(CNN) Passengers at some European airports will soon be questioned by artificial intelligence-powered lie detectors at border checkpoints, as a European Union trial of the technology is set to begin.

Fliers will be asked a series of travel-related questions by a virtual border guard avatar, and artificial intelligence will monitor their faces to assess whether they are lying.

The avatar will become “more skeptical” and change its tone of voice if it believes a person has lied, before referring suspect passengers to a human guard and allowing those believed to be honest to pass through, said Keeley Crockett of Manchester Metropolitan University in England, who was involved in the project.

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