An improved lie detector?
Yep, I heard about this a few years ago. Apparently it’s near impossible to not have brain activity when presented with information you know. Not knowing about something, or a face, or a photo, etc. results with very boring inputs. However, when shown something you know something about, recognize a face, or a scene, etc. your brain goes nuts, even if you decide to answer, “I know nothing”.
The control tests indicated a 90+% accuracy rate of detecting deception. That said, they were careful to clarify, detecting a deception isn’t the same as guilt. If a suspect is shown a photo of a murdered body before this test, then the same photo is shown during the test, you’ll have an inflated response as you’ve seen it before.
The message was that you’d need to be very careful about interpreting the results. That said, when you’re a communist State, they may not care as much about that.