Table 1.
Brain stimulation study results.
| Author | N dyads | Type of stimulation | Stimulation conditions | Stimulation target | Task | Outcome | |
|---|---|---|---|---|---|---|---|
| Neural | Behavioral | ||||||
| Chen et al. (2022) | 27 (experiment 2) | Dual-tACS | 40 Hz in-phase, sham (between-subjects) | Left STG | tACS during rest and semiotic game | NA | No significant differences in number of people in success / failure group; Accuracy higher for tACS vs. sham in success but not failure group |
| Liu et al. (2023) | 70 (experiment 3) | Dual-tACS | 40 Hz in-phase, 40 Hz anti-phase, sham (between-subjects) | Right STG | tACS prior to coordinating symbolic communication task | Higher INS in right STG during baseline and task for in-phase compared to anti-phase and sham stimulation | Communicative accuracy higher for in-phase compared to sham and anti-phase stimulation |
| Long et al. (2023) | 30 | Single tDCS | True, sham and control stimulation (within-subjects) | True / sham: Right ATL; Control: Occipital lobe | tDCS applied to one member of the dyad (women) prior to naturalistic communication task | Decreased INS for true compared to the sham and control stimulation | No significant differences in verbal or nonverbal behaviors; Reduced emotional empathy for true compared to sham and control stimulation |
| Lu et al. (2023) | 62 | Dual-tACS, dual-tDCS | 20 Hz in-phase tACS, tDCS, sham (between subjects) | Right IFG | Six coordination blocks with stimulation in blocks 3 and 4 | Higher INS in PFC for tACS compared to tDCS and sham in block 5; Higher INS in right IFG during rest period after stimulation for tACS compared to tDCS; Reduced activation in right IFG for tDCS during stimulation compared to poststimulation |
Numbers of wins in blocks 3–6 higher than at baseline (block 1) in tACS and tDCS but not sham group, positive effect on number of wins in block 6 only for tACS not tDCS; Higher difference in reaction times (weaker coordination) in block 6 for tDCS compared to sham |
| Novembre et al. (2017) | 30 | Dual-tACS | frequency (within-subjects: 2 Hz, 10 Hz, 20 Hz) × relative phase (within-subjects: in-phase, anti-phase), sham stimulation | Left primary motor cortex | tACS during joint finger tapping task | NA | Increased synchrony for 20 Hz in-phase stimulation compared to anti-phase stimulation |
| Pan et al. (2021) | 24 | Dual-tACS | frequency (between-subjects: 6 Hz, 10 Hz) x relative phase (within-subjects: in-phase, antiphase, sham) | Left IFC | tACS during song learning task | NA | Increased synchrony for 6 Hz in-phase stimulation compared to 6 Hz sham stimulation; Improved intonation learning performance for 6 Hz in-phase compared to 6 Hz sham stimulation |
| Szymanski et al. (2017) | 38 | Dual-tACS | same-phase-same-frequency (6 Hz), different-phase-different-frequency (5 Hz and 7 Hz with 1 degree offset), 6 Hz sham (within-subjects) | Right frontal and parietal sites | tACS during joint drumming task | NA | Decreased synchrony for same-phase-same-frequency and the different-phase-different-frequency compared to sham |
tACS, transcranial alternating current stimulation; tDCS, transcranial direct current stimulation; IFC, inferior frontal cortex; ATL, anterior temporal lobe; IFG, inferior frontal gyrus; PFC, prefrontal cortex; STG, superior temporal gyrus; N/A, not applicable.