Behavioral and physiological on- and offline effects of transcranial alternating current stimulation

Non-invasive techniques to modulate brain activity are increasingly used in neuroscience. In the scope of this dissertation, the results of four experiments are presented. The Experiments investigated effects of transcranial alternating current stimulation (tACS) on human brain oscillations, occurring after and during stimulation. The first two studies showed, that tACS can enhance brain oscillations in the range of the stimulated frequency band for up to 70 minutes. This effect was also demonstrated in the presence of a cognitive task, where it was accompanied by a modulation of task performance. Studies 3 and 4 were concerned with approaches to reduce artifacts in concurrent recordings of EEG/MEG during stimulation. In study 3 an enhancing effect of tACS on event-related oscillations was found during stimulation.