A simpler and cheaper brain-stimulating intervention to improve language learning has been known in the literature since 1972. No fancy electronics necessary.

“The results of this study are interpreted as confirming the hypothesis that the ingestion of small amounts of alcohol, under certain circumstances, does lead to increased ability to authentically pronounce a second language.”[1]

Note that the improvement only happens after consuming exactly 1.5oz of cognac. Anything more than that and performance drops precipitously.

[1]https://deepblue.lib.umich.edu/bitstream/handle/2027.42/3404...