2. Each subject must not report a history of memory decline with gradual onset and slow progression, that is either corroborated by an informant who knows the subject well or is documented in medical records. Each subject must have general cognitive function and activities of daily living sufficiently intact, based on clinical assessment, so as not to meet criteria for mild AD dementia (based on DSM-IV-TR(Diagnostic and Statistical Manual of Mental Disorders, 4th Edition) and NINCDS-ADRDA(National Institute of Neurological and Communicative Disorders and Stroke; Alzheimer's Disease and Related Disorders Association) criteria).