The cognitive neural mechanisms of age-related decline in mnemonic discrimination and its application

Abstract: Mnemonic discrimination (MD) refers to the ability to accurately distinguish similar memory experiences, which relies on a neural computing mechanism known as pattern separation. Currently, mnemonic similarity task (MST) is commonly employed to measure and study MD. The elderly tend to exhibit a noticeable decline in MD. This decline is proved to be associated with damage to the structural and functional integrity of the medial temporal lobe, which occurs during the aging process. Some researchers have also suggested that the aging of the neocortex can influence MD. Given its reliance on the medial temporal lobe, MD can reflect abnormal brain structural damage and functional decline in the early stages of cognitive impairment. Thus, MST has significant potential in early identification of cognitive impairment. To further explore the causes of the decline in MD, future studies should employ more advanced imaging techniques to separately investigate the effects of aging in the dentate gyrus and CA3 subregion on MD. It is also critical to explore the neural mechanisms underlying age-related changes in MD, with a particular focus on neocortical regions like the prefrontal cortex. Large-scale prospective cohorts should also be established to validate the effectiveness of MST in early identification of cognitive impairment.