While the research is of course impressive, it's a bit premature to extrapolate it to humans, or any other animal.
A sibling comment mentions trying it on mockingbirds; how about blackbirds, whose song never repeats (although it does show structure and they occasionally mimic)?
A very interesting topic, and I can't quite decide if a mind-machine interface would end up having a net positive or negative effect on our society...
More explicitly: there are many cases of regulation shaping the course that technology takes. It's a strawman (of the variety people are trying to call out here) to say that we're either helpless in the face of technology or we must halt its progress. There's a huge middle ground of regulating and guiding the process.
The most likely first application of this sort of research is as a sort of neural prosthetic for people with speech and/or movement disorders.
It will probably take a lot of doing to decrypt that mess reliably across a broad population. And think of the impact that culture and language will have! Surely people brought up in different systems of belief will think in different ways, their development having been shaped by different memetics and core ideals.
Maybe that's the sort of problem that deep learning and AI could help sift through. But I'm not sure that I'd want to train a nascent AI on the human subconscious. Didn't Poe address this sort of thing? "The Imp Of The Perverse?"
Hey, totally unrelated, does anyone have HBO's number? I think I got a pitch.
Oh, and you can't mention Mind-Machine Interfaces without the quote from Alpha Centauri :)
"I think, and my thoughts cross the barrier into the synapses of the machine - just as the good doctor intended. But what I cannot shake, and what hints at things to come, is that thoughts cross back. In my dreams the sensibility of the machine invades the periphery of my consciousness. Dark. Rigid. Cold. Alien. Evolution is at work here, but just what is evolving remains to be seen."
It is, of course, a spectrum. You can get a middle ground between the two extremes but it’s still a trade off between invasiveness (and the problems and concerns that come with that, such as rejection), precision (how many neurons worth of data is being averaged) and the need to probe many neurons to build an accurate model.
They're recording from HVC, an area of the bird brain that does that does motor planning. I think it'd be fair to say that HVC sits between the bird's intention to sing and the actual singing actions.
It's really impressive that they can decode enough to reproduce the song, but you could also access the song by....letting the bird sing it a fraction of a second later :-)
I sometimes evaluate the impact of the lack of privacy in personal thought in light of the possibility of demons/aliens/whatever a more-advanced species should be labeled, which are typically classified as non-omniscient (versus most definitions of God). The requirement of locality (non-omniprescence) seems to be the limiting factor, but this limitation is only effective in coordination with limits on long-range/high-speed capabilities, which could be augmented via unknown technologies. I think it is reasonable to assume that if such beings exist, human thought would not be kept private from them.
Nearly all technology interactions are recorded by various 3rd party companies; it seems the various collection and aggregation techniques employed by those companies and government agencies (across companies) already offer a few humans in a privileged position a sufficiently capable approximation to reading minds.
Though we all have to hope we uncover the source of truth in the brain so we can live forever embodied in some other medium :)
If not, it's terrifying.