The "Lost in the Mall" experiment is a memory implantation technique used to demonstrate that confabulations about events that never took place – such as having been lost in a shopping mall as a child – can be created through suggestions made to experimental subjects. It was first developed by Jim Coan, an undergraduate student of psychologist Elizabeth Loftus as support for the claim that it is possible to implant entirely false memories in people. The technique was developed in the context of the debate about the existence of repressed memories and false memories.

Coan enlisted his mother, sister and brother as subjects. He assembled booklets containing four short narratives describing childhood events, and instructed them to try to remember as much as possible about each of the four events, and to write down those details over the course of six days. Unbeknown to the participants, one of the narratives was false; it described Coan's brother getting lost in a shopping mall at around the age of 5, then being rescued by an elderly person and reunited with his family. During the experiment, Coan's brother unwittingly invented several additional details of the false narrative. At the conclusion of the experiment—during a tape-recorded debriefing—when told that one of the narratives was false, Coan's brother could not identify which one and expressed disbelief when told.

Loftus calls this study "existence proof" for the phenomenon of false memory creation and suggests that the false memory is formed as a result of the suggested event (being lost in a mall) being incorporated into already existing memories of going to the mall. With the passage of time it becomes harder for people to differentiate between what actually happened and what was imagined and they make memory errors.