Buildup of proactive inhibition as a function of temporal spacing and adult age

Glenberg's theory of temporal distinctiveness (Glenberg, 1987; Glenberg & Swanson, 1986) was used to examine whether the buildup of proactive inhibition (PI) may be interpreted as an overloading of temporal retrieval cues. The Brown-Peterson task was selected on the basis of the assumption that successful performance on such a task requires the use of a recency rule where the subject must use temporal cues to retrieve the contents of the most recent study list. Two variables were manipulated that were presumed to affect the utilization of temporal cues: length of intertrial interval (ITI) (0 or 90 s) and adult age (young or elderly). Glenberg's theory suggests that temporal spacing improves memory by enhancing the distinctiveness of temporal retrieval cues. Thus, it was predicted that PI buildup should be less in the 90-s condition than in the 0-s condition. Assuming that older adults are more sensitive to the overloading of temporal cues, it was anticipated that older adults would experience a greater buildup of PI than younger adults at the 0-s condition. Results showed that although PI buildup varied with length of ITI, it did not vary with adult age. Analysis of delayed measures of recall, recognition, and temporal memory suggested that a retrieval interpretation based on Glenberg's theory is insufficient as an explanation of the current results; encoding difficulties also appear to contribute to the buildup of PI.