Impairment of movement execution in Parkinson's disease could be due to disorders of cognition and/or of activation. These two factors are hard to separate by measuring response times only. Therefore, in this study response force and event-related EEG potentials were measured continuously during tasks in which subjects had to respond to cued signals. Fifteen patients with Parkinson's disease an...

In [17] it was suggested that the number of limit cycles in a piecewise-linear system could be closely related to the number of zones, that is the number of parts of the phase plane where the system is linear. In this note we construct an example of a class of perturbed piecewise systems with n zones such that the first variation of the displacement function is identically zero. Then we conject...

Previous research documented a robust link between difficulties in self-regulation and development of externalizing problems (i.e., aggression and delinquency). In this study, we examined the longitudinal additive and interactive genetic and environmental covariation underlying this well-established link using a twin design. The sample included 131 pairs of monozygotic twins and 173 pairs of sa...

This article gives dual representations for convex integral functionals on the linear space of regular processes. This space turns out to be a Banach space containing many more familiar classes of stochastic processes and its dual is identified with the space of optional Radon measures with essentially bounded variation. Combined with classical Banach space techniques, our results allow for sys...