Effects of Age on Contextually Mediated Associations in Paired Associate Learning

Older adults demonstrate an associative memory deficit that has been attributed to difficulty binding item information to contextual information (Naveh-Benjamin, 2000). Accounts of temporally-defined episodic associations that depend upon contextual retrieval (TCM Howard & Kahana, 2002) predict that a deficit in item-to-context binding will result in fewer backward (b-a) and transitive (a-c) associations. To measure group differences in backward and transitive associations, younger and older participants learned single function lists of paired associates with no contextual overlap (e.g., j-k, l-m) and double-function lists of paired associates consisting of chains of pairs (e.g., a-b, b-c). Although younger adults out-performed older adults on both pair types, there was a robust pair-type by age interaction. We suggest the older adults performed better than would be expected on the contextually overlapping double-function pairs due to an associative deficit in item-to-context binding, which resulted in the generation of fewer competing responses. Relative to younger adults, older adults made significantly more intrusions. Intrusion levels were normalized to equate for group differences and subsequent analysis indicated that younger adults made a larger proportion of associative intrusions to double-function probes than did older adults. The propensity of older adults to make fewer associative intrusions to double-function pairs suggests that older adults did not generate these associations. Thus, group differences in both correct recall probabilities and intrusion analysis suggest that backward and transitive associations are sensitive to aging. The results are discussed within the theoretical framework of the temporal context model and the hypothesis that older adults are impaired at forming new item-to-context associations