台大心理系

Neuropathological evidence suggests that semantic memory deterioration can occur earlier than episodic memory in the disease progression of dementia of the Alzheimer’s type (DAT). Increasing evidence has suggested marked semantic memory impairment in patients with amnestic mild cognitive impairment (aMCI). However, the predicative power of semantic memory on conversion from aMCI to DAT has remained inconsistent. In addition, no studies have directly investigated semantic memory among individuals with subjective cognitive decline (SCD). My study aims to investigate various aspects of semantic memory decline among aMCI patients, to evaluate the predictive values of these aspects of semantic memory on the DAT conversion, and to examine the semantic aspect of memory among SCD individuals. Individuals with SCD and patients with aMCI-single domain (aMCI-sd) suffered from disproportionately impaired performance on effortful and strategic retrieval of semantic memory, whereas those with aMCI-multiple domain (aMCI-md) suffered from deficits in both effortful and automatic retrieval of semantic memory. The conversion from aMCI-sd to DAT was predicted by poor performance in effortful retrieval of semantic memory. In contrast, the conversion from aMCI-md to DAT was predicted by poor performance on automatic retrieval. These findings suggest distinctive patterns and predictive values of semantic memory deterioration among individuals in preclinical stages of DAT.