Two friends, Sam and Maria, watch a documentary about a famous historical speech. A week later, they discuss it. Sam confidently, but incorrectly, recalls a specific powerful phrase being in the speech. Maria initially does not remember that phrase. However, after their conversation, Maria also begins to vividly recall hearing the same non-existent phrase. When a third friend asks her about the speech, Maria includes the incorrect phrase in her description, fully believing it was part of the original speech. Which psychological phenomenon best explains the change in Maria's memory?

Two individuals witness a staged crime as part of an experiment. Witness 1 initially tells an experimenter they remember the perpetrator wearing a green jacket. Later, Witness 1 overhears Witness 2 confidently telling another experimenter that the perpetrator's jacket was brown. When officially questioned a day later, Witness 1 now reports with certainty that the jacket was brown, genuinely believing their new memory is accurate. Which phenomenon provides the most specific explanation for the change in Witness 1's memory?