Pre-ejection period and skin conductance cannot distinguish between a positive challenge state and a negative threat state.

“those kinds of measures can't distinguish what we call a challenge type State that's almost like people have heard of flow where you're optimally balanced between important challenge you care about and resources and ability to you know overcome or at least deal with that challenge on the positive side in the other higher rousel state which is threat and that's again you're highly everything's highly engaged your whole stress system but you don't think you can deal with it”