In general there is a lot of work on ultrasound stimulation now, some of it is scary in other ways:

https://www.nature.com/articles/s41467-025-65080-9

which could imaginably lead to wireheading or something like Niven's "tasp".

There's also

https://news.ycombinator.com/item?id=46008332

Are these guys losers,clueless, or born psychopaths?

I hope for another category :)