Source memory: extending the boundaries of age-related deficits.

Previous research has established that elderly adults can exhibit impaired memory for the source of newly acquired facts even when levels of fact recall in old and young do not differ. However, source memory impairments have been observed only under conditions of many-to-1 mapping: A large number of facts are related to either of 2 sources. It is thus possible that apparent source memory impairments reflect a more general age-related problem in handling many-to-1 mappings. Two experiments provide evidence against this possibility by demonstrating age-related source memory deficits with 1-to-1 mapping between facts and sources. The data also indicate that source memory deficits are observed across encoding tasks that manipulate the allocation of attention to the source or to the fact.