The gear is pretty similar for tDCS, tACS (which uses alternating current at the "target" frequency"), and TI. Our data suggests that you can hit deep brain str

The gear is pretty similar for tDCS, tACS (which uses alternating current at the "target" frequency"), and TI. Our data suggests that you can hit deep brain structures with all of them (https://www.pnas.org/doi/10.1073/pnas.1815958116 https://www.pnas.org/doi/10.1073/pnas.1815958116) but TI has the advantage of focality: it avoids stimulating things between the scalp and the target. The other major difference is how it affects the neurons. tDCS, tACS and even TMS create electric fields that electrically polarize the neurons. TI...doesn't. The stimulus itself changes too rapidly and only the envelope fluctuates at the "target frequency." However, that envelope isn't real: something has to extract/demodulate it from the carriers and it's not entirely clear how--or how well--that happens.