Contextual coding and recoding of infants' memories.

Six-month-old infants recognize a well-learned cue 24 h after training in the original context but not in a different one. In the present studies, we demonstrated that this contextually based retrieval deficit could be overcome if, following some training experience in one context, infants were briefly and passively exposed to a novel context. The impact of this procedure was retroactive, leading the immediately preceding training episode to be contextually recoded. However, it did not override the debilitating effect of a novel context on memory reactivation 3 weeks later and, surprisingly, it blocked the effectiveness of the actual training context as a reminder. We conclude that each individual training episode is encoded in terms of the context in which it occurs. The memory of a given episode, however, is recoded in terms of the most recent context in which it is active. This mechanism permits memories that are highly context-specific to be updated and subsequently retrieved in new and potentially appropriate settings.