Meta Filter, [1973-75] is an interactive console, two participants sit on either side and look at a series of neutral images of people, people as individuals or people in relationship to others on the small screen in front of them. [more inside]
I came across this interesting bit of information while doing some research on the London based conceptual artist Stephen Willats. According to his wiki, "His 1973 work Meta Filter consisted of pairs of participants seated at a computer, attempting to reach an agreement about the meanings of various images and statements." You can read more about Meta Filter here, and more about Willats at his website here.