My interpretation was that they would use cameras to measure frame rates and then look for the level at which lower frame rates reduced user happiness as measured through surveys. Pushing frame rates beyond that would be much less valuable.

I don't know anything about this test specifically but I cannot imagine that people were happier with lower frame rates.

They are just given as examples as ways Intel is getting quantifiable UX data. Probably more clear written as "quantified using tools ranging from high speed cameras mapping frame rates to user survey data"