Age-related elevations in intraindividual variability on associative memory tasks.

Age-related elevations in cognitive intraindividual variability (IIV) have been linked to reduced executive control associated with decline in frontal lobe function. However, the theoretical conceptualization of IIV in cognitive aging may be constrained by limited study of the extent to which age-related elevations in IIV may be observed on cognitive processes sensitive to aging, but not primarily reliant on frontal systems. To address this empirical gap, the present study investigated age-related differences in IIV on two associative memory tasks. Older adults showed elevated IIV on both tasks compared to younger adults. Elevated IIV was correlated with slowed response speed across both groups and tasks; IIV-accuracy correlations were mixed. Findings suggest that IIV may reflect age-related decline in distributed neural networks, including medial temporal regions, in addition to frontal systems dysfunction.