Abstract: ObjectiveTo provide the early diagnosis of Alzheimer\'s disease(AD), the memory in the patients with mild cognitive impairment(MCI) was detected under the functional magnetic resonance imaging(fMRI), combined with the behavioral experiment.Methods9 patients with MCI and 9 controls matched for the age, gender, level of education and handedness performed encoding and retrieval of nonsense line drawings, presented visually while the MR machine was scanning. ResultsCompared with the controls, the patients manifested longer reaction time and lower correct ratio. The patients\' brain activation showed: the first episode of encoding of nonsense line drawings elicited distributed activation in bilateral dorsal lateral frontal lobes, left parahippocampus, bilateral temporal-occipital conjunction, parietal lobes and visual cortex in the control subjects. While these activations decreased in the second episode of encoding of the same stimuli, much stronger activation was found in most same areas during the retrieval phase except for the right parietal lobe, in which the patients showed stronger activation. Moreover, activation in the anterior cingulate cortex was observed only in the retrieval phase. The patients showed weaker and smaller activation in almost all activation areas during all tasks in the normal subjects. ConclusionThe patients with MCI have the deficit in memory. The examination of encoding and retrieval of nonsense line drawings by means of the behavioral experiment and fMRI test can offer a powerful reference for the early diagnosis of AD.

Key words: Alzheimer's disease(AD), mild cognitive impairment(MCI), memory, functional magnetic resonance imaging(fMRI)