This allows colonists to experience an idealized version of life on Earth in a collective unconscious hallucination.

Perhaps this was a collective hallucination.

This may be the result of a collective hallucination, mind control or other tampering with survivors' perception.

A form of hysteria giving rise to collective hallucination - probably quite temporary,' said Willers.

If our technology can manufacture substances that induce delusions, could a much more advanced technology induce highly detailed collective hallucinations?

She appeared like a collective hallucination of some fantasy female.

From Coleman's point of view, the more resistant members of the faculty probably looked like people savoring a collective hallucination.

The way we at Chasm figure it, you had a collective hallucination.

And there you are - collective hallucination.

The cult of the Apocalypse has given us ample evidence that collective hallucinations are possible, so I don't discount the first suggestion.