I tried to detect emotions in students during group work.
The feedback gave they gave me was good (we hat fun, we were curious about the result, it judged this and that positiv/negative) but the faces mostly showed >neutral< (according to microsoft cognitive services and my own judgement).
Is there a research/book/source that worked on how concentration effects the expression of emotion? I guess that working hard just shoves the emotion in the background without deleting it.