A memory chamber is a special type of room that made use of the advanced technology of the Visitors. Located onboard their Motherships, it contains a bed with a single portal allowing outsiders to look inside. The chamber manipulated the cerebral cortex of those placed within it whereupon their memories are projected on screens. These images also invoked the emotions associated with those experiences which can be confusing to decipher if the subject is a Human.
Anna had Tyler Evans placed within the memory chamber in order to learn if he was the one for a Visitor experiment that involved her daughter Lisa. (Welcome to the War) Later, when Georgie Sutton was captured onboard the New York Mothership, he was interrogated and tortured for information which included being placed in the memory chamber. However, Marcus later reported to Anna that the chamber did not break the resistance fighter. (John May)