Figure 3.

Group differences in separation bias scores. A, B, Response proportions displayed in the top graphs were adjusted for age, sex, and education. C, The GHRD group had greater separation bias scores than the control group after controlling for age, sex, and education, indicating better memory performance in the GHRD group. This pattern of group difference was similar to that observed in younger versus older adults in a previous study, as shown in the bottom graphs (adapted from Yassa et al., 2011). In this previous study, the average age of the younger adults was 20 years and that of older adults was 70 years. Conversely, our participants were young to middle-aged (range 24–54; Table 1). Because our control participants were, on average, much older (mean = 40.6) than the younger participants in the previous study (mean = 20), it is possible that our control group already showed signs of cognitive aging, whereas the GHRD group did not.