The background is the experimental literature on zebra finch song learning. If one of these birds is raised in acoustic and social isolation, it never learns to sing a species-typical song, but rather continues to produce “proto-song”, which is a sort of songbird equivalent of grunts and groans. In contrast, with a relatively brief exposure to an example of adult song during a “critical period” early in life, a bird will (later on) learn to sing properly, in fact imitating the tutor’s song quite closely.

The punch line: a zebra finch raised in acoustic and social isolation, with “tutoring” by playback of its own vocalizations from a few moments before, acquires species-typical song in just about the same way as a bird raised with exposure to a “wild type” adult model.

It’s not just go playing computers that can learn from themselves.