Hsin-Te Chang & Mau-Sun Hua.
Recent research has proposed a preclinical stage of Alzheimer’s disease (AD), subjective memory decline (SMD), with the aim of detecting the disease and developing methods for subsequent intervention. It has been suggested that the objective memory function in individuals with SMD is normal. However, very limited study has investigated into different weights of semantic-associated processes of memory among individuals with SMD. Recent studies have suggested that memory could be differentiated into processes requiring high degrees of arbitrary associations or processes requiring high degrees of semantic associations. In a recent report of our team (Chang, Chen, Cheng, Lai, & Hua, in press), we compared the two memory processes among healthy controls with no memory complaints (HC), individuals with SMD, and patients with prodromal AD (i.e., amnestic mild cognitive impairment, aMCI) or early dementia of AD type (DAT), using neuropsychological tests with various loadings of semantic-related memory processes. It was found that as compared to the HC, individuals with SMD displayed impairment in forming arbitrary associations but not in forming semantic associations. In contrast, patients with aMCI or DAT displayed deficits in forming both types of associations. The study shed light on the potential early memory changes in AD and demonstrated that the memory decline among individuals with SMD may not be purely ‘subjective’ in nature.