Motor skill acquisition during a balance task as a process of optimization of motor primitives.

It has been argued that the central nervous system relies on combining simple movement elements (i.e. motor primitives) to generate complex motor outputs. However, how movement elements are generated and combined during the acquisition of new motor skills is still a source of debate. Herein, we present results providing new insights into the role of movement elements in the acquisition of motor skills that we obtained by analysing kinematic data collected while healthy subjects learned a new motor task. The task consisted of playing an interactive game using a platform with embedded sensors whose aggregate output was used to control a virtual object in the game. Subjects learned the task over multiple blocks. The analysis of the kinematic data was carried out using a recently developed technique referred to as "movement element decomposition." The technique entails the decomposition of complex multi-dimensional movements in one-dimensional elements marked by a bell-shaped velocity profile. We computed the number of movement elements during each block and measured how closely they matched a theoretical velocity profile derived by minimizing a cost function accounting for the smoothness of movement and the cost of time. The results showed that, in the early stage of motor skill acquisition, two mechanisms underlie the improvement in motor performance: 1) a decrease in the number of movement elements composing the motor output and 2) a gradual change in the movement elements that resulted in a shape matching the velocity profile derived by using the above-mentioned theoretical model.

Quality of life in schizophrenia: a multicenter, randomized, naturalistic, controlled trial comparing olanzapine to first-generation antipsychotics.

OBJECTIVE: To assess the effectiveness of olanzapine for treating schizophrenia and to assess if olanzapine promotes a better quality of life than first-generation antipsychotics (FGAs). METHOD: Multicenter, naturalistic, randomized controlled study, comparing olanzapine with FGAs, at hospitalization and during a 9-month follow-up. Outcome assessors were blind to the allocated drug. The dose of antipsychotic was determined by doctors according to their clinical practice routines. Data collection was performed from April 1999 to August 2001. RESULTS: 197 patients with DSM-IV-diagnosed schizophrenia were allocated to olanzapine (N = 104) and FGA (N = 93). Patients taking olanzapine showed greater improvements in Positive and Negative Syndrome Scale (PANSS) negative symptoms (mean difference = 2.3, 95% CI = 0.6 to 4.1) and general psychopathology (mean difference = 4.0, 95% CI = 0.8 to 7.2) sub-scales and fewer incidences of tardive dyskinesia (RR = 2.4, 95% CI = 1.4 to 4.2, p < .0001). Olanzapine was also associated with greater improvement in a number of health-related quality-of-life outcomes on the Medical Outcomes Study 36-item Short-Form Health Survey, including physical functioning (mean difference = 6.6, 95% CI = 1.2 to 11.9), physical role limitations (mean difference = 13.7, 95% CI = 3.0 to 24.3), and emotional role limitations (mean difference = 12.1, 95% CI = 0.7 to 23.5). Patients taking olanzapine gained significantly more weight during the trial than patients taking FGAs, with a correspondent endpoint increase in the body mass index (BMI) of 28.7 versus 25.3 (p < .001). CONCLUSION: Compared with FGAs, olanzapine has advantages in terms of improvements of negative symptoms and quality of life. It is also associated with fewer incidences of tardive dyskinesia and greater increases in weight and BMI. These findings are highlighted by the naturalistic approach adopted in this trial.

Uso da associacao carbomazepina-buspirona na dependencia do alcool / Use of carbamazepine-buspirone combination in alcohol dependence

Setenta e quatro dentre os 117 pacientes atendidos no ambulatorio para alcoolistas de um hospital universitario, apresentaram os criterios do DSM-III-R para dependencia do alcool e foram tratados com a associacao carbamazepina-buspirona durante seis meses. Aqueles que nao completaram esse periodo foram considerados como insucesso terapautico, de acordo com o principio de intencao-de-tratar. Verificou-se que 47,3 por cento apresentaram remissao parcial (8,1 por cento) ou total (39,2 por cento). Tanto a carbamazepina quanto a buspirona foram bem toleradas pelos pacientes em doses que variavam entre 400 a 800 mg/dia e 10 a 40 mg/dia, respectivamente.