Association between anxiety and depression in children and adolescents with anxiety disorders

The relationship between anxiety and depression was examined in a sample of 106 children and adolescents referred to an outpatient anxiety disorder clinic for children. Twenty-eight percent of patients with DSM-III diagnoses of anxiety disorders displayed a concurrent major depression. Children with anxiety disorders plus major depression were found (1) to be older, (2) to demonstrate more severe anxiety symptomatology, and (3) to be diagnosed with different rates of certain anxiety-disorder subtypes, when compared to anxious patients without major depression. Nondepressed anxious children and adolescents did not differ from a psychopathological control group in severity of either anxiety or depression symptoms.     

Canonical analysis of two convex polyhedral cones and applications

Canonical analysis of two convex polyhedral cones consists in looking for two vectors (one in each cone) whose square cosine is a maximum. This paper presents new results about the properties of the optimal solution to this problem, and also discusses in detail the convergence of an alternating least squares algorithm. The set of scalings of an ordinal variable is a convex polyhedral cone, which thus plays an important role in optimal scaling methods for the analysis of ordinal data. Monotone analysis of variance, and correspondence analysis subject to an ordinal constraint on one of the factors are both canonical analyses of a convex polyhedral cone and a subspace. Optimal multiple regression of a dependent ordinal variable on a set of independent ordinal variables is a canonical analysis of two convex polyhedral cones as long as the signs of the regression coefficients are given. We discuss these three situations and illustrate them by examples.     

The rhetorical foundation of philosophical argumentation

The rejection of rhetoric has been a constant theme in Western thought since Plato. The presupposition of such a debasement lies at the foundation of a certain view of Reason that I have called propositionalism, and which is analyzed in this article. The basic tenets of propositionalism are that truth is exclusive, i.e. it does not allow for any alternative, and that there is always only one proposition which must be true, the opposite one being false. Necessity and uniqueness are the ideals of propositionalism. But the question of the necessity of such a necessity is bound to arise. Foundationalism and propositionalism are intrinsically related. Since necessity excludes alternatives, rhetoric, which is based on the possibility of opposite standpoints, is unavoidably devalued as the crippled child of Reason, identical to sophistry or eristic. But propositionalism cannot justify itself and provide a justification for its own foundation without circle or contraditction. Since it responds to the problem of eradicating problems and alternatives through propositional entities, propositionalism is ultimately based on questioning to which it replies in the mode of denial. The unavowed foundation of Reason is therefore the question of questioning, even though this very question is suppressed as propositionalism. The trace of such a question is not only historical, but can also be seen, for instance, in the role played by the principle of contradiction in the constitution of propositional Reason (Artitotle): opposite propositions are not the expression of a problematic situation, they are either possible or successively unique propositions.We want to replace propositionalism by problematology which allows for the conceptualization of alternatives, thereby rendering a true rhetoric possible. Argumentation cannot then be equated with eristic any more, as propositionalism maintained.Rationality must be seen as having questioning as its true starting-point. Reason must be rhetorical if it is to survive the death of propositionalism which took place after the radical criticisms of Marx, Nietzsche and Freud. Even if it is still hard ffor philosophers and rhetoricians to think within another framework and even though they prefer endlessly to deconstauct the old one instead of changing it, problematology is bound to impose itself as the new voice for rationality, because Reason has always endeavored to solve problems. Propositionalism has been only one way of conceiving problems, based on the view that solutions could be but the suppression of questioning.     

On the transmission of partial information: inferences from movement-related brain potentials.

Results are reported from a new paradigm that uses movement-related brain potentials to detect response preparation based on partial information. The paradigm uses a hybrid choice-reaction go/nogo procedure in which decisions about response hand and whether to respond are based on separate stimulus attributes. A lateral asymmetry in the movement-related brain potential was found on nogo trials without overt movement. The direction of this asymmetry depended primarily on the signaled response hand rather than on properties of the stimulus. When the asymmetry first appeared was influenced by the time required to select the signaled hand, and when it began to differ on go and nogo trials was influenced by the time to decide whether to respond. These findings indicate that both stimulus attributes were processed in parallel and that the asymmetry reflected preparation of the response hand that began before the go/nogo decision was completed.     

On the Relation Between Time Perception and the Timing of Motor Action: Evidence for a Temporal Oscillator Controlling the Timing of Movement

Studies of time estimation have provided evidence that human time perception is determined by an internal clock containing a temporal oscillator and have also provided estimates of the frequency of this oscillator (Treisman, Faulkner, Naish, & Brogan, 1992; Treisman & Brogan, 1992). These estimates were based on the observation that when the intervals to be estimated are accompanied by auditory clicks that recur at certain critical rates, perturbations in time estimation occur. To test the hypothesis that the mechanisms that underlie the perception of time and those that control the timing of motor performance are similar, analogous experiments were performed on motor timing, with the object of seeing whether evidence for a clock would be obtained and if so whether its properties resemble those of the time perception clock. The prediction was made that perturbations in motor timing would be seen at the same or similar critical auditory click rates. The experiments examined choice reaction time and typing. The results support the hypothesis that a temporal oscillator paces motor performance and that this oscillator is similar to the oscillator underlying time perception. They also provide an estimate of the characteristic frequency of the oscillator.     

Comparative analysis of actual and mental movement times in two graphic tasks

This study compared the temporal organization of graphic movements executed either actually or mentally. Six subjects had to perform two tasks, writing a sentence and drawing a cube, either as a real performance or as an imagined one, with either the right or the left hand, and with either a small or a large tracing amplitude. In the same subject, for the same hand, mental and actual movement times were both very stable and very close from trial to trial regardless of the tracing amplitude. Thus, mental movements mimic closely real movements in their temporal organization and are likely to involve the same planning program.