Table 2.
Partial parameters and results of auditory process studies.
Reference | Sample Size | Stimulation Types | Stimulation Position and Electrode Size | Reference Electrode Position and Size | Stimulation Parameters | The Number of Stimulation Sessions | EEG Recording Time | Auditory Paradigm | Results |
---|---|---|---|---|---|---|---|---|---|
Ladeira, et al., 2011 [61] | 11 | tDCS: anodal/cathodal/sham | Simultaneous T3 and T4, 35 cm2 |
Contralateral deltoid muscle 35 cm2 | 2.0 mA for 10 min | Three stimulation sessions | unspecified | Random gap detection test | Anodal tDCS enhanced temporal resolution and cathodal diminished temporal resolution |
Heimrath, et al., 2014 [62] | 15 | tDCS: anodal/sham | T7, T8, 25 cm2 | Contralateral C4, C3, 50 cm2 | 1.5 mA for 13 min | Two stimulation sessions | unspecified | Between channel gap detection task | Anodal tDCS over the left auditory cortex diminished temporal resolution |
Baltus, et al., 2018 [65] | 26 | IGF ± 4 Hz tACS | Left hemispheric: FC5 and TP7/P7 Right hemispheric: FC6 and TP8/P8 Each hemispheric two round electrodes (2.5 cm diameter) |
unspecified | 1.0 mA for 7 min | Each participant had one stimulation session within two days | Day 1: 40 min in the IGF estimation. Day 2: 1.5 min in the aftereffect estimation. |
Between channel gap detection task | Participants in Group A (tACS frequency above IGF) performed significantly better during tACS compared to participants in Group B (tACS frequency below IGF) Both groups had significant relative changes in the amplitude of ASSR |
Baltus, et al., 2020 [66] | 16 | IGF + 3 Hz tACS or IGF − 4 Hz tACS |
Left hemispheric: FC5 and TP7/P7 Right hemispheric: FC4 and TP8/P8 Each hemispheric two round electrodes (2.5 cm diameter) |
unspecified | 1.0 mA for 8.5 ± 1.7 min | Each participant had two stimulation sessions within two days | Day 1: 20 min in the IGF estimation. | Between channel gap detection task | The IGF was significantly related to the gap detection performance under the condition that the baseline and tACS frequency were higher than IGF 3 Hz Under the condition that the tACS frequency was higher than IGF 3 Hz, tACS could modulated gap detection performance |
Rufener, et al., 2017a [67] | 20 | HF-tRNS (100–640 Hz)/sham | Over T7 and T8 35 cm2 | unspecified | 1.5 mA for 40 min | Two stimulation sessions. Stimulation twice in each session. | Record EEG during gap task and pitch task. Unspecified time. | Between channel gap detection task and pitch discrimination task. | Auditory tRNS only increased the detection rate in the temporal domain, no such effect on the discrimination of spectral features The facilitation effect of tRNS was limited to the processing of stimuli near the threshold |
Rufener, et al., 2017b [68] | 18 | tRNS/sham unspecified frequency | LAC, RAC, BAC unspecified size | unspecified | 1.5 mA for 30 min | Four stimulation sessions. | tRNS simultaneous EEG About 30 min |
Between channel gap detection task and pitch discrimination task. | The application of tRNS on LAC and BAC was related to task performance LAC had functional relevance when dealing with temporal features, and this effect was modulated by the the inter-tone interval between the tone triplets |
Lewald 2016 [70] | 74 | tDCS: anodal and cathodal/sham | (1) superior temporal gyrus (STG, n = 24) (2) inferior parietal lobule (IPL, n = 28) (3) somatosensory-motor cortex (SMC, n = 22). Two round electrodes (diameter 21 mm, 3.5 cm2) |
unspecified | 0.4 mA for 12 min | Each participant had one stimulation session at a different stimulation site | unspecified | Simulated “cocktail-party” situation | The tDCS over superior temporal gyrus could enhance the accuracy of target localization in left hemispace TDCS over IPL and off-target active stimulation over SMC found no significant effects |
Lewald 2019 [71] | 24 | tDCS: anodal/sham | Midpoint between C5 and T7 locations and C6 and T8 locations 35 cm2 | over the contralateral shoulders 7 × 14 cm | 1.0 mA for 32 min | Two stimulation sessions | unspecified | Simulated “cocktail-party” situation | TDCS over the region of posterior STG, significantly improved the performance in localizing a target speaker Compared with sham tDCS, the average increase in correct responses by 3.7% after active tDCS |
Hanenberg, et al., 2019 [72] | 39 | tDCS: anodal/cathodal/sham | Midpoint between C6 and T8 35 cm2 | over the contralateral shoulder(left) 7 × 14 cm | 1.0 mA for 16 min | Three stimulation sessions. | Whole session about 91 min; | Simulated “cocktail-party” situation | The amplitude of the response of the N2 component on the contralateral (left) increased significantly within 15 min after tDCS At the same point in time, the posterior parietal cortex (PPC) electrical activity reduced on the same side (right) |
Malte, et al., 2018 [78] | 20 | 10 Hz tACS and sham or 47 Hz tACS and sham | FC5 and TP7 Round electrodes of 3 cm diameter | unspecified | 1.0 mA for 25 min | Each participant received two sessions, each session included one sham and one real tACS | unspecified | Dichotic listening task | Unihemispheric α-tACS relatively reduced the recall of targets contralateral to stimulation, increased recall of ipsilateral targets Contrary to α-tACS, γ-tACS relatively increased the recall of targets contralateral to stimulation, decreased recall of ipsilateral targets |
Deng, et al., 2019 [79] | 38 | 10 Hz HD-tACS/6 Hz HD-tACS/sham | P2 ring electrode unspecified size | CP2, P4, Pz, PO4 ring electrode unspecified size | 1.5 mA for 20 min | Each participant received one sham and one HD-tACS | unspecified | Selective auditory attention task | RIPS’ α-HD-tACS disrupts auditory spatial attention for leftward No effect on performance in the myriad control conditions (i.e., gender, continuous/switching experiment, theta stimulation) |
Rufener, et al., 2018 [82] | 20 | HF-tRNS (100–640 Hz)/sham | F3 25 cm2 | right shoulder 35 cm2 | 1.5 mA for 30 min executed twice per session | Two stimulation sessions. | tRNS simultaneous EEG About 60 min |
Oddball paradigm (target tone recognition) | TRNS regulates the excitability of the left DLPFC TRNS reduced the subject’s response time to identify the target sound, and fastened up the latency of the P3 component |