Effect of tDCS on Fine Motor Control of Patients in Subacute and Chronic Post-Stroke Stages

Abstract

In this study we compared the effects of transcranial direct current stimulation (tDCS) in the subacute and chronic stages of post-stroke recovery. Anodal/sham tDCS was applied to the primary motor cortex of stroke patients in these stages of recovery in a cross-over design. The Jebsen–Taylor hand function test was employed. The repeated-measure ANOVA showed significant influence of the stimulation type and test performance time (during/after tDCS) with no overall influence of recovery stage. The interaction TYPE*TIME*STAGE was significant. The effect after anodal tDCS in the subacute stage was significantly higher compared to the effects in all relevant conditions including the chronic stage. Therefore, tDCS treatment in the subacute stage of recovery can be superior, at least for some patients, to treatment in the chronic stage.     

Daily Time-Place Learning in Young Children

Abstract

Pre-school children find it difficult to correctly report if it is morning or afternoon. The present study tested whether children could learn a non-verbal Time-Place Learning (TPL) task that depended on time of day. Twenty-five 4-year-olds were repeatedly asked to find a toy in one of two boxes. Children in the Cued condition were told the toy was in one box in the morning and in another box in the afternoon. Children in the Not Cued condition were told the toy was sometimes in one box and sometimes in the other box. After 80 trials, children were asked if it was morning or afternoon. About 65% of the children learned the TPL task, and about three-quarters of the children verbally identified if it was morning or afternoon. However, the children who learned the TPL task were not necessarily the children who correctly answered whether it was morning or afternoon, and those in the Cued condition were no more likely to solve the task than those in the Not Cued condition. The implication is that children have a sense of time that can be used to solve spatio-temporal contingencies, but does not depend on the verbal understanding of time of day.     

A BIOSEMIOTIC APPROACH TO THE QUESTION OF MEANING

A sign is something that refers to something else. Signs, whether of natural or cultural origin, act by provoking a receptive system, human or nonhuman, to form an interpretant (a movement or a brain activity) that somehow relates the system to this “something else.” Semiotics sees meaning as connected to the formation of interpretants. In a biosemiotic understanding living systems are basically engaged in semiotic interactions, that is, interpretative processes, and organic evolution exhibits an inherent tendency toward an increase in semiotic freedom. Mammals generally are equipped with more semiotic freedom than are their reptilian ancestor species, and fishes are more semiotically sophisticated than are invertebrates. The evolutionary trend toward the production of life forms with an increasing interpretative capacity or semiotic freedom implies that the production of meaning has become an essential survival parameter in later stages of evolution.     

Relative importance of criteria: a quantitative approach

A mathematical definition for the assertion ‘a group of criteria A is more important than a group of criteria B’ is introduced. It is shown how quantitative information on relative importance of criteria allows us to obtain a more precise upper estimate for a set of all non-dominated solutions than the well-known Pareto set. © 1997 John Wiley & Sons, Ltd.