The role of memory is central to the novel, introduced with the famous madeleine episode in the first section of the novel and in the last volume, "Time Regained", a flashback similar to that caused by the madeleine is the beginning of the resolution of the story. Throughout the work many similar instances of involuntary memory, triggered by sensory experiences such as sights, sounds and smells conjure important memories for the narrator and sometimes return attention to an earlier episode of the novel. Although Proust wrote contemporaneously with Sigmund Freud, with there being many points of similarity between their thought on the structures and mechanisms of the human mind, neither author read the other.