Does Transcranial Direct Current Stimulation Affect the Learning of a Fine Sequential Hand Motor Skill with Motor Imagery?

Learning a fine sequential hand motor skill, like playing the piano or learning to type, improves not only due to physical practice, but also due to motor imagery. Previous studies revealed that transcranial direct current stimulation (tDCS) and motor imagery independently affect motor learning. In the present study, we investigated whether tDCS combined with motor imagery above the primary motor cortex influences sequence-specific learning. Four groups of participants were involved: an anodal, cathodal, sham stimulation, and a control group (without stimulation). A modified discrete sequence production (DSP) task was employed: the Go/NoGo DSP task. After a sequence of spatial cues, a response sequence had to be either executed, imagined, or withheld. This task allows to estimate both non-specific learning and sequence-specific learning effects by comparing the execution of unfamiliar sequences, familiar imagined, familiar withheld, and familiar executed sequences in a test phase. Results showed that the effects of anodal tDCS were already developing during the practice phase, while no effects of tDCS on sequence-specific learning were visible during the test phase. Results clearly showed that motor imagery itself influences sequence learning, but we also revealed that tDCS does not increase the influence of motor imagery on sequence learning.     

Temperament and Anxiety: The Mediating Role of Metacognition

The present study examines a simple model for the relationship between temperament, anxiety and maladaptive metacognition. A clinical sample of patients diagnosed with anxiety disorders (n?=?216) completed a set of self-reported questionnaires measuring temperament dimensions, state anxiety and metacognitions. Three temperament traits were included in the hypothesized model: emotional reactivity, perseveration and briskness. A structural equation modeling analysis supported a model in which the relationship between the three temperament traits and anxiety were fully mediated by metacognition. Dissimilar models were identified for the male and female subgroups, and also with reference to individual categories of maladaptive metacognition. The findings support the significance of metacognition as a factor influencing the temperament-anxiety relationship. Moreover, they confirm the roles both of emotional reactivity and of perseveration, being major traits related to anxiety which also turned out to be strongly associated with metacognition. In case of the models for the categories of metacognition, emotional reactivity was associated with negative beliefs, perseveration with negative and positive beliefs, while briskness predicted anxiety independently of metacognition. These results suggest the existence of more specific associations between temperament traits, anxiety, and various types of metacognition.     

Comparing Semantics of Logics for Multi-Agent Systems

We draw parallels between several closely related logics that combine — in different proportions — elements of game theory, computation tree logics, and epistemic logics to reason about agents and their abilities. These are: the coalition game logics CL and ECL introduced by Pauly 2000, the alternating-time temporal logic ATL developed by Alur, Henzinger and Kupferman between 1997 and 2002, and the alternating-time temporal epistemic logic ATEL by van der Hoek and Wooldridge (2002). In particular, we establish some subsumption and equivalence results for their semantics, as well as interpretation of the alternating-time temporal epistemic logic into ATL. The focus in this paper is on models: alternating transition systems, multi-player game models (alias concurrent game structures) and coalition effectivity models turn out to be intimately related, while alternating epistemic transition systems share much of their philosophical and formal apparatus. Our approach is constructive: we present ways to transform between different types of models and languages.     

On Reduction Systems Equivalent to The Lambek Calculus with the Empty String

The paper continues a series of results on cut-rule axiomatizability of the Lambek calculus. It provides a complete solution of a problem which was solved partially in one of the author's earlier papers. It is proved that the product-free Lambek Calculus with the empty string (L ₀) is not finitely axiomatizable if the only rule of inference admitted is Lambek's cut rule. The proof makes use of the (infinitely) cut-rule axiomatized calculus C designed by the author exactly for this purpose.     

Husserl bibliography

International Academy of Philosophy Principality of Liechtenstein