The Proust phenomenon, named after the author Marcel Proust (1871-1922), is the observation that particular odors may trigger reminders of autobiographical memories. There is some experimental evidence that olfactory stimuli can cue autobiographical memories more effectively than cues from other sensory modalities. The "petite Madeleines phenomenon" has been used to describe sudden triggering of memories in individuals with amnesia due to thalamic infarction.
Chu S, Downes JJ. Odor-evoked autobiographical memories: psychological investigations of Proustian phenomena. Chemical Senses 2000; 25: 111-116
Lucchelli F, Muggia S, Spinnler H. The "Petites Madeleines" phenomenon in two amnesic patients: sudden recovery of forgotten memories. Brain 1995; 118: 167-183