Table 2.

General parameters and results of tACS/tRNS studies.

Reference	Sample size	Electrode position and size	Stimulation parameters	Stimulation frequency	Timepoint of data acquisition	Paradigm	Results
Neuling et al., 2012a	20	T7 and T8, 35 cm2	Below individual sensation threshold for 21 min	Oscillatory tDCS (10 Hz)	Online	Auditory threshold detection	Phase dependent detection thresholds; improved performance with stimulus presentation at 0–180° and hampered performance at 180–360°
Riecke et al., 2015	14	T7 and T8, 25 cm2 and left and right to Cz, 35 cm2	Below individual sensation threshold for 40 min	4 Hz	Online	Auditory threshold detection	tACS phase dependent detection thresholds; improved performance with stimulus presentation at 0–180° and hampered performance at 180–360°
Rufener et al., 2016	35	T7 and T8, 35 cm2	Below individual sensation threshold for 20 min	40 Hz, 6 Hz	Offline	VOT-categorization	40 Hz tACS impaired VOT-categorization ability
Schaal et al., 2015	17	Right DLPFC and contralateral orbit, 25 cm2	1 mA for 20 min	35 Hz, 90 Hz	Offline	Pitch memory	35 Hz tACS facilitated pitch memory, leading to comparable performance in congenital amusics and controls
Van Doren et al., 2014	14	T7 and T8, 35 cm2	2 mA for 20 min	tRNS (100–640 Hz)	Offline	Auditory steady state response (ASSR)	Increased ASSR-response to 40 Hz frequency-modulated tone

VOT, voice onset time; DLPFC, dorsolateral prefrontal cortex; electrode positions refer to the international 10–20 system.