Odor As a Contextual Cue in Memory Reactivation in Young Infants

Three-month-old infants were trained to move a mobile in the presence of a coconut or cherry odor (context). Six days later, a reactivation session took place. Infants were randomly assigned to 4 groups (same odor during training and reactivation, different odor during training and reactivation, no odor present during reactivation, no reactivation). A retention test was conducted 24h later in the presence of the training odor and mobile. Retention was seen only in the group of infants trained and reactivated with the same odor. This indicates that olfactory contextual cues function in a similar manner to visual and auditory contextual cues in that a novel context, or the absence of the context in which the memory was formed, are ineffective as reminders once the original memory has been forgotten.