What was the first time someone became so immersed in a virtual world that they disassociated and felt like they were really there?
The term cyberspace has was coined in 1984 but I think the earliest case of thinking your body was out there operating away from your actual body was much earlier.
Infinity Beckoned is a brilliant book about Space exploration. There's one amazing bit where a geologist gets so engrossed in maneuvering the Soviet Lunokhod 1970 probe on the moon that he disembodies
'Focusing so intently on those TV images, Basilevsky's mind psycholog- ically uncoupled from his earthbound body and replanted itself inside of Lunokhod. As if he was somehow now inside the tub and peering out through its cameras. In this altered state of consciousness, any sense of time utterly disappeared. "The working session ended quite late-maybe at five a.m. or six," he said. "And I get out after the session, and I could see the moon in the sky. I could see Mare Imbrium, and it was for me like splitting of my brain or my conscious. I see the moon, it was there, but I was there too! I had that feeling and it was very strong." Basilevsky needed to unplug—to savor some tea and enjoy a bit of quiet solo hiking through the trees. Something tangible to plant both his feet on Earth again.'
It is possible there were earlier cases. Probably involving radar screens but this sort of disembodiment seems to require your brain having control over where your sense organs can look and see. A loop between doing and sensing.
