Mediating Role of Inhibition Control in the Relationship Between Age and Memory Changes Throughout Adulthood: An Aging Developmental Study in Iran

Introduction: This study aimed to investigate the age trends in various types of memory, including priming, working memory (WM), episodic memory (EM), and semantic memory (SM) from adulthood to old age, as well as the mediating role of inhibition control (IC) in the relationship between age and memory. Methods: A total of 796 healthy adults aged between 25 and 83 years participated in this cross-sectional study. They underwent assessment using a comprehensive battery of memory tests (adapted from the Betula battery), digit span tasks (to measure WM), and the Stroop color-word test (to measure IC). Results: The scatter plot with locally estimated scatterplot smoothing (LOESS) fitting line showed EM and WM declined steadily from age 25, while SM exhibited a mild increase up to age 55 followed by a decline. Priming did not show significant changes with age. Mediation analysis and bootstrap tests indicated that IC mediated the relationship between age and EM (β=-0.097, P=0.002) and between age and SM (β=-0.086, P=0.001). Conclusion: Our results showed that age affects various types of memory differently, and inhibition control plays a fundamental mediating role in explaining age-related declines in SM and EM.