Polarity-Dependent Transcranial Direct Current Stimulation Effects on Central Auditory Processing

Given the polarity dependent effects of transcranial direct current stimulation (tDCS) in facilitating or inhibiting neuronal processing, and tDCS effects on pitch perception, we tested the effects of tDCS on temporal aspects of auditory processing. We aimed to change baseline activity of the auditory cortex using tDCS as to modulate temporal aspects of auditory processing in healthy subjects without hearing impairment. Eleven subjects received 2mA bilateral anodal, cathodal and sham tDCS over auditory cortex in a randomized and counterbalanced order. Subjects were evaluated by the Random Gap Detection Test (RGDT), a test measuring temporal processing abilities in the auditory domain, before and during the stimulation. Statistical analysis revealed a significant interaction effect of time vs. tDCS condition for 4000 Hz and for clicks. Post-hoc tests showed significant differences according to stimulation polarity on RGDT performance: anodal improved 22.5% and cathodal decreased 54.5% subjects' performance, as compared to baseline. For clicks, anodal also increased performance in 29.4% when compared to baseline. tDCS presented polarity-dependent effects on the activity of the auditory cortex, which results in a positive or negative impact in a temporal resolution task performance. These results encourage further studies exploring tDCS in central auditory processing disorders

Falsa memória e autismo: qual é a extensão dos déficits semânticos?

En las últimas décadas el interés por la investigación de la falsa memoria se ha ampliado. Sin embargo, se observan pocos estudios que investigan los componentes electrofisiológicos subyacentes implicados en el reconocimiento verdadero y el falso, especialmente con respecto a los pacientes con autismo. Este artículo tiene como ob-jetivo presentar los estudios de investigación de la falsa memoria y procesamiento se-mántico en las personas con desarrollo típico a través del uso de la electroencefalogra-fía, además de presentar la literatura restringida sobre el tema en los pacientes con autismo. Existe un debate acerca de los déficits semánticos en el autismo, pero hay pocos estudios en esta área y con resultados contradictorios. Por último, se presentan nuevas direcciones para el desarrollo y mejora de nuevos estudios

RGDT performance considering time and the type of stimulation (mean ±SEM).

<p>1A presents performance during 4000 Hz. * p = 0.04 for the comparison between performance during anodal tDCS and anodal baseline and between performance during cathodal tDCS and cathodal baseline. 1B presents performance during Clicks. * p = 0.015 for the comparison between performance during anodal tDCS and anodal baseline. ** p = 0.002 and p = 0.04 for performance during anodal tDCS in comparison to cathodal and sham tDCS, respectively.</p