Quoting from Wikipedia page on Turing Test
The Turing test, developed by Alan Turing in 1950, is a test of a machine's ability to exhibit intelligent behaviour equivalent to, or indistinguishable from, that of a human. Turing proposed that a human evaluator would judge natural language conversations between a human and a machine designed to generate human-like responses. The evaluator would be aware that one of the two partners in conversation is a machine, and all participants would be separated from one another. The conversation would be limited to a text-only channel such as a computer keyboard and screen...
The definition made me wonder if we would term the captchas that show up on Google here it gives textual instructions to the user, bot or not, asking them to select images containing a specific object out of the given set of images.