, suggesting that internal timekeeping processes are stabilized by periodic external signals. First-order error correction became more important as the metronome period increased, whereas the contribution of second-order error correction decreased. It is concluded that the extended two-level model accounts well for both synchronization and continuation performance. Received: 16 November 1998 / Accepted: 21 April 1999     

Learning-induced arg 3.1/arc mRNA expression in the mouse brain

The effector immediate-early gene (IEG) arg 3.1, also called arc, encodes a protein interacting with the neuronal cytoskeleton. The selective localization of arg 3.1/arc mRNA in activated dendritic segments suggests that the arg 3.1/arc protein may be synthesized at activated post-synaptic sites and that arg 3.1/arc could participate in structural and functional modifications underlying cognitive processes like memory formation. To analyze whether learning itself is sufficient to trigger expression of arg 3.1/arc, we developed a one-trial learning paradigm in which mice learned to enter a dark compartment to escape from an aversively illuminated area. Arg 3.1/arc mRNA expression was analyzed by in situ hybridization in three groups of mice as follows: a control group with no access to the dark compartment, a learning group having access to the dark compartment for one trial, and a retrieval group having access to the dark compartment for two trials on consecutive days. All animals from the learning and retrieval groups escaped the illuminated area, and those tested 24 h later (retrieval group) showed a strongly reduced latency to enter the dark compartment, demonstrating the validity of our learning paradigm to induce long-term memory. Our results show that acquisition of a simple task results in a brain area-specific biphasic increase in arg 3.1/arc mRNA expression 15 min and 4.5 h post-training. This increase was detected specifically in the learning group but neither in the control nor in the retrieval groups. The pattern of arg 3.1/arc mRNA expression corresponds temporally to the two mRNA- and protein-synthesis-dependent periods of long-term memory formation. Our study provides the first unequivocal evidence that arg 3.1/arc expression is induced by a learning task and strongly suggests a role of arg 3.1/arc mRNA in the early and late cellular mechanisms underlying the stabilization of the memory trace.