José Ramón Alameda Bailén

Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance

Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS—namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

Mecanismos cognitivos de la toma de decisiones en mujeres mayores

The Damasios somatic marker hypothesis focuses on the possible influence of the emotional states on the decision making processes. An assessment tool derived form this theory is the Iowa Gambling Task (IGT). The aim of this study was to detect decision-making alterations in relation to the cognitive impairment associated to age (GDS 2). The data analysis was conducted from two perspectives: quantitative, by computing the advantageous versus disadvantageous choices; and qualitative, according to the PVL model parameters. Two groups were analyzed: one consisting of elderly women with cognitive impairment, and another, with no impairment. Regarding the quantitative analysis, the results show significant differences between both groups, indicating that women with cognitive impairment have less advantageous choices than women without impairment; however, from a qualitative point of view, the results show no significant differences between groups in any of the four parameters of the PVL, indicating that execution of women with and without cognitive impairment are similar. In conclusion, it can be argued that the decision-making processes in women with and without cognitive impairment are quantitatively different but qualitatively similar.

Independence of basic arithmetic operations: Evidence from cognitive neuropsychology

Resumen es: Los casos descritos en la literatura ponen de manifiesto que las operaciones aritmeticas pueden funcionar independientemente, lo que pe r- mite inferir q...