any machines that measure emotion? (inability, people)

[nickerman]

Anything that can be hooked up to measure a persons emotion and wether it is positive or negative? I was thinking as I saw people placing orders in the coffee shop how when they recieved the order of the thing that they wanted there must have registered inside them a positive emotion but when they gave their money to pay for it it must have registered a negative emotion. No one likes to part with their money. I thought it would be nice to see how those emotions registered on a graph.

[Ottawa2011]

Polygraphs... sort of do that. "Mood rings" are almost a simple version of a polygraph--they indicate if blood pressure/body temperature is going up or down, which really just suggests that someone might be becoming more or less emotional about something.

[gelofogo]

There are tests that measure capacity for emotion, also. One of the conditions is alexithymia...inability to identify emotions in self, or in others. Are you asking about real-time detection, or capacity in general?